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Originally Posted By jt526: Anyone pull the barrel and have pictures? Originally Posted By jt526: Anyone pull the barrel and have pictures? I need to get a MP5-SD integral barrel mounted to this thing, and was hoping it was more of a "turn some threads on a regular barrel for the roller extension" and not a "machine all kinds of weirdo interlocking parts" kind of thing. i have the integral SD on a CMMG RDB build and have one on blowback that I was hoping to move to this upper. maybe I'll pull my barrel this weekend. |
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Originally Posted By tt350z: Finally got to try out a CMMG radial delayed gun today. One of the guy I shoot with had a Banshee that basically wouldnt eject. I told him I'd take a look at it and found that his ejector only had like #3 of pressure. I pulled the ejector spring out and it was considerably shorter than a new spring. He said he only had like 300 rounds through that spring since he replaced the original spring for ejection issues. The MEAN Arms blows the CMMG out of the water in all shooting attributes. It is way softer, flatter, and way more consistent ejection. The only thing the CMMG has the MEAN Arms best is cost, but I am so glad that I spent the extra money on the MEAN Arms. I have stated many times that I was never impressed with the out of the box recoil impulse of the CMMG Banshee or Dissent. Better than straight blowback but like 60% there compared to straight blowback but a tuned CMMG RDB can match the MP5 with a 'better' cyclic rate than the MP5. Most people running CMMG's Banshee's don't care about tuning until they start to fail and most don't know what smooth is as they haven't shot anything better side by side. The CMMG Dissent fixes the failing ejector spring problems since they finally went with a fixed ejector eliminating that from the maintenance schedule and point of failure. I would be ecstatic if MEAN did the same. Read the MEAN manual which clearly calls out wear item parts, like the ejector spring, ejector retention pin, extractor spring as well as the ball bearings. Nothing lasts for ever and it is to be expected for any delayed system where parts are impinging on each other. My tuned hybrid Dissent has not missed a beat since I built it which uses a fixed ejector. I run this full auto and suppressed with a tuneable full auto cyclic rate. The CMMG delay comes from the angled lugs on the bolt and the lugs in the barrel extension which are standard. Several people have made their own CMMG compatible barrels including myself. I have a custom stainless CMMG RDB barrel with over 50K rounds on it and there is no detectable wear on the extension and if there was some, I could swap it. You can buy spare bolts and BCG's from CMMG. Can't say the same for MEAN yet but yes, you can buy the lifters. Extra barrels are not yet available for the MEAN and now look at all the proprietary parts in the BCG for the MEAN. I would say my MEAN with the K lifter is slightly softer than my tuned hybrid CMMG Dissent but the ejector I have in there is fixed and will never fail and doesn't have a maintenance schedule that is clearly an advantage over the MEAN. For me my order of preference 'today' is: 1. My tuned hybrid CMMG Dissent with the fixed ejector and custom made carrier extension for tuning w/ buffers and springs as well as to trip the auto sear documented here: https://c3junkie.com/?page_id=1733 2. MEAN Arms is only second since it still uses an ejector spring that is inline with the recoil impulse and I'm already on my 3rd one in under 2000 rounds. 3. CMMG Banshee and deal with the ejector spring failures as well. Now if we are talking semi auto only and not full auto like I want my preference would probably be for someone that didn't want to go with any custom parts 1. JP-5 2. CMMG Dissent - I would move that to #1 if you are OK with custom parts or if you have a SBR lower since the JP-5 is using a proprietary upper/lower receiver length. ETA...At last month's SMG match, I ran my hybrid CMMG Dissent which ran 100%. 2 guys brought their MEAN uppers. Both had around 300 rounds on them before the match. 1 guy ran his for only 1 stage with no issues. The other guy ran all 4 stages with his MEAN and it was a disaster. I was the RO for him and saw several times where he had a live round facing back at him which was really weird as well as some FTE's. |
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Originally Posted By amphibian: I did...look at the previous page of this thread: https://www.ar15.com/forums/industry/Bearing-Delay-Upper-Receiver-Assembly-updates-information-and-resources/817-303326/&page=4 You would have to ask MEAN if they will sell you a spare barrel or extension but doubt it. Your end goal is do an SD build but they are already working with I think https://hitecarms.com on a SD setup. So they may want to do their own internal testing first. that plan works for me, time to sell off all the other crap I've accumulated for these builds. |
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Originally Posted By jt526: Well hell amphibian!!! Thanks, I had no idea there was an integral coming out. Looks like all I need is some patience and to shoot the CMMG until the extractor fails and then buy another mean arms uppers. Originally Posted By jt526: Well hell amphibian!!! Thanks, I had no idea there was an integral coming out. Looks like all I need is some patience and to shoot the CMMG until the extractor fails and then buy another mean arms uppers. and again, the MEAN isn't immune either. I'm on my 3rd EJECTOR SPRING on my MEAN in less than 2000 rounds of full auto / suppressed. My hybrid Dissent build utilizes a fixed ejector which removes that point of failure. that plan works for me, time to sell off all the other crap I've accumulated for these builds. |
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Joined:
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GA, USA
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This past weekend Zack Smith won the PCC division at the Rio Salado 33rd Annual Spring Steel using the Bearing Delay system! |
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Originally Posted By amphibian: CMMG's typically don't have EXTRACTOR failures...it is the EJECTOR SPRING that fails.... and again, the MEAN isn't immune either. I'm on my 3rd EJECTOR SPRING on my MEAN in less than 2000 rounds of full auto / suppressed. My hybrid Dissent build utilizes a fixed ejector which removes that point of failure. I believe you are running full auto suppressed with a RLL? I would wait till you have several thousand rounds through your MEAN before buying more...although, I'd be happy to sell you my MEAN upper if you want. I appreciate your dedication Amphibian. You saved me a lot of headache and heartache, by explaining the short falls of both the Mean and CMMG RDB systems. I'm looking forward to your completed write up on your custom Dissent and will probably go that direction if it is possible for me. Right now I'm really liking my 90% set up with the 9mm RDB bolt and barrel, Tubbs 300blk flat wire spring, and 5007 Hydraulic buffer. I allowed my wife to shoot it so she could compare it to her blowback AR-V and she didn't want to give me my weapon back. It was really a night and day difference. |
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Shot the local steel challenge match in PCC optic division with the Mean upper. There were 64 shooters and the top ten overall were dominated by the 22LR classes. Including my 10th place finish in rimfire rifle optic class. At 73 I don't expect to beat those way younger. However, with the Mean I was able to take 11th place only slightly slower than my 22LR performance. Used the Endomags downloaded to 28 rounds with no problems. I have abandoned using Glock mags at the local subgun match. Just don't get reliability when it was not engineered for Glock. 28 rounds would put me at a disadvantage against higher capacity guns so I am waiting for the 40 round Exomags. After testing I will post my results. After a lot of back and forth with Amphibian on his current CMMG project I have decided to stick with my Mean upper. His ability to re-engineer has me in awe but I think we have different goals in what we want from FA fire as I do not shoot suppressed for example. |
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Originally Posted By subgunner: Shot the local steel challenge match in PCC optic division with the Mean upper. There were 64 shooters and the top ten overall were dominated by the 22LR classes. Including my 10th place finish in rimfire rifle optic class. At 73 I don't expect to beat those way younger. However, with the Mean I was able to take 11th place only slightly slower than my 22LR performance. Used the Endomags downloaded to 28 rounds with no problems. I have abandoned using Glock mags at the local subgun match. Just don't get reliability when it was not engineered for Glock. 28 rounds would put me at a disadvantage against higher capacity guns so I am waiting for the 40 round Exomags. After testing I will post my results. After a lot of back and forth with Amphibian on his current CMMG project I have decided to stick with my Mean upper. His ability to re-engineer has me in awe but I think we have different goals in what we want from FA fire as I do not shoot suppressed for example. |
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There was a slight chance the 40 round Exomags would arrive in time for our monthly Subgun match tomorrow June 9th. That is not the case as I was informed some additional tweaks need to be made to the molds so there will be an additional delay. With the extreme high temperatures in the Nevada desert our monthly Subgun match is suspended for the months of July and August. Hoping that I will have the 40 round Exomags in time for the September match. It seems I missed the pre-order deadline to qualify to have my Exomag order doubled. Would have placed it earlier if I had known. |
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Originally Posted By tortilla-flats: @tt350z @amphibian @subgunner Any updates on your MEAN experience? I am not the only one either, I know two other people with the same issues. However we are all running full auto if that makes a difference. Now if they release a 'Gen2' with a fixed ejector, I would give it a try as it was smooth when it worked. |
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@tortilla-flats Still running perfectly. Zero malfunctions. Zero parts replaced. It’s been loaned to new shooters so they have something to compete with. Maintenance has just been some lube once in a while. I haven’t wiped down the BCG in like 2k rounds. Mines only used for USPSA/multi-gun. No full auto or suppressed. |
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Originally Posted By tt350z: @tortilla-flats Still running perfectly. Zero malfunctions. Zero parts replaced. It’s been loaned to new shooters so they have something to compete with. Maintenance has just been some lube once in a while. I haven’t wiped down the BCG in like 2k rounds. Mines only used for USPSA/multi-gun. No full auto or suppressed. Which upper are you using? Could you put a link in for slow types like me 
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Originally Posted By towerofpower94: Which upper are you using? Could you put a link in for slow types like me @towerofpower94 MEAN Arms bearing delay upper |
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Originally Posted By tt350z: Originally Posted By towerofpower94: Which upper are you using? Could you put a link in for slow types like me @towerofpower94 MEAN Arms bearing delay upper Thank you, sir |
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Originally Posted By amphibian: I sold mine with a $500 loss. If I had known they were going to release the production model with the same spring loaded ejector as the CMMG Banshee I wouldn't have gotten it. The earlier prototype that they had at a previous Shot Shot didn't use the same spring loaded ejector like the production model and was hoping that it would be that way. I should have waited to see what it really looked like. I did give it a chance though and after swapping ejector spring 3 times in under 1200 rounds, I was done. I am not the only one either, I know two other people with the same issues. However we are all running full auto if that makes a difference. Now if they release a 'Gen2' with a fixed ejector, I would give it a try as it was smooth when it worked. Originally Posted By amphibian: Originally Posted By tortilla-flats: @tt350z @amphibian @subgunner Any updates on your MEAN experience? I am not the only one either, I know two other people with the same issues. However we are all running full auto if that makes a difference. Now if they release a 'Gen2' with a fixed ejector, I would give it a try as it was smooth when it worked. Ive bern running a forced reset trigger on mine and have well over 2000 rounds with no issues. |
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And Hitec integral uppers are out. Order placed, they went fast, the email I got from them a while ago said 4 units, they are out of stock now. I am about 11 miles from them, so shipping out to be pretty fast! Now to sell my other one on EE. |
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Originally Posted By jt526: And Hitec integral uppers are out. Order placed, they went fast, the email I got from them a while ago said 4 units, they are out of stock now. I am about 11 miles from them, so shipping out to be pretty fast! Now to sell my other one on EE. What suppressor did you go with? The 9" or 12" |
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Originally Posted By jt526: I am using my 12" B&T suppressor for now. Honestly I need to get back to it. I think it is gumming up so fast from blowback is basically stops working pretty quickly. At least that is what I think is going on. Will report back. How do you attach it?? Is there a HUB barrel mount?? I thought it would take proprietary silencers?? |
| Oh, is it an MP5-SD can, so it is made to go on the integral barrel. I have the mean arms integral, a broad river tactical integral RDB setup, and an in lead we trust integral barrel for the MPX that I use the same can on until I get another SD can. However, Broad river tactical is releasing an mp-SD HUB adapter at some point so I'll pick up one of those to use on a sico hybrid I have literally never shot once in like 5 years. |
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Tested the 40 round Exomag with my RDIAS. Ran perfectly at 1570rpm with a reduced power buffer spring and H2 buffer. Would like to reduce the ROF so will be experimenting. Have been shooting in our steel match in PCCO the last four times. Been running flawlessly with the Endo’s downloaded to 28. Been changing mags after 3 runs but with the new Exo’s that won’t happen. Last match was 6th overall out of 62 shooters my best finish so far. |
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Shooting in sanctioned steel match with the Mean 7.5 inch upper and can duplicate times using my rimfire rifle. The match has five of the stages so in theory only required 125 rounds if you are clean. After 5 shoots no malfunctions. Used the 40 round mag in the last match without any issues. In the subgun match I have been waiting for the 40 round mag to be competitive. With my RDIAS the stock K lifter with 7.5 inch upper standard spring and H2 buffer RPM was 1571. Called Mean and they recommended the M lifter. That reduced RPM to 800. That is a good rate for our match. Will try it in the upcoming April shoot. Have also experimented with my Colt 9mm 6 inch upper. My setup has been hydraulic buffer from Brownells with a light spring and RPM is 1430 a bit too high. Using the Just right carbine tube which is 8.5 inches long, light spring, 2 kynshot 2.5 ounce weights and Kynshot 5000 buffer ROF was 640 RPM. However was getting failures to eject. Think bolt speed is too slow. This is an absolute pussycat semi! Less felt recoil than the Mean upper with the M lifter. May need to swap back to K for semi. Fashioned a weight from aluminum to replace one of the Kynshot weights. Weight is 1 ounce compared to 2.5 ounce so should increase the ROF. Will see if it fixes the ejection. |
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Originally Posted By subgunner:... Have also experimented with my Colt 9mm 6 inch upper. My setup has been hydraulic buffer from Brownells with a light spring and RPM is 1430 a bit too high. Using the Just right carbine tube which is 8.5 inches long, light spring, 2 kynshot 2.5 ounce weights and Kynshot 5000 buffer ROF was 640 RPM. However was getting failures to eject. Think bolt speed is too slow. This is an absolute pussycat semi! Less felt recoil than the Mean upper with the M lifter. May need to swap back to K for semi. Fashioned a weight from aluminum to replace one of the Kynshot weights. Weight is 1 ounce compared to 2.5 ounce so should increase the ROF. Will see if it fixes the ejection. As a point of comparison to the above portion of the post: For 9mm M16 shooting I have a direct blowback AR pattern, no LRBHO trip upper with a 5.5 in. 9mm barrel, without silencer. I use a 9mm, small extractor BCG with a KAK Industry tungsten weight replacement for the standard steel BCG weight and the final BCG weight is 17.1 oz. I use a B&T AR9 hydraulic buffer (~6.1 oz.) and a standard recoil spring in a standard, carbine length buffer tube. Total reciprocating weight is about 23.2 oz. Using Federal AE 115 gr. 9mm ammo, the average full auto ROF is 655 RPM. No issues with extraction or ejection. MHO, YMMV, etc. ETA: With the JRC (8.5 in.) buffer tube the two added spacer weights "stack" (i.e., pre-load) the recoil spring by 1.5 in., so a bit of experimentation (e.g., softer and/or flat wire recoil spring) might be needed to get proper cycling while still getting reliable feeding, especially when using Glock or other single feed mags versus Colt/Uzi double feed mags. MHO, YMMV, etc. |
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Originally Posted By subgunner: Tested the 40 round Exomag with my RDIAS. Ran perfectly at 1570rpm with a reduced power buffer spring and H2 buffer. Would like to reduce the ROF so will be experimenting. Have been shooting in our steel match in PCCO the last four times. Been running flawlessly with the Endo’s downloaded to 28. Been changing mags after 3 runs but with the new Exo’s that won’t happen. Last match was 6th overall out of 62 shooters my best finish so far. Any chance you're willing to upload a video with the 2 lifters? Nearly 1600 rpm is wild. Useless practically, but undeniably a giggle. |
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No longer experimenting with the Mean upper Full Auto. Ran one subgun match with the Exomags and did OK. Gone back to my Colt blowback using a Just Right Carbine buffer tube with a 5000 Kynshot buffer and one Kynshot spacer weight with a flat spring. This set up is a pussycat running at 650 rpm. Colt mags are easy to load and make mag changes. Also can use a Beta in our unlimited class. So have the Mean upper dedicated to the steel match. In theory 25 rounds per stage so the original mags can work but like having the Exomag loaded to 35 so no chance of running out. Some kind of loader would be nice to save the fingers. |