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Posted: 5/19/2024 7:25:10 AM EST
[#1]
Anyone knowlegable on rollers, the part used to engage with the feed lever?
Some historical designs do not use a roller at all, such is the 1919 and M2HB. There is a feed lever that rides in a track and has no rolling surface, it just rides in there with full friction. Presumably this is a lubrication point requiring grease or oil. But many other designs have an actual roller, such as the m60, m240, and Stoner 63. Does anyone know what type of roller is used? Is it a ball bearing, roller bearing, or something else? |
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Posted: 5/19/2024 9:49:06 AM EST
[Last Edit: sgthatred]
[#2]
The Stoner 63a uses a roller on a shaft, no bearing material. The M60 is the same.
Something you are going to need to take into account is how to get the feed track to line up with the roller when you close the cover. M60 and the Stoner 63 both had to have the bolt group back on the sear for the top cover to be closed. The Stoner 63A corrected this by making the roller so it is spring loaded in the vertical direction so if the top cover is closed with the bolt group forward the roller was depressed and would engage the feed track when bolt group was retracted to the rear. The M60 eventually did the same thing. Stoner 63a spring roller  Attached FileStoner 63 non sprung roller.  Attached File |
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Posted: 5/19/2024 10:46:00 AM EST
[Last Edit: Type7SOT]
[#3]
Quote HistoryOriginally Posted By sgthatred: The Stoner 63a uses a roller on a shaft, no bearing material. The M60 is the same. Something you are going to need to take into account is how to get the feed track to line up with the roller when you close the cover. M60 and the Stoner 63 both had to have the bolt group back on the sear for the top cover to be closed. The Stoner 63A corrected this by making the roller so it is spring loaded in the vertical direction so if the top cover is closed with the bolt group forward the roller was depressed and would engage the feed track when bolt group was retracted to the rear. The M60 eventually did the same thing. Stoner 63a spring roller https://www.ar15.com/media/mediaFiles/220681/bc-4_jpg-3218116.JPG Stoner 63 non sprung roller. https://www.ar15.com/media/mediaFiles/220681/P1010068_jpg-3218121.JPG Thats really helpful, thanks. I'm a manufacturing engineer, but not a mechancal engineer. I'm having a hard time understanding how a roller around a shaft with no ball bearings or roller bearings actually reduces friction by any significant amount. With this design you still have metal rubbing on metal, its just happening internally instead of externally. I suppose to gives you a consolidated place to hold lubricant, rather than needing to lube the entire track of the feed lever. It also may wear better, because it will wear radially instead of a flat spot. I can get a sealed press-on ball bearing for $6 which handles an 80lb lateral load and 63,000 rpm. I'm debating between this and just a plain old round post. If the 1919 can get away without having a roller, maybe a post will work fine. Sometimes simple is better, less parts to break, right? The roller is one of the cheapest parts of the assembly, so not a big deal to experiment with different options and see what works best. |
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Posted: 5/19/2024 11:25:29 AM EST
[#4]
Quote HistoryOriginally Posted By Type7SOT: Thats really helpful, thanks. I'm a manufacturing engineer, but not a mechancal engineer. I'm having a hard time understanding how a roller around a shaft with no ball bearings or roller bearings actually reduces friction by any significant amount. With this design you still have metal rubbing on metal, its just happening internally instead of externally. I suppose to gives you a consolidated place to hold lubricant, rather than needing to lube the entire track of the feed lever. It also may wear better, because it will wear radially instead of a flat spot. I can get a sealed press-on ball bearing for $6 which handles an 80lb lateral load and 63,000 rpm. I'm debating between this and just a plain old round post. If the 1919 can get away without having a roller, maybe a post will work fine. Sometimes simple is better, less parts to break, right? The roller is one of the cheapest parts of the assembly, so not a big deal to experiment with different options and see what works best. Quote HistoryOriginally Posted By Type7SOT: Originally Posted By sgthatred: The Stoner 63a uses a roller on a shaft, no bearing material. The M60 is the same. Something you are going to need to take into account is how to get the feed track to line up with the roller when you close the cover. M60 and the Stoner 63 both had to have the bolt group back on the sear for the top cover to be closed. The Stoner 63A corrected this by making the roller so it is spring loaded in the vertical direction so if the top cover is closed with the bolt group forward the roller was depressed and would engage the feed track when bolt group was retracted to the rear. The M60 eventually did the same thing. Stoner 63a spring roller https://www.ar15.com/media/mediaFiles/220681/bc-4_jpg-3218116.JPG Stoner 63 non sprung roller. https://www.ar15.com/media/mediaFiles/220681/P1010068_jpg-3218121.JPG Thats really helpful, thanks. I'm a manufacturing engineer, but not a mechancal engineer. I'm having a hard time understanding how a roller around a shaft with no ball bearings or roller bearings actually reduces friction by any significant amount. With this design you still have metal rubbing on metal, its just happening internally instead of externally. I suppose to gives you a consolidated place to hold lubricant, rather than needing to lube the entire track of the feed lever. It also may wear better, because it will wear radially instead of a flat spot. I can get a sealed press-on ball bearing for $6 which handles an 80lb lateral load and 63,000 rpm. I'm debating between this and just a plain old round post. If the 1919 can get away without having a roller, maybe a post will work fine. Sometimes simple is better, less parts to break, right? The roller is one of the cheapest parts of the assembly, so not a big deal to experiment with different options and see what works best. Maybe instead of a single track w/ a single roller, a wider track w/ two smaller rollers that are independent & take a load only on one side or t'other? Then they'd actually roll. |
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Posted: 5/19/2024 11:29:46 AM EST
[#5]
Quote HistoryOriginally Posted By backbencher: Maybe instead of a single track w/ a single roller, a wider track w/ two smaller rollers that are independent & take a load only on one side or t'other? Then they'd actually roll. A single roller will still roll in both directions, because its sized approx .010" smaller than the track. It will be biased on one side of the track for the rearward travel, and the opposite side for the forward travel. |
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Posted: 5/19/2024 11:55:55 AM EST
[#6]
BRP uses a roller bearing type roller on their semi bolt conversions for the MG-42:
https://www.brpguns.com/mg42-semi-auto-bolt-roller-support-shim-and-screw/ I've been looking at the roller part a bit lately as I'm going to have to redesign that part for the one I'm building. One option on the table is an M-14 bolt roller type, or possibly just a solid stud. The NIW MG-42 bolts I have are swaged tight enough they don't rotate at all, but some of the older ones I have are loose enough to turn. The later, heavy MG-3 bolt didn't rotate but had a spring loaded feature that made closing the cover. I think the later style MG3 covers had a spring to return the track to whichever side facilitates closing the cover as well. That's a feature I probably would not have thought of on my own. Here is a link to a listing for one of the later MG3 style spring loaded bolts (not mine): https://www.gunbroker.com/item/1046813946 Has some good pics of how the spring loaded bit works. |
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Posted: 5/19/2024 12:22:53 PM EST
[#7]
Quote HistoryOriginally Posted By BASE: BRP uses a roller bearing type roller on their semi bolt conversions for the MG-42: https://www.brpguns.com/mg42-semi-auto-bolt-roller-support-shim-and-screw/ I've been looking at the roller part a bit lately as I'm going to have to redesign that part for the one I'm building. One option on the table is an M-14 bolt roller type, or possibly just a solid stud. The NIW MG-42 bolts I have are swaged tight enough they don't rotate at all, but some of the older ones I have are loose enough to turn. The later, heavy MG-3 bolt didn't rotate but had a spring loaded feature that made closing the cover. I think the later style MG3 covers had a spring to return the track to whichever side facilitates closing the cover as well. That's a feature I probably would not have thought of on my own. Here is a link to a listing for one of the later MG3 style spring loaded bolts (not mine): https://www.gunbroker.com/item/1046813946 Has some good pics of how the spring loaded bit works. Excellent reference info. I'm really leaning towards the $6 press-on bearing. Its simple, should work great, its inexpensive, and replaceable. If it wears out after 20k rounds or something, just press it off and press on a new one with an arbor press. I'm thinking I might not bother with anything spring loaded, as its not actually needed and adds complexity. Again, the 1919 and M2HB dont have this feature, you just have to make sure the feed lever is in the right position before slamming the top cover. My goal is to make this as simple and inexensive as possible, while not sacrificing reliability. I care more about reliability than bells and whistles. |
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Posted: 5/19/2024 12:57:16 PM EST
[#8]
Quote HistoryOriginally Posted By Type7SOT: Excellent reference info. I'm really leaning towards the $6 press-on bearing. Its simple, should work great, its inexpensive, and replaceable. If it wears out after 20k rounds or something, just press it off and press on a new one with an arbor press. I'm thinking I might not bother with anything spring loaded, as its not actually needed and adds complexity. Again, the 1919 and M2HB dont have this feature, you just have to make sure the feed lever is in the right position before slamming the top cover. My goal is to make this as simple and inexensive as possible, while not sacrificing reliability. I care more about reliability than bells and whistles. Quote HistoryOriginally Posted By Type7SOT: Originally Posted By BASE: BRP uses a roller bearing type roller on their semi bolt conversions for the MG-42: https://www.brpguns.com/mg42-semi-auto-bolt-roller-support-shim-and-screw/ I've been looking at the roller part a bit lately as I'm going to have to redesign that part for the one I'm building. One option on the table is an M-14 bolt roller type, or possibly just a solid stud. The NIW MG-42 bolts I have are swaged tight enough they don't rotate at all, but some of the older ones I have are loose enough to turn. The later, heavy MG-3 bolt didn't rotate but had a spring loaded feature that made closing the cover. I think the later style MG3 covers had a spring to return the track to whichever side facilitates closing the cover as well. That's a feature I probably would not have thought of on my own. Here is a link to a listing for one of the later MG3 style spring loaded bolts (not mine): https://www.gunbroker.com/item/1046813946 Has some good pics of how the spring loaded bit works. Excellent reference info. I'm really leaning towards the $6 press-on bearing. Its simple, should work great, its inexpensive, and replaceable. If it wears out after 20k rounds or something, just press it off and press on a new one with an arbor press. I'm thinking I might not bother with anything spring loaded, as its not actually needed and adds complexity. Again, the 1919 and M2HB dont have this feature, you just have to make sure the feed lever is in the right position before slamming the top cover. My goal is to make this as simple and inexensive as possible, while not sacrificing reliability. I care more about reliability than bells and whistles. 1st time someone slams the feed cover down w/ that roller in the wrong position, will it still be reliable? 
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Posted: 5/19/2024 1:15:15 PM EST
[#9]
Quote HistoryOriginally Posted By backbencher: 1st time someone slams the feed cover down w/ that roller in the wrong position, will it still be reliable? I think it would take a lot of really HARD slams to actually break something. If you slam it down hard repeatedly in the wrong position, maybe you deserve to have something break lol. |
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Posted: 5/19/2024 1:17:33 PM EST
[#10]
Make it fit a MAC-10 or MAC-11 lower so machine guns can have belt fed caliber conversions.
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Posted: 5/19/2024 1:23:52 PM EST
[#11]
Quote HistoryOriginally Posted By cherenkov: Make it fit a MAC-10 or MAC-11 lower so machine guns can have belt fed caliber conversions. Thats step 3. I say step 3 because step 2 is a 308 version. Did I mention I have an m11/9? |
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MP, USA
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Posted: 5/19/2024 3:25:31 PM EST
[Last Edit: JoshNC]
[#12]
The HK 21, 21E, and 23E also use a spring loaded (vertically) plunger that interacts with the cam slot in the carrier. It is not a roller design, just a friction fit.
I’d be inclined to design this without a roller but spring loaded to allow the top cover to close regardless of bolt position. |
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Posted: 5/19/2024 4:48:01 PM EST
[#13]
The loads on the roller are very high. The feed cover is a very violent mechanical action. Closing the top cover on a bolt group in the wrong location has been the downfall of many a belt feed gun design. The Stoner 63 before they added the spring loaded roller tended to bend the top cover. Never underestimate the bigger idiot theory when designing.
Due to the high loads I use grease for a lubricant on the roller axle. Remember your roller will impart a large load into the carrier in a perpendicular direction to what a non belt fed carrier normally sees. Make sure you have bearing surface in the front and rear of the carrier or an aluminum upper will be worn out quickly. |
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CA, USA
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Posted: 5/19/2024 6:35:32 PM EST
[#14]
Quote HistoryOriginally Posted By Type7SOT: I'm a manufacturing engineer, but not a mechancal engineer. I'm having a hard time understanding how a roller around a shaft with no ball bearings or roller bearings actually reduces friction by any significant amount. With this design you still have metal rubbing on metal, its just happening internally instead of externally. I suppose to gives you a consolidated place to hold lubricant, rather than needing to lube the entire track of the feed lever. It also may wear better, because it will wear radially instead of a flat spot. You need to zoom out on the thinking here I think. The theoretical line of contact between the shaft and bearing, where the friction comes from, may (probably lower) be about the same as a cam pin and receiver, but look at what adding a rotating component to the system does. You create a moment that drastically decreases the applied force required to slide the bearing past the shaft (friction). Moments you can think of as leverage. Moments are described as force TIMES the perpendicular distance between the center of the arc and the force. This works because the bearing to receiver contact is not slipping (friction) but rotating about a line of contact. At least that's what come to mind as a possible answer. |
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Posted: 5/19/2024 11:30:13 PM EST
[#15]
Quote HistoryOriginally Posted By sgthatred: The loads on the roller are very high. The feed cover is a very violent mechanical action. Closing the top cover on a bolt group in the wrong location has been the downfall of many a belt feed gun design. The Stoner 63 before they added the spring loaded roller tended to bend the top cover. Never underestimate the bigger idiot theory when designing. Due to the high loads I use grease for a lubricant on the roller axle. Remember your roller will impart a large load into the carrier in a perpendicular direction to what a non belt fed carrier normally sees. Make sure you have bearing surface in the front and rear of the carrier or an aluminum upper will be worn out quickly. OP's making his own upper. OP could start w/ a 1" internal dia steel pipe? |
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Posted: 5/20/2024 4:26:04 PM EST
[#16]
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Posted: 5/20/2024 4:59:40 PM EST
[#17]
Neato. That's impressive.
What kind of printer are you using? Did you scrounge the feed mechanism parts from something else or did you make all of that as well? |
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Posted: 5/20/2024 6:40:21 PM EST
[Last Edit: Type7SOT]
[#18]
Quote HistoryOriginally Posted By BASE: Neato. That's impressive. What kind of printer are you using? Did you scrounge the feed mechanism parts from something else or did you make all of that as well? I'm using a Bambu Lab P1S and Polymaker PLA Pro filament. The feed paws are from an M249 saw. |
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NH, USA
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Posted: 5/21/2024 3:57:33 PM EST
[#19]
Wow, I for one, am very impressed. I bet adapting this to your M11/NINE would be very impressive.
Scott |
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Posted: 5/22/2024 3:17:27 PM EST
[#20]
Here is the mostly assembled 3D printed BCG:
 Attached FileWorks perfectly with the Brownells gas key staking tool:  Attached File |
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Posted: 5/25/2024 6:58:00 AM EST
[#21]
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Posted: 5/25/2024 7:03:53 AM EST
[#22]
Looks great. Subscribed to see how this turns out.
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Posted: 5/25/2024 7:17:51 AM EST
[#23]
Quote HistoryOriginally Posted By Type7SOT: Found a quad rail that works with the 90 degree gas tube configuration https://www.ar15.com/media/mediaFiles/490765/1000006175_jpg-3222844.JPG Gonna need some rail covers on the left side.
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Posted: 5/25/2024 7:35:30 AM EST
[#24]
Quote HistoryOriginally Posted By backbencher: Gonna need some rail covers on the left side. That is a potential concern. But thankfully the handguard has vents directly above the gas tube. Worst case, throw a vertical grip on there and get your hand away from the heat. |
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Posted: 5/28/2024 2:43:03 PM EST
[#25]
Quote HistoryOriginally Posted By Type7SOT: These are great suggestions, but most of these are not feasible with the constraints of an AR15 lower. This is why it makes much more sense to design a completely new belt-fed semi-auto rifle, rather than try and shoe-horn a "rigged up" belt-fed upper onto an AR-15 lower. Tony |
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Posted: 5/28/2024 3:36:51 PM EST
[#26]
Quote HistoryOriginally Posted By TonyRumore: This is why it makes much more sense to design a completely new belt-fed semi-auto rifle, rather than try and shoe-horn a "rigged up" belt-fed upper onto an AR-15 lower. Tony I respectfully disagree. If I had to design a gun from scratch, I would be dead before I had the first functioning prototype. I'm not Tony Stark lol. I need to start with a platform that is well understood, so I don't need to reinvent a million things (hammer, trigger, bolt, recoil assembly, etc etc. On that note, todays update: Got a new upper and top cover printed, and addressed a few issues. Barrel fits now, and it has the equivelant of an m4 feed ramp. The barrel locating pin notch is located such that a standard ar15 barrel works. Only mod needed is drilling a new gas port.  Attached File Attached File |
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Posted: 5/28/2024 3:38:57 PM EST
[#27]
Quote HistoryOriginally Posted By TonyRumore: This is why it makes much more sense to design a completely new belt-fed semi-auto rifle, rather than try and shoe-horn a "rigged up" belt-fed upper onto an AR-15 lower. Tony Quote HistoryOriginally Posted By TonyRumore: Originally Posted By Type7SOT: These are great suggestions, but most of these are not feasible with the constraints of an AR15 lower. This is why it makes much more sense to design a completely new belt-fed semi-auto rifle, rather than try and shoe-horn a "rigged up" belt-fed upper onto an AR-15 lower. Tony If you're an SOT and can wave your magic auto wand & poof, it's a demo concept for your local PD, sure. For us hoi polloi who have to spend $30k for an auto sear or spend all of $300 for a binary trigger, it damn well better work on an AR lower. |
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Posted: 5/29/2024 3:19:58 PM EST
[#28]
Quote HistoryOriginally Posted By sgthatred: The loads on the roller are very high. The feed cover is a very violent mechanical action. Closing the top cover on a bolt group in the wrong location has been the downfall of many a belt feed gun design. The Stoner 63 before they added the spring loaded roller tended to bend the top cover. Never underestimate the bigger idiot theory when designing. Due to the high loads I use grease for a lubricant on the roller axle. Remember your roller will impart a large load into the carrier in a perpendicular direction to what a non belt fed carrier normally sees. Make sure you have bearing surface in the front and rear of the carrier or an aluminum upper will be worn out quickly. The OP may not realize the wealth of knowledge and experience you bring to these forums. |
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Posted: 5/29/2024 4:18:56 PM EST
[#29]
Quote HistoryOriginally Posted By brazos609: The OP may not realize the wealth of knowledge and experience you bring to these forums. Not sure if that was supposed to be a dig at me, but I greatly appreciate his input as well as everyone else in this thread. Regarding the spring loaded plunger, I do plan to implement that design. I'm just not at that stage yet, my first step is to get a functional prototype, and refine it from there. |
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NH, USA
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Posted: 5/30/2024 9:20:33 PM EST
[#30]
From my perspective, for an overall firearm, certainly a clean slate build, would have fewer compromises. But who would buy it? I would think that quite a few of the buyers for a AR compatible belt fed upper would have some form of AR-15/M16 machinegun. Certainly that won't be all the sales, but I bet the majority would go to M16, DIAS, or Lightning Link owners. I am fortunate enough to own quite a few Beta-C drums. Over half of which I bought from semi auto owners that used their Beta-C a couple of times and sold it. The first one I bought, the first time I used it, I remember, somewhere around 85 or 90 rounds, thinking "I hope this thing runs out soon, my trigger finger is getting sore."
Being fortunate enough to own a DIAS, my various Valkyrie Armaments belt fed system configurations are piles of fun. But I don't know as I would really like to stand there and pull the trigger 200 times. To each his own. If that is your "jam" more power to you. I think that a 5.56X45 belt fed for the Mac style family of RRs would be fun and an untouched market. IMHO, beltfeds are pricy to buy, and even pricier to feed. Today machineguns are big money and belt fed machineguns are even bigger money. But at around $0.50 per round for 5.5.56X45, you best have big money to feed a beltfed. YMMV. Scott |
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Posted: 5/30/2024 9:35:50 PM EST
[Last Edit: Type7SOT]
[#31]
Quote HistoryOriginally Posted By canon3825: From my perspective, for an overall firearm, certainly a clean slate build, would have fewer compromises. But who would buy it? I would think that quite a few of the buyers for a AR compatible belt fed upper would have some form of AR-15/M16 machinegun. Certainly that won't be all the sales, but I bet the majority would go to M16, DIAS, or Lightning Link owners. I am fortunate enough to own quite a few Beta-C drums. Over half of which I bought from semi auto owners that used their Beta-C a couple of times and sold it. The first one I bought, the first time I used it, I remember, somewhere around 85 or 90 rounds, thinking "I hope this thing runs out soon, my trigger finger is getting sore." Being fortunate enough to own a DIAS, my various Valkyrie Armaments belt fed system configurations are piles of fun. But I don't know as I would really like to stand there and pull the trigger 200 times. To each his own. If that is your "jam" more power to you. I think that a 5.56X45 belt fed for the Mac style family of RRs would be fun and an untouched market. IMHO, beltfeds are pricy to buy, and even pricier to feed. Today machineguns are big money and belt fed machineguns are even bigger money. But at around $0.50 per round for 5.5.56X45, you best have big money to feed a beltfed. YMMV. Scott Thanks for your input. I think the main reason people dont buy belt feds is because they are too expensive, not because they are somehow useless in semi auto. Capacity is good, whether in full auto or semi. Look how popular various high cap mags are, whether 40, 60, or 100 rounds. Tons of people buy these mags and run them on semi auto. If a belt fed upper was the same price as a standard upper, I think everyone would have one. Oh, and they are just cool.  |
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Posted: 6/1/2024 11:53:13 AM EST
[#32]
Here is the extended firing pin:
 Attached FileIt has about 30% more mass than a standard firing pin because of the extension. However, if I make it out of titanium, then it will be lighter than a standard firing pin. I may go this route to avoid issues with accidental discharges due to the free floating design. Alternatively I could incorporate a biasing spring, but I started going down that path and it will require too many changes in the bolt carrier and bolt. Using a lighter material seems like the simplest approach (and titanium firing pins already have a proven track record). |
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Posted: 6/3/2024 12:57:08 PM EST
[Last Edit: backbencher]
[#33]
https://www.ar15.com/forums/armory/It-s-2-14-2024-where-s-the-Cryostructure-Shrike-clone-upper-/65-550065/#i6073262
 Attached FileThey also are using a longer receiver and bolt carrier. |
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Posted: 6/3/2024 2:55:17 PM EST
[#34]
Quote HistoryOriginally Posted By backbencher: https://www.ar15.com/forums/armory/It-s-2-14-2024-where-s-the-Cryostructure-Shrike-clone-upper-/65-550065/#i6073262 https://www.ar15.com/media/mediaFiles/203509/1000003374_jpg-3179338.JPG They also are using a longer receiver and bolt carrier. I dont believe so, I believe it appears longer because of the quick change barrel. Look at the top cover hinge, its lined up with the front takedown pin. On mine its 3/4" in front of it. Also, theirs work with magazines, so its unlikely that its stretched. |
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Posted: 6/3/2024 3:24:00 PM EST
[#35]
Quote HistoryOriginally Posted By Type7SOT: I dont believe so, I believe it appears longer because of the quick change barrel. Look at the top cover hinge, its lined up with the front takedown pin. On mine its 3/4" in front of it. Also, theirs work with magazines, so its unlikely that its stretched. Quote HistoryOriginally Posted By Type7SOT: Originally Posted By backbencher: https://www.ar15.com/forums/armory/It-s-2-14-2024-where-s-the-Cryostructure-Shrike-clone-upper-/65-550065/#i6073262 https://www.ar15.com/media/mediaFiles/203509/1000003374_jpg-3179338.JPG They also are using a longer receiver and bolt carrier. I dont believe so, I believe it appears longer because of the quick change barrel. Look at the top cover hinge, its lined up with the front takedown pin. On mine its 3/4" in front of it. Also, theirs work with magazines, so its unlikely that its stretched. Ahh. |
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NH, USA
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Posted: 6/4/2024 9:34:10 AM EST
[#36]
Quote HistoryOriginally Posted By Type7SOT: Thanks for your input. I think the main reason people dont buy belt feds is because they are too expensive, not because they are somehow useless in semi auto. Capacity is good, whether in full auto or semi. Look how popular various high cap mags are, whether 40, 60, or 100 rounds. Tons of people buy these mags and run them on semi auto. If a belt fed upper was the same price as a standard upper, I think everyone would have one. Oh, and they are just cool. Respectfully, I disagree, as I don't think that even if the belt fed was the same price, a belt fed is significantly heavier. Transitioning from target to target is slower. Running and gunning with a six or seven pound gun with a 30 round mag is easier and simpler than with a the same lower with a seven and a half pound upper plus the seven pounds of the 200 belt. Certainly a beltfed is very cool. As an owner of the Valkyrie Armaments beltfed system and a DIAS, I think a beltfed has far greater volume of fire than mags. But beyond the cost, a beltfed is just slower and heavier than a carbine with mags. Beyond that, a beltfed is a lot more money to buy. That is just the way it is. Lots more moving specialty parts to break or wear. There is also getting replacement parts. I love my Valkyrie system. The feed mech goes in the modified magwell of the AR lower. So as long as the AR upper is modified for the Valkyrie system, it can be used. I have a standard heavy barreled carbine upper, a MGI (Hydra) upper with three fluted heavy barrels using modified short stroke piston piston kits for heavier rates of fire, and a water cooled 20" heavy fluted barrel DI upper that has had 500 rounds through it with one pull. https://youtu.be/RFcxuOzsoXA?si=5ltNFpu6627CYbVo This video is my wife doing 500 rounds. I am the A gunner. But Valkyrie Armaments is no longer in business. Since I only have one feed mech, where would one go for parts? Personally, I have found that the greater the capacity of the mag, the price goes up exponentially. A 40 round Pmag is like 35% more than a 30 round Pmag. The 60 round Magpul is around $100 more than the 40 round Pmag. The Beta-C is around double the price of the 60 round Magpul. And the 150 Armatec ($433.67 plus shipping) is one and a half times the Beta-C. The Surefire 100 is hard to find but is cheaper and simpler than the Beta-C. Again, I think that this project is awesome. I certainly would love to buy one, if this becomes available. Please keep up the good work. I am so very envious. Scott |
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Posted: 6/4/2024 11:14:57 AM EST
[Last Edit: Type7SOT]
[#37]
Quote HistoryOriginally Posted By canon3825: Respectfully, I disagree, as I don't think that even if the belt fed was the same price, a belt fed is significantly heavier. Transitioning from target to target is slower. Running and gunning with a six or seven pound gun with a 30 round mag is easier and simpler than with a the same lower with a seven and a half pound upper plus the seven pounds of the 200 belt. Certainly a beltfed is very cool. As an owner of the Valkyrie Armaments beltfed system and a DIAS, I think a beltfed has far greater volume of fire than mags. But beyond the cost, a beltfed is just slower and heavier than a carbine with mags. Beyond that, a beltfed is a lot more money to buy. That is just the way it is. Lots more moving specialty parts to break or wear. There is also getting replacement parts. I love my Valkyrie system. The feed mech goes in the modified magwell of the AR lower. So as long as the AR upper is modified for the Valkyrie system, it can be used. I have a standard heavy barreled carbine upper, a MGI (Hydra) upper with three fluted heavy barrels using modified short stroke piston piston kits for heavier rates of fire, and a water cooled 20" heavy fluted barrel DI upper that has had 500 rounds through it with one pull. https://youtu.be/RFcxuOzsoXA?si=5ltNFpu6627CYbVo This video is my wife doing 500 rounds. I am the A gunner. But Valkyrie Armaments is no longer in business. Since I only have one feed mech, where would one go for parts? Personally, I have found that the greater the capacity of the mag, the price goes up exponentially. A 40 round Pmag is like 35% more than a 30 round Pmag. The 60 round Magpul is around $100 more than the 40 round Pmag. The Beta-C is around double the price of the 60 round Magpul. And the 150 Armatec ($433.67 plus shipping) is one and a half times the Beta-C. The Surefire 100 is hard to find but is cheaper and simpler than the Beta-C. Again, I think that this project is awesome. I certainly would love to buy one, if this becomes available. Please keep up the good work. I am so very envious. Scott Thank you sir. For me its more about the cool factor than anything else. I don't disagree with any of your points. As for replacement parts, I'm using as many standard parts as possible. So far, here is the list of standard parts: All feed paws, springs, and pins: M249 Barrel: AR15 (only need to drill new gas port, drilling jig can be made) Handguard: AR15 Gas block/tube/key: AR15 Small bolt parts (extractor/ejector etc) AR15 Cam pin: AR15 (modified) Top cover latch: AR15 (mag release) Charging handle: Any generic side charging handle for AR15 can work (or in a pinch, 10-32 shoulder bolt) Additionally, many of the pins and small parts are standard McMaster car parts. Sure, the main parts are custom made, but these parts are unlikely to be major wear items. It should be easy for someone to keep this upper in service even if I get hit by a truck. |
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Posted: 6/4/2024 12:01:22 PM EST
[#38]
Quote HistoryOriginally Posted By canon3825: Respectfully, I disagree, as I don't think that even if the belt fed was the same price, a belt fed is significantly heavier. Transitioning from target to target is slower. Running and gunning with a six or seven pound gun with a 30 round mag is easier and simpler than with a the same lower with a seven and a half pound upper plus the seven pounds of the 200 belt. Certainly a beltfed is very cool. As an owner of the Valkyrie Armaments beltfed system and a DIAS, I think a beltfed has far greater volume of fire than mags. But beyond the cost, a beltfed is just slower and heavier than a carbine with mags. Beyond that, a beltfed is a lot more money to buy. That is just the way it is. Lots more moving specialty parts to break or wear. There is also getting replacement parts. I love my Valkyrie system. The feed mech goes in the modified magwell of the AR lower. So as long as the AR upper is modified for the Valkyrie system, it can be used. I have a standard heavy barreled carbine upper, a MGI (Hydra) upper with three fluted heavy barrels using modified short stroke piston piston kits for heavier rates of fire, and a water cooled 20" heavy fluted barrel DI upper that has had 500 rounds through it with one pull. https://youtu.be/RFcxuOzsoXA?si=5ltNFpu6627CYbVo This video is my wife doing 500 rounds. I am the A gunner. But Valkyrie Armaments is no longer in business. Since I only have one feed mech, where would one go for parts? Personally, I have found that the greater the capacity of the mag, the price goes up exponentially. A 40 round Pmag is like 35% more than a 30 round Pmag. The 60 round Magpul is around $100 more than the 40 round Pmag. The Beta-C is around double the price of the 60 round Magpul. And the 150 Armatec ($433.67 plus shipping) is one and a half times the Beta-C. The Surefire 100 is hard to find but is cheaper and simpler than the Beta-C. Again, I think that this project is awesome. I certainly would love to buy one, if this becomes available. Please keep up the good work. I am so very envious. Scott Quote HistoryOriginally Posted By canon3825: Originally Posted By Type7SOT: Thanks for your input. I think the main reason people dont buy belt feds is because they are too expensive, not because they are somehow useless in semi auto. Capacity is good, whether in full auto or semi. Look how popular various high cap mags are, whether 40, 60, or 100 rounds. Tons of people buy these mags and run them on semi auto. If a belt fed upper was the same price as a standard upper, I think everyone would have one. Oh, and they are just cool. Respectfully, I disagree, as I don't think that even if the belt fed was the same price, a belt fed is significantly heavier. Transitioning from target to target is slower. Running and gunning with a six or seven pound gun with a 30 round mag is easier and simpler than with a the same lower with a seven and a half pound upper plus the seven pounds of the 200 belt. Certainly a beltfed is very cool. As an owner of the Valkyrie Armaments beltfed system and a DIAS, I think a beltfed has far greater volume of fire than mags. But beyond the cost, a beltfed is just slower and heavier than a carbine with mags. Beyond that, a beltfed is a lot more money to buy. That is just the way it is. Lots more moving specialty parts to break or wear. There is also getting replacement parts. I love my Valkyrie system. The feed mech goes in the modified magwell of the AR lower. So as long as the AR upper is modified for the Valkyrie system, it can be used. I have a standard heavy barreled carbine upper, a MGI (Hydra) upper with three fluted heavy barrels using modified short stroke piston piston kits for heavier rates of fire, and a water cooled 20" heavy fluted barrel DI upper that has had 500 rounds through it with one pull. https://youtu.be/RFcxuOzsoXA?si=5ltNFpu6627CYbVo This video is my wife doing 500 rounds. I am the A gunner. But Valkyrie Armaments is no longer in business. Since I only have one feed mech, where would one go for parts? Personally, I have found that the greater the capacity of the mag, the price goes up exponentially. A 40 round Pmag is like 35% more than a 30 round Pmag. The 60 round Magpul is around $100 more than the 40 round Pmag. The Beta-C is around double the price of the 60 round Magpul. And the 150 Armatec ($433.67 plus shipping) is one and a half times the Beta-C. The Surefire 100 is hard to find but is cheaper and simpler than the Beta-C. Again, I think that this project is awesome. I certainly would love to buy one, if this becomes available. Please keep up the good work. I am so very envious. Scott  500 rd Water Cooled Burst |
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Posted: 6/4/2024 3:21:13 PM EST
[#39]
Speaking of off the shelf parts...I sourced a premade picatinny rail that is the exact right length for the top cover.
I have some flexibilty on the height of the rail, because I have a "rail riser" integrated into the top cover. My plan is to make it a nominal difference in height between the top cover rail and quad rail, such as 3/4". This way if I want to use a front iron sight, I can find an off-the-shelf riser which will make the irons line up.  Attached File |
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Posted: 6/4/2024 3:26:42 PM EST
[#40]
How much longer is your upper than a standard lower?
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Posted: 6/4/2024 3:29:40 PM EST
[#41]
Quote HistoryOriginally Posted By backbencher: How much longer is your upper than a standard lower? It will have about 3/4" more travel than an MCR. It's not quite 3/4" longer than a standard AR15, but I'm accounting for the .075" spacer that the MCR requires to keep from damaging your lower. My design will not have this issue. |
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Posted: 6/4/2024 3:37:55 PM EST
[#42]
Quote HistoryOriginally Posted By backbencher: https://www.ar15.com/forums/armory/It-s-2-14-2024-where-s-the-Cryostructure-Shrike-clone-upper-/65-550065/#i6073262 https://www.ar15.com/media/mediaFiles/203509/1000003374_jpg-3179338.JPG They also are using a longer receiver and bolt carrier. I’m on his list for his 308 BF. |
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Posted: 6/4/2024 4:56:23 PM EST
[#43]
I heard about that is there a time line for it, and will it run on an ar15 lower or will it be large frame? If you know?
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Posted: 6/6/2024 9:38:56 AM EST
[Last Edit: VidaEterna]
[#44]
Quote HistoryOriginally Posted By whiteryno: I heard about that is there a time line for it, and will it run on an ar15 lower or will it be large frame? If you know? Don’t know. He mentioned that the 5.56 upper is first and is priority. I would guess much longer as bugs get discovered in this upper, like the Shrike. It would be awesome to see it run like a scalded ape from the GG. 2 to 3 years maybe? That’s just a guess. I wish him success and will buy his 308 upper once it comes out. I’m on the list… |
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Posted: 6/6/2024 6:05:19 PM EST
[#45]
Big update for today, files for the (stripped) upper receiver have been sent to the machine shop. It took me awhile because I had to provide both a 3D model and engineering drawing. Hopefully in a few weeks I'll be holding an aluminum receiver in my hands.
Now my goals are to finish the rest of the engineering drawings, send them off for machining, and start sourcing a heat treater/finisher. This is happening. |
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Posted: 6/6/2024 9:02:02 PM EST
[#46]
Thus far, this project seems to be moving quickly and smoothly.
Good job. |
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Posted: 6/6/2024 9:07:38 PM EST
[#47]
Quote HistoryOriginally Posted By aod886: Thus far, this project seems to be moving quickly and smoothly. Good job. Thanks! I have 4 kids so its not easy, but I'm commiting 12 hours a week to this project. |
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Posted: 6/8/2024 11:37:48 AM EST
[Last Edit: Type7SOT]
[#48]
I got the rail modeled, and made provisions to attach it to the top cover:
 Attached FileEDIT: I should add that the top cover rail is exactly 3/4 higher than standard, so a 3/4" riser can be used to install a front sight on the handguard. |
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Posted: 6/8/2024 1:26:57 PM EST
[#49]
Quote HistoryOriginally Posted By Type7SOT: I got the rail modeled, and made provisions to attach it to the top cover: https://www.ar15.com/media/mediaFiles/490765/With_Rail_jpg-3235757.JPG Very nice |
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Posted: 6/8/2024 10:55:32 PM EST
[#50]
Quote HistoryOriginally Posted By Type7SOT: I got the rail modeled, and made provisions to attach it to the top cover: https://www.ar15.com/media/mediaFiles/490765/With_Rail_jpg-3235757.JPG EDIT: I should add that the top cover rail is exactly 3/4 higher than standard, so a 3/4" riser can be used to install a front sight on the handguard. Just a suggestion, but it might be worth looking into a way to prevent the top cover from slamming shut using a method similar to the M249. I suppose it could be done through a simple detent that adds a bit of friction to the hinge when opened fully. |
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