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[ARCHIVED THREAD] - DPM Recoil Reduction System vs. Hydraulic buffer EDIT: Armament LARB Mod 2 and 3 added to the test. (Page 2 of 4)
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Thanks for doing the legwork. I just noticed that they have an A5 length LARB buffer. Are you getting one of those? I would like to see a head to head against the RB5007 which I consider to be the best right now. If not....contact me offline and I may just buy one off Nick as well. Also, regarding the LARB and looking at this video by mbell: https://www.youtube.com/watch?v=ivMzu_HKgHw&t=581s Mike states how he reversed the spring and weight in the buffer and it brought the cyclic rate down another 39 RPM. Below is a pic taken from LARB's site showing the default spring and weight orientation. https://armamentusa.com/wp-content/uploads/2017/07/IMG_6336-157x157.jpg This is the same orientation I did in my CMMG RDB testing w/ my custom tungsten spring loaded carrier weight as seen in my picture below. http://c3junkie.com/wp-content/uploads/2018/10/Guard-556Tubb-9mmKynshot-A5-1_8OzTungsten-StrongSpring.jpg I think that orientation helps to reduce the initial recoil impulse. (not to get too off topic but if you follow my CMMG RDB testing, I stopped using the spring loaded carrier weight and instead modified the lugs of 5.45x39 bolts to control the delaying instead of throwing more mass at the issue). As I've mentioned before, I think that while documenting the cyclic rate is great data, it is not the deciding factor for me. I value smoothness more than cyclic rate. Picture below is the same configuration using the standard Colt 3.5 oz bolt weight and while it had a much slower cyclic rate, I found it to be too bouncy. http://c3junkie.com/wp-content/uploads/2018/10/Guard-556Tubb-9mmKynshot-A5-3_5ozColtWeight.jpg Again, in regards to cyclic rate, I personally don't pay much attention to any variation under 50 RPM if the results were taken on different days as just how well lubed the gun is will change your results. So going back to mbell's Youtube video.... @mbell or @99HMC4 Mike mentioned that he was going to ask Nick why he chose that spring/weight orientation. Mike did you get an answer from Nick? I personally think that while you may have a slower cyclic rate it may not be as smooth as the way Nick has it configured from the factory. However, there are so many variables. Caliber, gas system, ammo etc... You may have one configuration where you get a slower cyclic rate and you can't tell the difference in smoothness where another configuration you may have greater smoothness....maybe Nick chose that orientation as it is smoother across more configurations? Also, I see the picture below on the LARB site which is the Shrike or MCR upper. @99HMC4 what cyclic rates have you gotten with the Shrike/MCR? Which buffer? LARB Mod2 or 3 both? Spring details? https://armamentusa.com/wp-content/uploads/2018/12/83E0DC1C-E049-41CC-AB42-085ED97A0CF7.jpeg |
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Quoted: Be sure to specify the 'rate reducing buffer' which is apparently a newer version of the LARB that has a modified bumper tip, and potentially other components. |
Found this video. It's useless as a test but lets us see the DPM in it's package.
 Ultimate AR Buffer System from DPM Systems |
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Over my head. That means there are no lugs and no gas block correct? Lots of gas in the faces of us lefties? Quoted:
Quoted: It would be interesting to run subsonic .300 Blackout using a straight blowback bolt. |
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He is sending the LARB mod 2 and I will send the Rate Reducing Tailcap along. I don't think there are any other changes. The mod 3 is for the 5 position tube, is heavier/longer. Quoted:
Quoted: Be sure to specify the 'rate reducing buffer' which is apparently a newer version of the LARB that has a modified bumper tip, and potentially other components. |
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Worked in a LARB Mod 3 so Amphibian can test it in the A5 tube without spacers. So we have Hydraulic, DPM RRS, Armament LARB Mods 2 & 3, and some bumper caps.
Haven't heard back from Ammolytics about his accelerometer device yet. He said he would try to tweak it this weekend. <=1 ms is best since since phones only get ranges. If Amphibian winds up using a phone app we can always round the line chart as in my example to compensated for low sampling rate. Full auto should give an interesting graph, we can get an idea of smoothness between impulses. I don't think anyone is up to spending 400 for the Spuhr scope mount but there should be a way to use accessory rail mounts to mount it on there level. We could strap it to the handguard somehow but a solid mount will be level and give us more reliable readings. Attached File UPDATE: Eric (Ammolytics) says he may have the tweaking done by end of week to get to 1 ms. There is a printed picatinny rail enclosure someone else created and if he can get one the mounting issue will be solved. Ammolytics Accelerometer Printed Enclosure I encourage anyone following this to support Ammolytics on Patreon (check the blog link). He is doing quite a bit of work in several areas to advance innovation in firearms tech. It's a monthly thing (starting at 2 bucks). You can cancel anytime. |
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Can't we mount it directly to the pic rail? This isn't an accuracy test - it could be run @ 5 yards from the berm, as long as there's no rocks. I don't want to make amphibian remove his optic, but it doesn't sound as if it's needed unless he's testing other things @ the same time.
In 15 years, we'll have optics that range the target and adjust the recticle accordingly, a windmeter on top, the recticle will tell you how many rounds left in the mag, the computer will measure muzzle velocity and recoil, as well as chamber pressure... |
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Can't we mount it directly to the pic rail? This isn't an accuracy test - it could be run @ 5 yards from the berm, as long as there's no rocks. I don't want to make amphibian remove his optic, but it doesn't sound as if it's needed unless he's testing other things @ the same time. In 15 years, we'll have optics that range the target and adjust the recticle accordingly, a windmeter on top, the recticle will tell you how many rounds left in the mag, the computer will measure muzzle velocity and recoil, as well as chamber pressure... There is a lot to do on his end. I offered to do the accelerometer testing and data crunching separately so Amphibian can focus on his cutaway tube video and basic testing of the buffers. We can limit the test to 5.56/Tubb/suppressed and the 3 buffers to start for subjective smoothness and rate of fire. The accelerometer can confirm his subjective felt recoil tests but I don't think it can replace them. He may want to tackle the whole shebang though. |
I’m interested to see what happens....
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Thanks for doing the legwork. I just noticed that they have an A5 length LARB buffer. Are you getting one of those? I would like to see a head to head against the RB5007 which I consider to be the best right now. If not....contact me offline and I may just buy one off Nick as well. Also, regarding the LARB and looking at this video by mbell: https://www.youtube.com/watch?v=ivMzu_HKgHw&t=581s Mike states how he reversed the spring and weight in the buffer and it brought the cyclic rate down another 39 RPM. Below is a pic taken from LARB's site showing the default spring and weight orientation. https://armamentusa.com/wp-content/uploads/2017/07/IMG_6336-157x157.jpg This is the same orientation I did in my CMMG RDB testing w/ my custom tungsten spring loaded carrier weight as seen in my picture below. http://c3junkie.com/wp-content/uploads/2018/10/Guard-556Tubb-9mmKynshot-A5-1_8OzTungsten-StrongSpring.jpg I think that orientation helps to reduce the initial recoil impulse. (not to get too off topic but if you follow my CMMG RDB testing, I stopped using the spring loaded carrier weight and instead modified the lugs of 5.45x39 bolts to control the delaying instead of throwing more mass at the issue). As I've mentioned before, I think that while documenting the cyclic rate is great data, it is not the deciding factor for me. I value smoothness more than cyclic rate. Picture below is the same configuration using the standard Colt 3.5 oz bolt weight and while it had a much slower cyclic rate, I found it to be too bouncy. http://c3junkie.com/wp-content/uploads/2018/10/Guard-556Tubb-9mmKynshot-A5-3_5ozColtWeight.jpg Again, in regards to cyclic rate, I personally don't pay much attention to any variation under 50 RPM if the results were taken on different days as just how well lubed the gun is will change your results. So going back to mbell's Youtube video.... @mbell or @99HMC4 Mike mentioned that he was going to ask Nick why he chose that spring/weight orientation. Mike did you get an answer from Nick? I personally think that while you may have a slower cyclic rate it may not be as smooth as the way Nick has it configured from the factory. However, there are so many variables. Caliber, gas system, ammo etc... You may have one configuration where you get a slower cyclic rate and you can't tell the difference in smoothness where another configuration you may have greater smoothness....maybe Nick chose that orientation as it is smoother across more configurations? Also, I see the picture below on the LARB site which is the Shrike or MCR upper. @99HMC4 what cyclic rates have you gotten with the Shrike/MCR? Which buffer? LARB Mod2 or 3 both? Spring details? https://armamentusa.com/wp-content/uploads/2018/12/83E0DC1C-E049-41CC-AB42-085ED97A0CF7.jpeg  LARB recoil buffer I got the cycle rate damn low at times with the LARB. I don’t remember the exact numbers, I think I got it down to 800RPM at one time. The spring/weight set up is what it is due to countless rounds/testing. People seem to think I just put something together and called it good. We went through many designs, had very well known people/companies in the industry test and give feedback and simple “well that didn’t work, let’s do this” R&D. All the testing ideas everyone is suggesting here, we’ve already done ourselves in some shape or form. We just don’t release every finding, we keep a lot of data to ourselves. Nothing’s perfect and EVERY product can be improved on. The weight is set up that way due to a few things. Controls bolt bounce better, controls unlocking the way I wanted and gave us the best overall feel and performance. I made adjustable weights to adjust weight travel, I made weights with springs on both sides, I ran weights with spring in the rear, I’ve run light springs, I’ve run heavy springs, I’ve had countless drain changes and variations. The spring rate I use is that for a reason, not just whatever spring I found that fit. The durometer of the tail cap and internal pad are what they are for a reason, the shape of the tail cap is an actual design that has a compression factor formula for that durometer urethane at a given bolt speed and force. It’s a simple design but it’s all engineered. It works well and I welcome more feedback... |
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Quoted:  https://www.youtube.com/watch?v=Olh8vtUzyh0I got the cycle rate damn low at times with the LARB. I don’t remember the exact numbers, I think I got it down to 800RPM at one time. The spring/weight set up is what it is due to countless rounds/testing. People seem to think I just put something together and called it good. We went through many designs, had very well known people/companies in the industry test and give feedback and simple “well that didn’t work, let’s do this” R&D. All the testing ideas everyone is suggesting here, we’ve already done ourselves in some shape or form. We just don’t release every finding, we keep a lot of data to ourselves. Nothing’s perfect and EVERY product can be improved on. The weight is set up that way due to a few things. Controls bolt bounce better, controls unlocking the way I wanted and gave us the best overall feel and performance. I made adjustable weights to adjust weight travel, I made weights with springs on both sides, I ran weights with spring in the rear, I’ve run light springs, I’ve run heavy springs, I’ve had countless drain changes and variations. The spring rate I use is that for a reason, not just whatever spring I found that fit. The durometer of the tail cap and internal pad are what they are for a reason, the shape of the tail cap is an actual design that has a compression factor formula for that durometer urethane at a given bolt speed and force. It’s a simple design but it’s all engineered. It works well and I welcome more feedback... We may find out no buffer outperforms the others so price point and reliability could wind up to be deciding factors. No matter though, can't know for sure until we try it. Btw I am really curious about the LARB Rate Reducing bumper (taper inside and outside ends) and how it affects things. |
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Thanks for the video. Looks pretty darn smooth. Rate of fire in the 600's seems most smooth for my setup but not everyone is concerned about full auto. We may find out no buffer outperforms the others so price point and reliability could wind up to be deciding factors. No matter though, can't know for sure until we try it. Btw I am really curious about the LARB Rate Reducing bumper (taper inside and outside ends) and how it affects things. |
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Give it a try with the MOD2 and MOD3 I'm sending! Mbell has one, I haven't heard any reports yet and Machineguns Vegas has one but Bebe won't report either.... Quoted:
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Thanks for the video. Looks pretty darn smooth. Rate of fire in the 600's seems most smooth for my setup but not everyone is concerned about full auto. We may find out no buffer outperforms the others so price point and reliability could wind up to be deciding factors. No matter though, can't know for sure until we try it. Btw I am really curious about the LARB Rate Reducing bumper (taper inside and outside ends) and how it affects things. |
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I'll definitely see how the Mod3 performs in my Shrike. I'm getting 630 RPM now with my hydraulic Kynshot RB5007, A5 and 308 Tubb flat spring and it is very smooth.  I honestly don’t remember. It was so slow I could keep up in semi, I remember that. Maybe it’s at 800 now, I don’t know anymore. The one in that video was one of the slowest I had it. I wanted it faster, so I went lighter. My Shrike didn’t really like the MOD3 at 5oz, I runs best at 6-7oz. But I do have a ton of gas port work and feed work. I ran a Strike Industries flat wire spring for a few years in it, ran very well and very quiet. But, there’s a few inherent flaws with flat wire springs. One reason we teamed up with SprinCo.
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Quoted: Give it a try with the MOD2 and MOD3 I’m sending! Mbell has one, I haven’t heard any reports yet and Machineguns Vegas has one but Bebe won’t report either.... |
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Quoted: I ran a Strike Industries flat wire spring for a few years in it, ran very well and very quiet. But, there's a few inherent flaws with flat wire springs. One reason we teamed up with SprinCo. I think for standard round springs, SprinCo's are the best. I've spoken to Alan several times when I had my business and used to sell his springs on my site. However, all that said, I'm now a fan of the Tubb flat springs. I've never gotten my Shrike and other configurations to run as slow and as smooth as my current configurations which are using Tubb flat wire springs. So what are these 'multiple' (since you said, "few") flaws with flat wire springs? |
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I've never use Strike Industries flat wire springs. Only Tubbs. I think for standard round springs, SprinCo's are the best. I've spoken to Alan several times when I had my business and used to sell his springs on my site. However, all that said, I'm now a fan of the Tubb flat springs. I've never gotten my Shrike and other configurations to run as slow and as smooth as my current configurations which are using Tubb flat wire springs. So what are these 'multiple' (since you said, "few") flaws with flat wire springs? |
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I'm curious if Tubb springs and Strike springs are made in the same machine? I have several Strike flat wire springs in rifle/carbine length, they do work very well. Flaws in flat wire springs (a spring design, NOT a firearm thing) in any application lie in the manufacturing process. Basically stresses cannot be controlled and spring rates (linear compression rates) are hard to control. Both lead to instabilities in rate and life span/working/duty cycle. This is REALLY splitting hairs as 99.999999% of shooters will never touch in these. But it is there. SprinCos are nice cause of their consistency and the ability to actually use different spring rates. Flat wire springs are what they are. That being said, they do work well, are very quiet and if it works, run it. Quoted:
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I've never use Strike Industries flat wire springs. Only Tubbs. I think for standard round springs, SprinCo's are the best. I've spoken to Alan several times when I had my business and used to sell his springs on my site. However, all that said, I'm now a fan of the Tubb flat springs. I've never gotten my Shrike and other configurations to run as slow and as smooth as my current configurations which are using Tubb flat wire springs. So what are these 'multiple' (since you said, "few") flaws with flat wire springs? Are you 100% sure that the springs David Tubb is selling are not controlled properly? All I know is that I've had excellent results with the Tubb flat wire springs. I find that what he explains in his video: https://www.youtube.com/watch?v=8fMVZbrnvu8&t=153s to be totally true. The Shrike for example requires a strong spring to strip rounds from the links. An orange (308) SprinCo or Ares supplied spring will be around 13.9 lbs of force with the bolt in forward position while it will be 24.8 lbs when the bolt is to the rear. While the 308 Tubb Flat spring is 13lbs with the bolt forward and only 16.7lbs in the open position. Having almost the same amount of force with the bolt open or closed makes for a smoother operating action in my opinion. (just as David Tubb mentions in his video). It certainly keeps the cyclic rate down....again, making a gun run slow has never been an issue for me. Making it run slow AND smooth is harder to do. I still have my Sprinco springs. When I get around to testing your buffer, please tell me what springs you want me to use to test your buffer since it sounds like you have designed around using Sprinco springs. Again, when I had my business, I spoke to Alan at Sprinco and he agreed to use a standard White Sprinco spring since I was controlling the gas when testing with the 10.3" MK18. So I was planning to do the same here. I was going to do that as a baseline configuration, H2 buffer, White Sprinco, .70" gas port, M855 ammo. Then test the other buffers using the Tubb flat springs as that is what I've found to be the smoothest and don't jack up the cyclic rate like regular round springs do...but again, for testing your product, I can just stick to Sprinco. |
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So are you saying that if someone were to control the stresses and spring rates then they would be OK by you? Are you 100% sure that the springs David Tubb is selling are not controlled properly? All I know is that I've had excellent results with the Tubb flat wire springs. I find that what he explains in his video: https://www.youtube.com/watch?v=8fMVZbrnvu8&t=153s to be totally true. The Shrike for example requires a strong spring to strip rounds from the links. An orange (308) SprinCo or Ares supplied spring will be around 13.9 lbs of force with the bolt in forward position while it will be 24.8 lbs when the bolt is to the rear. While the 308 Tubb Flat spring is 13lbs with the bolt forward and only 16.7lbs in the open position. Having almost the same amount of force with the bolt open or closed makes for a smoother operating action in my opinion. (just as David Tubb mentions in his video). It certainly keeps the cyclic rate down....again, making a gun run slow has never been an issue for me. Making it run slow AND smooth is harder to do. I still have my Sprinco springs. When I get around to testing your buffer, please tell me what springs you want me to use to test your buffer since it sounds like you have designed around using Sprinco springs. Again, when I had my business, I spoke to Alan at Sprinco and he agreed to use a standard White Sprinco spring since I was controlling the gas when testing with the 10.3" MK18. So I was planning to do the same here. I was going to do that as a baseline configuration, H2 buffer, White Sprinco, .70" gas port, M855 ammo. Then test the other buffers using the Tubb flat springs as that is what I've found to be the smoothest and don't jack up the cyclic rate like regular round springs do...but again, for testing your product, I can just stick to Sprinco. |
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To be honest, I'd prefer to have zero influence on your tests. The LARB was designed d to not only be a very precise component, but to also be very forgiving. 99% of my customers just want it to work when the out it in their weapon. It should run (within reason) with any spring, fine tuning is an option. The way I see it, whatever you find is a good thing. Good, bad it all leads to a better end product.... I've posted that I have a lot of different configurations I run on the M16 platform and have already posted here and on my website what I think is the smoothest...however, I obviously have not tried every buffer or combination out there and am always willing to try something new. I have no doubt your buffer will work....but if I was just looking for something to just work, I'd honestly just stick with the tried and true milspec H2. Every configuration I have that utilizes the buffer tube works with the H2. I believe that anything that is gas operated, step 1 is to not have an overgassed setup...there is only so much buffers/springs can do. All of my setups are already configured to use the right amount of gas to run an H2 buffer in full auto.....and that is 5.56, 300BLK, 5.45x39, 7.62x39 etc...they all run with an H2. For years, I only ran my Shrike with the H2 since I had the lug shear off on me and going too heavy just puts more stress on the impact lug of the carrier and op rod and didn't want to break another carrier. For the 9mm CMMG RDB, I've cut my own bolt lug angles to control the 'unlocking' of the bolt since it is not gas operated. For the belt fed FM9 it is straight blowback so much can be done there but again, I think my preferred setup is the smoothest I've tried bring the cyclic rate down to 450 RPM and running pretty smooth for a straight blowback. This testing will be time consuming. I know I can't please everyone but I welcome your input on what YOU think will be the smoothest with the least amount of dot bounce....not just if it will work or not. I don't doubt that any of the buffers will run fine. Again, the 10.3" MK18 will be baseline configuration that I will be testing. I will only use LC M855 for the testing to keep things consistent as possible. Since you are the inventor of the LARB, I would think you may have a suggested configuration that you think runs the smoothest and if so, I'd like to know what that is. Again, I think running a Tubb flat spring would yield the best results with your buffer (or just about any buffer for that matter) but you don't seem to like the flat springs so I'd like know what you think works better. I've got Sprinco springs too so I'll just go back to that if you think that is the best for your buffer. (I would still test with the Tubb for other buffers). I'm really hoping the accelerometer works well as I think comparing how smooth something is can be very subjective. I hope to just get some numbers with that device and my cyclic rate timer. I'm thinking to fire each configuration in a lead sled for 5 rounds to take accelerometer readings. Then do 10 round mag dumps in full auto standing to record cyclic rates. When I do the 10 round mag dumps, I will get a feel for each configuration and pay attention to smoothness and dot bounce but again nothing to really quantify that...which is why I'm hoping the accelerometer gives us some good data.....now that I think about it. Maybe we should put the FerFrans RRS carrier into the test. When I did that testing, the FerFrans certainly works and got the cyclic rate down a lot....474 RPM....documented here: https://www.ar15.com/forums/Armory/Ferfrans-Bolt-Carrier/23-493014/#i5050320 While slow, I felt that is wasn't smooth at all....like it was a timing issue. Maybe we should put the accelerometer on that setup and I would hope it could illustrate what I think is happening. If the data from the accelerometer does not illustrate that it isn't smooth then maybe the data isn't useful....for that matter, how about a comparison of my CMMG 9mm RDB that I have tuned to run as smooth as my MP5 and then run one of my 9mm straight blowback setups. I know that is night and day everyone can tell a difference in those two configurations. If the acclerometer cannot illustrate the drastic difference there then it may not be worth using it. @HDSledge...do you want to test the accelerometer comparing your CMMG RDB to a straight blowback 9mm before sending to me and see what kind of data you get? |
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@HDSledge...do you want to test the accelerometer comparing your CMMG RDB to a straight blowback 9mm before sending to me and see what kind of data you get? Btw last I heard from Eric at Ammolytics he has the accelerometer sensitivity up to 700 KHz. He is working on getting to 1,000 which would give us 1 ms increments. |
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Thanks for your response. I think we are all just trying to find out what is going to be the smoothest setup with the least amount of dot bounce. I've posted that I have a lot of different configurations I run on the M16 platform and have already posted here and on my website what I think is the smoothest...however, I obviously have not tried every buffer or combination out there and am always willing to try something new. I have no doubt your buffer will work....but if I was just looking for something to just work, I'd honestly just stick with the tried and true milspec H2. Every configuration I have that utilizes the buffer tube works with the H2. I believe that anything that is gas operated, step 1 is to not have an overgassed setup...there is only so much buffers/springs can do. All of my setups are already configured to use the right amount of gas to run an H2 buffer in full auto.....and that is 5.56, 300BLK, 5.45x39, 7.62x39 etc...they all run with an H2. For years, I only ran my Shrike with the H2 since I had the lug shear off on me and going too heavy just puts more stress on the impact lug of the carrier and op rod and didn't want to break another carrier. For the 9mm CMMG RDB, I've cut my own bolt lug angles to control the 'unlocking' of the bolt since it is not gas operated. For the belt fed FM9 it is straight blowback so much can be done there but again, I think my preferred setup is the smoothest I've tried bring the cyclic rate down to 450 RPM and running pretty smooth for a straight blowback. This testing will be time consuming. I know I can't please everyone but I welcome your input on what YOU think will be the smoothest with the least amount of dot bounce....not just if it will work or not. I don't doubt that any of the buffers will run fine. Again, the 10.3" MK18 will be baseline configuration that I will be testing. I will only use LC M855 for the testing to keep things consistent as possible. Since you are the inventor of the LARB, I would think you may have a suggested configuration that you think runs the smoothest and if so, I'd like to know what that is. Again, I think running a Tubb flat spring would yield the best results with your buffer (or just about any buffer for that matter) but you don't seem to like the flat springs so I'd like know what you think works better. I've got Sprinco springs too so I'll just go back to that if you think that is the best for your buffer. (I would still test with the Tubb for other buffers). I'm really hoping the accelerometer works well as I think comparing how smooth something is can be very subjective. I hope to just get some numbers with that device and my cyclic rate timer. I'm thinking to fire each configuration in a lead sled for 5 rounds to take accelerometer readings. Then do 10 round mag dumps in full auto standing to record cyclic rates. When I do the 10 round mag dumps, I will get a feel for each configuration and pay attention to smoothness and dot bounce but again nothing to really quantify that...which is why I'm hoping the accelerometer gives us some good data.....now that I think about it. Maybe we should put the FerFrans RRS carrier into the test. When I did that testing, the FerFrans certainly works and got the cyclic rate down a lot....474 RPM....documented here: https://www.ar15.com/forums/Armory/Ferfrans-Bolt-Carrier/23-493014/#i5050320 While slow, I felt that is wasn't smooth at all....like it was a timing issue. Maybe we should put the accelerometer on that setup and I would hope it could illustrate what I think is happening. If the data from the accelerometer does not illustrate that it isn't smooth then maybe the data isn't useful....for that matter, how about a comparison of my CMMG 9mm RDB that I have tuned to run as smooth as my MP5 and then run one of my 9mm straight blowback setups. I know that is night and day everyone can tell a difference in those two configurations. If the acclerometer cannot illustrate the drastic difference there then it may not be worth using it. @HDSledge...do you want to test the accelerometer comparing your CMMG RDB to a straight blowback 9mm before sending to me and see what kind of data you get? |
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Is there a way to measure the muzzle bounce, or better yet, the reticle? Maybe with a video recording? That's the real goal here, and as much as I like accelerometers, it isn't always obvious how to correlate the results to what the shooter perceives. |
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Quoted: My personal opinion and my personal experience, the smoothest combo I’ve run is; LARB and Strike flat wire carbine spring, Sprinco yellow (reduces power) spring and hot white spring. I haven’t done enough “scientific” test yet to determine why, but my calibrated shoulder works. The flat wire spring is the quietest, which we (people in general) automatically equate to “smooth”. Weather the numbers are there or not. The reduced power spring felt very nice too. Well, I’m here to help, this is right up my alley! Let me know what I can do to help, there’s always room for improvement... One thing I just realized: Spring loaded buffer spring forces/tension can be changed pretty easily but with a hydraulic buffer you can't change diddly squat. Sorta puts spring loaded buffers at an advantage from the gitgo. The DPM RRS comes with a couple springs and weights so it is somewhat configurable. Could make good options for the LARB as well. I've been wondering about hydraulic buffers: In a hydraulic buffer is the compression time frame set or does it vary depending on ammo, such as with hot loads or subs? Ex. On my hydraulic lift no matter how much weight is on the platform, it will still lower the load at the same rate. Same principle for hydraulic buffers? |
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Did you get a chance to compare your LARB against a hydraulic buffer? If so how did they compare from your perspective? One thing I just realized: Spring loaded buffer spring forces/tension can be changed pretty easily but with a hydraulic buffer you can't change diddly squat. Sorta puts spring loaded buffers at an advantage from the gitgo. The DPM RRS comes with a couple springs and weights so it is somewhat configurable. Could make good options for the LARB as well. I've been wondering about hydraulic buffers: In a hydraulic buffer is the compression time frame set or does it vary depending on ammo, such as with hot loads or subs? Ex. On my hydraulic lift no matter how much weight is on the platform, it will still lower the load at the same rate. Same principle for hydraulic buffers? |
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Thanks for your response. I think we are all just trying to find out what is going to be the smoothest setup with the least amount of dot bounce. I've posted that I have a lot of different configurations I run on the M16 platform and have already posted here and on my website what I think is the smoothest...however, I obviously have not tried every buffer or combination out there and am always willing to try something new. Again, I think running a Tubb flat spring would yield the best results with your buffer (or just about any buffer for that matter) but you don't seem to like the flat springs so I'd like know what you think works better. I've got Sprinco springs too so I'll just go back to that if you think that is the best for your buffer. (I would still test with the Tubb for other buffers). I'm really hoping the accelerometer works well as I think comparing how smooth something is can be very subjective. I hope to just get some numbers with that device and my cyclic rate timer. I'm thinking to fire each configuration in a lead sled for 5 rounds to take accelerometer readings. Then do 10 round mag dumps in full auto standing to record cyclic rates. When I do the 10 round mag dumps, I will get a feel for each configuration and pay attention to smoothness and dot bounce but again nothing to really quantify that...which is why I'm hoping the accelerometer gives us some good data.....now that I think about it. Maybe we should put the FerFrans RRS carrier into the test. Quoted:
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To be honest, I'd prefer to have zero influence on your tests. The LARB was designed d to not only be a very precise component, but to also be very forgiving. 99% of my customers just want it to work when the out it in their weapon. It should run (within reason) with any spring, fine tuning is an option. The way I see it, whatever you find is a good thing. Good, bad it all leads to a better end product.... I've posted that I have a lot of different configurations I run on the M16 platform and have already posted here and on my website what I think is the smoothest...however, I obviously have not tried every buffer or combination out there and am always willing to try something new. Again, I think running a Tubb flat spring would yield the best results with your buffer (or just about any buffer for that matter) but you don't seem to like the flat springs so I'd like know what you think works better. I've got Sprinco springs too so I'll just go back to that if you think that is the best for your buffer. (I would still test with the Tubb for other buffers). I'm really hoping the accelerometer works well as I think comparing how smooth something is can be very subjective. I hope to just get some numbers with that device and my cyclic rate timer. I'm thinking to fire each configuration in a lead sled for 5 rounds to take accelerometer readings. Then do 10 round mag dumps in full auto standing to record cyclic rates. When I do the 10 round mag dumps, I will get a feel for each configuration and pay attention to smoothness and dot bounce but again nothing to really quantify that...which is why I'm hoping the accelerometer gives us some good data.....now that I think about it. Maybe we should put the FerFrans RRS carrier into the test. As far as testing goes, one thing that might be interesting / show the overall effectiveness, is a full auto burst dispersion test between the systems. Say, a torso sized target at 15-25yds, with a 8" shoot n see target in the center to focus the sights on. When you do the 10rd mag dump, you also try and track the 8" target through the sights. The 'pattern' of the various 10rd bursts will help show overall controllability of the system; the tighter / more accurate the 10rd burst, likely the better/smoother/easier to track the sights with. Tighter/more accurate burst fire is the goal of the Ultimax, for example. This could be especially helpful in distinguishing buffers with otherwise comparable RPM's. Example, if the H2 buffer runs 850rpm, and the H2+EAB tip also runs 850rpm - but the EAB produces a noticeably tighter burst dispersion - that will show that the EAB is reducing overall weapon vibration even if it isn't lowering RPM. Example: 
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Did you get a chance to compare your LARB against a hydraulic buffer? If so how did they compare from your perspective? One thing I just realized: Spring loaded buffer spring forces/tension can be changed pretty easily but with a hydraulic buffer you can't change diddly squat. Sorta puts spring loaded buffers at an advantage from the gitgo. The DPM RRS comes with a couple springs and weights so it is somewhat configurable. Could make good options for the LARB as well. I've been wondering about hydraulic buffers: In a hydraulic buffer is the compression time frame set or does it vary depending on ammo, such as with hot loads or subs? Ex. On my hydraulic lift no matter how much weight is on the platform, it will still lower the load at the same rate. Same principle for hydraulic buffers? As mentioned I personally never liked the original Enidine or the standard RB5000 Kynshot. Both are about the same stiffness and don't seem to do much to me. I think they are better suited for overgassed guns...which most people have. In my testing, I like the hydraulics that take about 5lbs to compress. I think this is a sweet spot that works across almost all of my configurations very smoothly. |
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Quoted: Honestly... I've personally never ran the hydraulic buffer against my LARB head to head. I've had customers that did, I've shot both and I like mine better, but I haven't ever done a real side by side. I've done that against the MGI rate reducing buffer. I'm not a fan of hydraulic buffers, at all. And to be blunt, with the LARB you can get the same (or very close) cyclic rates (which translates into same bolt speed in semi auto), anti tilt, carrier alignment, controlled unlocking and not worry about it leaking. Ever. No BS, the LARB is a tank that will put last the weapon and it works very well. I've thought about more "tunable options", but it's just to much. Aside from the design and R&D/Manufacturing aspects, bringing a product to market that works well for "everyone" is not an easy task. The DPM RRS buffer is cool. But complicated. I played with them and the owner and I talked about our designs together at SHOT a few years ago. I respect it, but it's too much. My design is already making a simple component more complicated. The LARB pretty much works in everything, no adjusting or tuning. It will pretty much improve and work in any weapon it fits it. There's always ways to taylor it to a specific set up, but I can't and won't offer that. It's not feasible. I do offer weights and technical help for this very reason though... As I posted earlier, if I wanted something that would just work and not be concerned about the best performance, I would just stay with an H2. All my stuff is already tuned to run an H2 with a white Sprinco spring and carbine buffer tube. However, in my testing I've found that almost all of my configurations will run just fine with my preferred setup. So if I want a 'bombproof' setup, I can just swap buffers out for a Vltor A5 and be good to go. I've had an original 1970's or so era Colt hydraulic leak on me. Enidine has never leaked but as posted above, never liked it and so my round counts weren't high. Never had any Kynshot leak but have had the head snap off which they replaced and updated the design so that supposedly won't happen again. I totally get what you say about all the tunable options. When I was in business selling my MicroMOA Govnah, I offered I think too many options for the average 'joe'. I offered the ability for users to drill their own regulator plates to whatever port sizes they wanted or I would drill them for the customer. Most people didn't know what a numbered drill bit set was and very few would read all the information I had on my site to tune things themselves. I did get a lot of questions on a regular basis. New products come out on a regular basis and it is practically impossible to plan for every scenario. I've run into scenarios where you change from a milspec trigger or Geissele trigger to a Hiperfire and the Hiperfire requires less gas to run. Changing to a JP SCS also requires less gas. Change ammo and that all changes too. People that reload brings up a whole set of variables. How the barrel is chambered will also affect how much gas is required. Tighter chamber / shorter leade in the rifling will affect optimal port sizing as well. |
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Quoted: Personally, I'd like to see all buffers (H2; H2 w/ EAB and LARB Tip; DPM; LARB; Hydraulic buffer) all tested with the same Tubb flatwire. That way there's no extra variable of different springs to account for. As far as testing goes, one thing that might be interesting / show the overall effectiveness, is a full auto burst dispersion test between the systems. Say, a torso sized target at 15-25yds, with a 8" shoot n see target in the center to focus the sights on. When you do the 10rd mag dump, you also try and track the 8" target through the sights. The 'pattern' of the various 10rd bursts will help show overall controllability of the system; the tighter / more accurate the 10rd burst, likely the better/smoother/easier to track the sights with. Tighter/more accurate burst fire is the goal of the Ultimax, for example. This could be especially helpful in distinguishing buffers with otherwise comparable RPM's. Example, if the H2 buffer runs 850rpm, and the H2+EAB tip also runs 850rpm - but the EAB produces a noticeably tighter burst dispersion - that will show that the EAB is reducing overall weapon vibration even if it isn't lowering RPM. Example: https://www.recoilweb.com/wp-content/uploads/2018/03/Surefire_OBC01.jpg I would rank it this way in regards to objectivity: 1. full auto cyclic rate - again, not a determining factor in smoothness but it is a good data point, repeatable and no human influence. 2. accelerometer data - again, will be great...in theory...need to actually do some testing with it, should be repeatable and no human influence 3. hi speed camera video - will be very informative to see how the varying systems do in action, repeatable and no human influence 4. full auto dispersion testing, may or may not be repeatable and has the greatest amount of human influence |
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I'm new to the issue of adjusting gas to tweak how an AR runs. In a fixed non-adjustable gas block (like in my spikes uppers) is there a number or default gap for how much gas is let through to cycle the action?
Since Amphibian will be using an adjustable gas block should the buffer test results apply pretty well to a fixed one also? |
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I'm new to the issue of adjusting gas to tweak how an AR runs. In a fixed non-adjustable gas block (like in my spikes uppers) is there a number or default gap for how much gas is let through to cycle the action? Since Amphibian will be using an adjustable gas block should the buffer test results apply pretty well to a fixed one also? So in the case of a MK18, the milspec port size for that barrel is .070. DD was selling barrels that were ported around .082 so people could run shit ammo through them and not send them back. I have one position set to .070" to be milspec. Another port for .049" for suppressor usage and another port for .082" for adverse...matching the port in the barrel. For this test, this is all kind of irrelevant. I was just throwing it out there as DD 10.3" MK18 barrels are notorious for being overgassed but I will be running it with my gas block and bringing the port size down to milspec....so basically just clarifying to everyone that while I will be using the DD 10.3" MK18 barrel I have a milspec port being used....so don't really think about it being an adjustable gas block as I won't be using the adjustable function. |
| I just ran my new L.A.R.B. on Saturday. All parts were new. DD 10.3, Sionics FA carrier, LMT enhanced bolt, Sprinco blue, LMT tube, SF 3P. I shot 200rnds of Fiocchi 55gr. .223. Compared to my normal Sprinco blue and H2, the L.A.R.B. ran great. Very smooth with very minimal dot bounce. Keep in mind that I also changed the L.A.R.B from 4 ounces to 5 ounces. All my brass ended up directly behind me due to the wall I had to my right at the indoor range. All the brass hit just the tip of the shell deflector. Not sure this matters. My guess is I'm a little heavy. As soon as I get back from Vegas I'm going to go back to the 4 ounces and also bring a Sprinco white to the range. I'm actually happier with this product more than I thought I'd be. I'll bring some 193 with me as well and use my RC2. Rifle runs nice. I am pleased. |
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Quoted:
Yeah, I know you have posted this a few times and I just think this isn't quantitative enough as it has the human factor involved....and every human is different....I'm not saying I won't do this type of thing as I've done it in the past but I just personally feel that the data from doing that kind of testing is the least objective. I would rank it this way in regards to objectivity: 1. full auto cyclic rate - again, not a determining factor in smoothness but it is a good data point, repeatable and no human influence. 2. accelerometer data - again, will be great...in theory...need to actually do some testing with it, should be repeatable and no human influence 3. hi speed camera video - will be very informative to see how the varying systems do in action, repeatable and no human influence 4. full auto dispersion testing, may or may not be repeatable and has the greatest amount of human influence Quoted:
Quoted: Personally, I'd like to see all buffers (H2; H2 w/ EAB and LARB Tip; DPM; LARB; Hydraulic buffer) all tested with the same Tubb flatwire. That way there's no extra variable of different springs to account for. As far as testing goes, one thing that might be interesting / show the overall effectiveness, is a full auto burst dispersion test between the systems. Say, a torso sized target at 15-25yds, with a 8" shoot n see target in the center to focus the sights on. When you do the 10rd mag dump, you also try and track the 8" target through the sights. The 'pattern' of the various 10rd bursts will help show overall controllability of the system; the tighter / more accurate the 10rd burst, likely the better/smoother/easier to track the sights with. Tighter/more accurate burst fire is the goal of the Ultimax, for example. This could be especially helpful in distinguishing buffers with otherwise comparable RPM's. Example, if the H2 buffer runs 850rpm, and the H2+EAB tip also runs 850rpm - but the EAB produces a noticeably tighter burst dispersion - that will show that the EAB is reducing overall weapon vibration even if it isn't lowering RPM. Example: https://www.recoilweb.com/wp-content/uploads/2018/03/Surefire_OBC01.jpg I would rank it this way in regards to objectivity: 1. full auto cyclic rate - again, not a determining factor in smoothness but it is a good data point, repeatable and no human influence. 2. accelerometer data - again, will be great...in theory...need to actually do some testing with it, should be repeatable and no human influence 3. hi speed camera video - will be very informative to see how the varying systems do in action, repeatable and no human influence 4. full auto dispersion testing, may or may not be repeatable and has the greatest amount of human influence Mostly, its that dispersion data most speaks to the end goal of these rate/impact reduction mods - improving controllability and reducing shot dispersion. So if it's possible, it would be a cool extra data point. |
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You had quite the reputation here. Looked like a very neat product. Mind sharing w/ us why you got out of the business? Quoted:
Quoted: When I was in business selling my MicroMOA Govnah... I've had some companies approach me about taking it over but when I explain to them the customization aspect of it and how different components will affect your port sizing and the knowledge required to support the product they don't want to deal with it. |
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amphibian, reading your post, I can appreciate what you must have gone though. I have seen other small businesses that have launched products, and a few individuals would run the vendor ragged with questions and requests for measurements, and then complaints and issues when they tried to adapt the product to some obscure, non-standard application. All for a $100 order, or even way less. No wonder companies might not follow through on introducing new products. These problem buyers wind up stifling innovation by their nitpicking.
In your case, taking care of family is the first priority, so you had to do what you had to, and you did the right thing. Back to these buffers, I like the idea of these bumpers to reduce felt impact, but as you mentioned, with all the variables of ammo type, gas port size, barrel length, etc. , everyone has to understand that this a pretty specific application. If you want one size fits all, get a rifle with a modestly oversized gas port, standard buffer, and deal with it. Adding one of these bumpers can help, but once you start to refine it for minimal recoil/max controllability, you have to consider every variable, and so you'll have more of a fair-weather range gun than a do-anything rifle. We're still talking 5.56 here, which, at it's worst, had pretty mild recoil. |
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Back to these buffers, I like the idea of these bumpers to reduce felt impact, but as you mentioned, with all the variables of ammo type, gas port size, barrel length, etc. , everyone has to understand that this a pretty specific application. If you want one size fits all, get a rifle with a modestly oversized gas port, standard buffer, and deal with it. Adding one of these bumpers can help, but once you start to refine it for minimal recoil/max controllability, you have to consider every variable, and so you'll have more of a fair-weather range gun than a do-anything rifle. We're still talking 5.56 here, which, at it's worst, had pretty mild recoil. For example a Tubb's flat wire spring/Kynshot RB5005 .308 hydraulic buffer run equally well for my CMMG Banshee RDB 9mm, Spike's Compressor 5.56 and .300 suppressed uppers, all on a Spike's Cal-Multi lower. I can swap quickly any of the 3 uppers and go to town with no other changes. The only caliber that doesn't run slow/smooth as I like is .300 supers (too fast for me at 900 and bouncy). Everything else is smooth as silk and in the 600's. I didn't have to tweak anything other than minor variations of a recipe set out by Amphibian. Having a mil-spec non-adjustable gas block eliminated one variable I didn't have to consider. The testing of the spring loaded buffers vs hydraulic and testing the tailcap bumpers is just icing on the cake that is already baked. Sounds like a lot of options to play with but the result of the the tests will be a short list of components effective for just about any build. Maybe not a direct hit but pretty darn close to a do-anything rifle build recipe. |
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Quoted:. My father was slowly dying at the time (he passed a couple years ago). I also had to take legal guardianship of my mom (which I still have to deal with). Also have a wife and two kids to look after. Plus a full time non-firearm related real job. I didn't pay myself running the business for over 2 years. All profits put back into the company and extremely time consuming. Answering so many questions (almost all were already documented on the website but rarely would anyone read it). Being so busy with family issues and my real job, it got to the point I was hoping I didn't have orders to deal with when I got home from work. I also started to dread going to the range to test things. I like to tinker but I felt like I had to tinker with things I didn't really care about messing with. I've had some companies approach me about taking it over but when I explain to them the customization aspect of it and how different components will affect your port sizing and the knowledge required to support the product they don't want to deal with it. |
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Quoted: Sorry you lost your Da and have to take care of your mother. Completely understandable you got out of the business. Do you have patents on your design? Have you considered open sourcing the TDP? |
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I received the Ammolytics Accelerometer (tweaked to 900 Hz) from Eric at Ammolytics and the printed enclosure arrived today from the designer. The device header pins are in the way so I'll have to alter the sled to make more room to avoid bending the pins. I'll install a power button and a charging cable extension this weekend and test the battery to see how long it will last during testing. If it runs down too fast I have a larger capacity battery that I can attach to the outside of the enclosure.
Everything else is ready to go. Thanks everyone for being patient while I get our ducks in a row. Attached File |
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I received the Ammolytics Accelerometer (tweaked to 900 Hz) from Eric at Ammolytics and the printed enclosure arrived today from the designer. The device header pins are in the way so I'll have to alter the sled to make more room to avoid bending the pins. I'll install a power button and a charging cable extension this weekend and test the battery to see how long it will last during testing. If it runs down too fast I have a larger capacity battery that I can attach to the outside of the enclosure. Everything else is ready to go. Thanks everyone for being patient while I get our ducks in a row. https://www.AR15.Com/media/mediaFiles/374164/IMG_20191108_161337_jpg-1153874.JPG  I can't wait to see the results.
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Quoted:
I received the Ammolytics Accelerometer (tweaked to 900 Hz) from Eric at Ammolytics and the printed enclosure arrived today from the designer. The device header pins are in the way so I'll have to alter the sled to make more room to avoid bending the pins. I'll install a power button and a charging cable extension this weekend and test the battery to see how long it will last during testing. If it runs down too fast I have a larger capacity battery that I can attach to the outside of the enclosure. Everything else is ready to go. Thanks everyone for being patient while I get our ducks in a row. https://www.AR15.Com/media/mediaFiles/374164/IMG_20191108_161337_jpg-1153874.JPG |
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Quoted: Great work man, thanks for all the effort you've made on getting this project together! |
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Yes! Looking forward to this. IMO, buffer and spring optimization is one of the last areas of the AR15/M16 platform where actual innovation and improvement is possible, and not just rehashing the same old shit with a slightly different twist. DI wise especially in the MIL, increase in parts wear from sunning suppressed 100% time is known. I have been running hydraulic buffers for years and FERFRANS bolt carrier that slows down rate of fire. Kynshot buffers are stiff but do work, I think between modify bolt carrier and changing up recoil system yes something should be done to get beyond the standard spring and buffer. Full auto is not used because of lack of control, change it so it can be controlled it is a effective method of engagement FERFRANS test 2008ish:  Jeff Gurwitch Tests Ferfrans Specialties RRS/DSAS in Adams Arms Tactical Piston AR SBR/PDW Adjusting gas on DI  Shooting a Tactical AR with the BPM Accu-Set Adjustable Gas System! |
[ARCHIVED THREAD] - DPM Recoil Reduction System vs. Hydraulic buffer EDIT: Armament LARB Mod 2 and 3 added to the test. (Page 2 of 4)
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