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[ARCHIVED THREAD] - Thoughts on the CMMG Guard? (Page 16 of 25)
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Quoted: Same here which is why I'm looking to give the Endomag a try. I guess I could remove the LRBHO altogether on the QC10 lower but I'd really like to have the feature. |
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Quoted:
To use the Guard with the DDLES / Q10 lower, I have to remove the ejector? Is that correct? AND I can use my high dollar trigger! |
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Quoted:
If you followed the Endomag thread you may have read that the bolt hold open tab at the back of the follower can stick up too much and hold the bolt open with one round left in the mag. It may need a bit of shaving down. For me, the endo mag is working. I just have this Glock lower and it’s SBR, so I’m married to it. |
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Quoted: We are specifically talking about a Glock pattern lower, not the endo mag. For me, the endo mag is working. I just have this Glock lower and it’s SBR, so I’m married to it. Quoted: We are specifically talking about a Glock pattern lower, not the endo mag. For me, the endo mag is working. I just have this Glock lower and it’s SBR, so I’m married to it. Quoted:
Same here which is why I'm looking to give the Endomag a try. |
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Quoted: Tried out my new guard upper on my QC10 Glock lower over the weekend. i did remove the Ejector, but that's all i did. Worked great! LRBHO worked as well. So nice to be able to use standard AR triggers as well. Going to be building a guard pistol upper soon soon as i can find a decent price on the 5" barrel and bolt. |
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Quoted: Awesome. You didn’t find the need to add a spacer of sorts? Just curious. If you were talking about the latter, I'm just using a standard carbine model kynshot hydraulic buffer (compresses to 3.25"). The Guard BCG setup as far as i can tell just uses the same stroke length as a standard 5.56 bcg compared to a straight blowback 9mm bolt. |
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Quoted:
I've been reading to get the Guard 9mm upper to work with Colt patterned lower, quite a few modifications need to be made. Mainly to each magazine. Correct me if I am wrong. That's not something I want to do. I made it work with NO mods to the mags....I detailed all this some time ago here: http://c3junkie.com/?page_id=597 The main thing is you mod the catch instead of the magazine so it sits lower....see my link above for the other mods. 
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@amphibian
If the catch is modified, does the magazine wiggle in the mag well? I’m thinking because it’s only captured by half of the catch. Well. I took out the ejector and feed ramp from the DDLES lower and the Glock magazine sits too high. So I’ll have to modify the magazine catch on my Glock lower as well. |
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Quoted:
@amphibian If the catch is modified, does the magazine wiggle in the mag well? I'm thinking because it's only captured by half of the catch. Well. I took out the ejector and feed ramp from the DDLES lower and the Glock magazine sits too high. So I'll have to modify the magazine catch on my Glock lower as well. However, do note that removing material from the top of the mag catch does allow the mag to be pushed up so keep that in mind if you try using your mag as a monopod...which I personally don't do. |
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I just got done with the first test of a new upper I built with the Guard 8" barrel and BCG. I had a few FTF's but I have not determined whether it was an ammo issue or something else. I'd like to eliminate the buffer and/or spring as the culprit, so is there any kind of consensus on the best spring/buffer set up? Less recoil is always better but reliability would be my #1 concern by far. What I have in there now is a standard 5.56 carbine spring and a 3 oz. buffer. |
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Quoted:
I just got done with the first test of a new upper I built with the Guard 8" barrel and BCG. I had a few FTF's but I have not determined whether it was an ammo issue or something else. I'd like to eliminate the buffer and/or spring as the culprit, so is there any kind of consensus on the best spring/buffer set up? Less recoil is always better but reliability would be my #1 concern by far. What I have in there now is a standard 5.56 carbine spring and a 3 oz. buffer. |
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Quoted:
I just got done with the first test of a new upper I built with the Guard 8" barrel and BCG. I had a few FTF's but I have not determined whether it was an ammo issue or something else. I'd like to eliminate the buffer and/or spring as the culprit, so is there any kind of consensus on the best spring/buffer set up? Less recoil is always better but reliability would be my #1 concern by far. What I have in there now is a standard 5.56 carbine spring and a 3 oz. buffer. |
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Quoted:
New build may not be broken in yet. If it is and you still have problems you can spring for the CMMG tuning kit for 20 bucks or try a heavier buffer. Amphibians' posts are full of info and test results. Read back and follow his lead. I did and got great results. I'll look back over the previous posts. I was hoping to keep the lower to where I could literally just swap uppers back and forth between 5.56 and 9 mm but that is probably not realistic and I just need to set it up as a dedicated 9 mm. |
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How many people here that built their own upper with the bolt/barrel combo used uppers with enlarged ejection ports, or widened the ejection port of a regular upper receiver? On the last page, Steamedliver sounded like he was having good luck with a standard upper. I've seen it mentioned that the widened port was needed more for the 45 Guard? Attached File |
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Quoted: Thanks. I hate having to "break in" a gun but it appears I still need to, and 150 rds is probably not enough to do it. I'll look back over the previous posts. I was hoping to keep the lower to where I could literally just swap uppers back and forth between 5.56 and 9 mm but that is probably not realistic and I just need to set it up as a dedicated 9 mm. I settled on the Kynshot 3.25" AR10 hydraulic buffer and a plain round wire carbine spring. I used the 3.25" buffer since my Magpul CTR tube is shorter than the A5 that amphibian settled on. When I get my can for the Banshee this summer I may have to tweak a bit. |
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Quoted: I was hoping to keep the lower to where I could literally just swap uppers back and forth between 5.56 and 9 mm but that is probably not realistic and I just need to set it up as a dedicated 9 mm. |
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Quoted: I do this. I have an Vltor A5 extension with the ARH2 buffer & standard A5 rifle spring. It works with 9mm & 5.55 in semi/full auto (suppressed and unsupressed). It also work in semi with 300BLK (suppressed & unsupressed) but I have yet to try it FA. detail here http://c3junkie.com/?page_id=654 |
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Quoted:
is the Radial Delayed Blowback 9mm a guard or banshee? website is confusing. Banshee is basically anything that is pistol or NFA length regardless of how it works. Guard isn't gone though but if you see in the product name like MkG - the G is Guard which = the radially delayed blowback. See this table for example of the Banshee line...it has a column for 'action design' https://www.cmmginc.com/product-category/banshee/banshee-100-series/ |
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Based on the info in this thread, for my SBR with CMMG Guard 8" upper I plan to order:
PA-10 buffer Tube (substituted for Vltor A5) Kynshot 9mm Buffer model RB5007 Tubbs AR-15 flat wire spring model ARBUF Is this the setup I want? Just making sure before I order; particularly that this is the right model buffer and spring (not AR10 spring). |
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Quoted:
Based on the info in this thread, for my SBR with CMMG Guard 8" upper I plan to order: PA-10 buffer Tube (substituted for Vltor A5) Kynshot 9mm Buffer model RB5007 Tubbs AR-15 flat wire spring model ARBUF Is this the setup I want? Just making sure before I order; particularly that this is the right model buffer and spring (not AR10 spring). That setup works great for all of my 556 uppers except the belt fed. However, I know some people had some issues with this configuration w/ the newer Guard barrels that have the single feed ramp and trying to use Endomags. Using the standard carbine buffer and spring would work but not the above, UNLESS, the extension was contoured like the early Guard barrels which were using standard M4 extensions (dual feed)....which is why I was saying you need to make sure you are 100% with the CMMG recommended config before changing anything. |
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Quoted:
However, I know some people had some issues with this configuration w/ the newer Guard barrels that have the single feed ramp and trying to use Endomags. Using the standard carbine buffer and spring would work but not the above, UNLESS, the extension was contoured like the early Guard barrels which were using standard M4 extensions (dual feed)....which is why I was saying you need to make sure you are 100% with the CMMG recommended config before changing anything. Also, anyone have comparison pics of the new vs old feed ramps on the guard barrels? |
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I have the single ramp. I'm not doubting that some folks had issues using the Kynshot buffer and Endomags with the single ramp version, but I really don't understand why. I would think that if the single ramp is not as good as the double M4 type deal, then that would be its own issue aside from whatever buffer you're using.
Reliability is still #1 of course but it seems like this gun kicks way more than it should. So if the Kynshot buffer is a no-go I may try what Joker23 did and used the SOB buffer instead. He said that the recoil was minimal. At present, with the standard or H2 buffer and spring I would say that recoil is more than a 5.56 AR and about the same as an AK, and that's not what I'm looking for. |
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Quoted:
I have the single ramp. I'm not doubting that some folks had issues using the Kynshot buffer and Endomags with the single ramp version, but I really don't understand why. I would think that if the single ramp is not as good as the double M4 type deal, then that would be its own issue aside from whatever buffer you're using. Reliability is still #1 of course but it seems like this gun kicks way more than it should. So if the Kynshot buffer is a no-go I may try what Joker23 did and used the SOB buffer instead. He said that the recoil was minimal. At present, with the standard or H2 buffer and spring I would say that recoil is more than a 5.56 AR and about the same as an AK, and that's not what I'm looking for. I think one of the Kynshot hydraulic buffers may be your best option. |
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Quoted: I tried the Kynshot AR-15 hydraulic buffer and the recoil was not acceptable. (I didn't try their 9mm hydraulic buffer). The AR-10 buffer with plain carbine spring is VERY soft. After trying a dozen combinations of 3 buffers/springs based on amphibians' testing imo the AR-10 hydraulic buffer/plain round carbine spring combo is the smoothest for my 5" RDB Banshee, especially in full auto. I think one of the Kynshot hydraulic buffers may be your best option. Spring forces documented by the David Tubb Youtube video. A2 (old) 7.6lb closed, 14.5lb open A2 (new) 9.1lb closed, 16.7lb open Tubb Flatwire 10.5lb closed, 16.3lb open Tubb .308 Flatwire 13lb closed, 16.7lb open SpringCo White ? (standard) 8.3lb closed, 16.3lb open SpringCo Red (extra) 10.5lb closed, 18.4lb open SpringCo Orange (increased) 13.9lb closed, 24.8lb open I don't think the 556 hydraulic's do anything unless you have a very overgassed gun. Some data is here: http://c3junkie.com/?page_id=430 556 Kynshot 
308 Kynshot (same length as a 556 Carbine buffer)..I think the same one HDSledge is using...this would be my first choice if not using an A5 length buffer tube. 
9mm Kynshot: 
I believe the two above are actually absorbing some of the initial recoil impulse but I could be totally wrong. All I know is they are the softest shooting for me w/ the spring I'm using (Tubb flat springs). One of these days I may cut a slot in a buffer tube and use a high speed camera to see what is actually happening. |
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Quoted:I think one of the Kynshot hydraulic buffers may be your best option. Will post results as it might be helpful to those doing a similar build. Unfortunately, most of us don't really care about cyclic rate since we're poors and don't have FA. Just trying to get the softest shooting gun possible that still runs as close to 100% as I can get it. |
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Quoted: I think I'm going to try the SOB buffer, flat wire spring, and spacer setup like Joker23 used first. It worked for him and is a lot cheaper. If that doesn't do what I want I'll try the Kynshot. Will post results as it might be helpful to those doing a similar build. Unfortunately, most of us don't really care about cyclic rate since we're poors and don't have FA. Just trying to get the softest shooting gun possible that still runs as close to 100% as I can get it. I had 3 buffers and 3 springs. In one visit to the range I installed spring 1 and tried all 3 buffers with supers then subs, then spring 2, etc., . 18 combinations. Having a few parts combos to try one after another was the key for me. Some of the effects of a change are huge, some small, but all are discernible. It was a real education for me on the platform and how it can be tuned. |
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Quoted: I think I'm going to try the SOB buffer, flat wire spring, and spacer setup like Joker23 used first. It worked for him and is a lot cheaper. If that doesn't do what I want I'll try the Kynshot. Will post results as it might be helpful to those doing a similar build. Unfortunately, most of us don't really care about cyclic rate since we're poors and don't have FA. Just trying to get the softest shooting gun possible that still runs as close to 100% as I can get it. The SOB had about the same cyclic rate as the hydraulic buffer I settled on so it wasnt the cyclic rate that made me prefer the hydraulic over the SOB...it was the softness/smoothness. I do like the like the SOB buffer eventhough I did have one fail on me and posted pics of it somewhere here. Griffin took care of me and sent me a replacement that is clearly a new generation version. |
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Since Amphibian took the time, trouble, effort, and energy to do a lot of testing, I based my decision off of his research. I went with the SOB over the hydraulic purely on price.
I posted my results somewhere else, but I tested 5.56 supersonic, 300 Blackout subsonic and supersonic, suppressed and unsuppressed. After switching from a standard carbine buffer, tube, and spring to an A5 tube, SOB buffer, flatwire spring, and spacer, I did notice a difference in how soft the rifle shot. The one issue I have is that subsonic 300 Blackout without the suppressor will not lock the bolt back on the last round. I decided that I could live with that - I don't normally shoot subs unsuppressed, just did it for testing. When I put my Guard upper together, I had some issues with rounds jamming while feeding, but those issues went away after ~250 rounds. I wasn't aware that there were different feed ramps on the Guard barrels, so I took a look at mine, it looks like the one wide ramp. I think I mentioned it before, but with this being my first 9mm AR, I didn't have anything to compare it to, but it sure feels soft shooting to me. A few times, with the first round from a new mag, I had to check the target to make sure the round fired and I didn't have a 'pop and no kick'. It wasn't every time, so it may have just been the cheap ammo I was using. I have a suppressor in jail right now, so it'll be interesting to see how it shoots suppressed. Of course at the rate things are going now, it'll be Christmas before it's out of jail. |
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Quoted:
Since Amphibian took the time, trouble, effort, and energy to do a lot of testing, I based my decision off of his research. I went with the SOB over the hydraulic purely on price. The one issue I have is that subsonic 300 Blackout without the suppressor will not lock the bolt back on the last round. I have a suppressor in jail right now, so it'll be interesting to see how it shoots suppressed. Of course at the rate things are going now, it'll be Christmas before it's out of jail. Don't have my can yet either. Are the delays at BATF getting worse? Was 7 months for my last stamp. |
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Quoted:
is the Radial Delayed Blowback 9mm a guard or banshee? website is confusing. I think that effectively, the Guard, MkG/MkGs, and Banshee are all the same. |
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Finally got my 8" Guard bolt, barrel, and lower together and tested out yesterday. Ran 100rnds each of Blazer brass 115 and 124gr, 200rnds of my 100gr titegroup cheapo plinking load, and 33rnds of Fed xm9001 HPs I had laying around without a hiccup. Sweet. This was with a regular carbine spring and 3oz carbine buffer. I couldn't give a solid number on the difference between the recoil impulse of my 16" blowback glock mag carbine with a hydraulic buffer and the guard, but it was very noticeable. Dot movement off the target was also markedly decreased. I also have an h and h2 buffer to test next time out. Has anyone noticed the edges of the feed ramp leave some pretty heavy dents and scratches on the brass? |
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Quoted:
Finally got my 8" Guard bolt, barrel, and lower together and tested out yesterday. Ran 100rnds each of Blazer brass 115 and 124gr, 200rnds of my 100gr titegroup cheapo plinking load, and 33rnds of Fed xm9001 HPs I had laying around without a hiccup. Sweet. This was with a regular carbine spring and 3oz carbine buffer. I couldn't give a solid number on the difference between the recoil impulse of my 16" blowback glock mag carbine with a hydraulic buffer and the guard, but it was very noticeable. Dot movement off the target was also markedly decreased. I also have an h and h2 buffer to test next time out. Has anyone noticed the edges of the feed ramp leave some pretty heavy dents and scratches on the brass? 
You can post images using an external picture host, imgur for example. But I've noticed the brass thing. From what i can tell it happens during ejection/extraction as the casing is rubbing on the inner right side of the barrel extension lugs. Seems to be not as bad from live fire, but if you cycle rounds through it'll gouge them pretty convincingly. |
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Put about 200 more rounds through my 9 mm AR with the CMMG 8" Guard barrel and BCG and Endomags. This was with the Griffin SOB buffer, Tubb's flat wire spring, and New Frontier Armory spacer. I used a Spike's 308 buffer tube. Had zero issues and I did a few mag dumps as fast as I could go to try to get it to mess up, but it ran like a champ. I did switch the Endomags over from Gen II to Gen III P-mags. I don't know that, or why, this would make any difference but since the few jams I had previously were when I was using Gen II's, I am sticking with Gen III's at this point. It's hard to tell for sure but I'd say recoil is on par with my MPX. The Kynshot buffer would probably shoot a bit softer but for someone on maybe a bit tighter budget, this setup certainly seems to work. |
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Quoted:
Anyone have any idea if the guard system would work with the matrix arms side charging 9mm upper? |
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Well, you can buy direct from their USA website for $265: https://dpmsystems.us/collections/ar-15
... but the site looks a bit abandoned with a blog post about SHOT 2016 being the most current and the top banner still advertising a 7% Christmas discount... Zahal also has it available for $250 with free shipping: https://zahal.org/product/m16-ar15-adjustable-recoil-reducing-buffer-assembly-by-dpm/ And Optics Planet has it for $235 with free shipping on a short predicted back order: https://www.opticsplanet.com/dpm-recoil-buffer-assembly-for-m-16-ar-15-223-5-56-calibre-rifles.html It honestly looks like a lot of expense and hassle... You could just get the Taccom buffer and use it in an A5 tube for half the cost: https://taccom3g.com/product/taccom-pcc-adjustable-buffer-system/ You would probably have to remove the pinned carrier weight since the buffer is 6.2 ounces. Even the MBX Extreme buffer is half the price of the DPM System: https://mbxextreme.com/index.php?page=PCC_Buffer I've never tried one of these systems but from reading online it seems like a lot of expense for very little gain with these complicated spring systems. |
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Quoted:
I doubt it, most 9mm uppers do not have provisions for a cam pin. The only 9mm upper that does is the gibbz g9, but I'll save you the expense and bs headache (you can take a look at my posts in the last couple pages of the C5 lower thread), from what I can tell the guard needs the longer 5.56 ejection port for reliability. If I limited the carrier travel to within the the 9mm ejection port it would run reliable, but when I did that it recoiled as much as a blowback 9mm so whats the point. |
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Just got back from the range. Used my 3 Endomags with the Guard upper I built.
First 100 rounds were Federal 115gr. 30 through each of the 3 Endomags then the last ten rounds from a mag I grabbed at random. Flawless. I noticed again today that the very first round from the mag feels very soft compared to the rest of the rounds. No idea why. Then I used a box of WWB 115gr that I didn't even know I had. I found it in the bottom of my range bag. I put 30 in one of the Endomags and had 4 or 5 failures to eject and the empty brass got mangled. Put the next 20 in the same mag and had another couple failures to eject. My lower has an A5 receiver extension, Tubbs flatwire spring, and Griffin SOB buffer (and a spacer). At this point I was wishing I had brought a standard carbine spring and/or buffer with me. The last 90 rounds were 115gr Aguila. 30 in each of the 3 Endomags. Flawless. Right now I'm just going to blame the failures on the box of WWB. Everything before and after was perfect. Still may keep a standard carbine spring and buffer in my range bag just in case. ETA - When I say failure to eject, in each instance, the bolt tried to feed a new round, but the empty brass was not thrown clear, preventing the new round from going in all the way and mangling the empty brass in the process. The more I think about it, I'm using a standard upper, not one with a widened port. Only happened with that one box of rounds, though. |
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Quoted:
i have a piston upper assy, think if i opened up bolt for round to sit, and added the angle cuts to the locking lugs it would work as the guard? (I was thinking the same thing when the Guard first came out; wanted to integrate the Guard bolt with a Rock River PDS upper. Only after I bought a Guard did I find out this small yet important detail!) |
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Quoted:
Assuming your piston carrier has the same cam pin path as a standard DI gun, then no. The Guard carrier uses a shorter cam path compared to a DI gun. (I was thinking the same thing when the Guard first came out; wanted to integrate the Guard bolt with a Rock River PDS upper. Only after I bought a Guard did I find out this small yet important detail!) Quoted:
Quoted:
i have a piston upper assy, think if i opened up bolt for round to sit, and added the angle cuts to the locking lugs it would work as the guard? (I was thinking the same thing when the Guard first came out; wanted to integrate the Guard bolt with a Rock River PDS upper. Only after I bought a Guard did I find out this small yet important detail!) as far as opening up the bolt face, if memory serves a bolt for 5.45x39 should work for 9mm. |
[ARCHIVED THREAD] - Thoughts on the CMMG Guard? (Page 16 of 25)
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