User Panel
User Panel
User Panel
|
Posted: 8/18/2019 6:58:17 PM EDT
[#1]
Quote HistoryQuoted:
...My goal is to setup a lower that I can SBR and then have 3 uppers in 9mm, 5.56 (shooting suppressed a bit of the time) and 300 BLK (suppressed shooting subs mostly) that will be a "matched set". Any input or thoughts on how a single lower setup will work across the 3 calibers? I expect it won't be perfect for all calibers but I'm hoping for something that works well in all configurations... .22LR 9mm (CMMG Guard) 5.56 5.45 7.62x39 Swapping the buffer and spring I also run: 9mm (Olympic Arms) .40 S&W .45 ACP .308 Win I could also run a bunch more calibers with or without swapping buffer/spring, including .300 BLK, but don't care to get into those calibers. So, is it doable? Absolutely yes. |
|
|
|
Posted: 8/19/2019 4:23:08 PM EDT
[#2]
so if i bought the integrated ejector model endo mag can i mod it to run with the guard?
also, i read @amphibian's website where he was using a dual ramp barrel extension with the endo mag? this thing is so quiet though with a rifle buffer/tube/evo-9!!! even supers didnt hurt my ears.... |
|
|
|
Posted: 8/19/2019 6:31:41 PM EDT
[#3]
Quote HistoryQuoted:
so if i bought the integrated ejector model endo mag can i mod it to run with the guard? |
|
|
|
Posted: 8/20/2019 3:20:28 PM EDT
[#4]
oh thanks.... this forum happens so fast. wish we could get a "per page" cliff notes system so htat folks wouldnt have to keep asking same info...
|
|
|
|
Posted: 8/20/2019 4:03:08 PM EDT
[#5]
Quote HistoryQuoted:
oh thanks.... this forum happens so fast. wish we could get a "per page" cliff notes system so htat folks wouldnt have to keep asking same info... I have an index of my CMMG Guard topics here: http://c3junkie.com/?page_id=956 I update it whenever I come across new data that I think will help everyone. |
|
|
|
Posted: 8/24/2019 12:03:14 AM EDT
[#6]
@CMMGinc, I really want to get one of your 9mm RDB barrel and bolt kits. I would like your 5" option (99D17C3) but I can't seem to find them in stock anywhere. Do you know when your dealers and distributors will starting seeing them back in stock?
|
|
|
|
Posted: 8/24/2019 6:29:47 PM EDT
[#7]
Quote HistoryQuoted:
Hmmm...do you or anyone else know if the HK416 ejector spring will fit in a standard AR bolt? Or is it too fat? Pretty cool that it is braided wire and I would think it would definitely last longer if it fits...but wow...$30 for a spring! Titanium ejector was discussed here: https://www.ar15.com/forums/armory/Full-Auto-CMMG-Guard-Tuning/23-494385/&page=3 I don't know if anyone tried it though. Quote HistoryQuoted:
Quoted:
Y'all should try some HK416 ejector springs. The HK folks assure me they have teutonic space magic, and I have heard claims of great endurance from knowledgeable folk. Perhaps a titanium ejector would reduce mass, also. Just a thought. Would be easy to make Titanium ejector was discussed here: https://www.ar15.com/forums/armory/Full-Auto-CMMG-Guard-Tuning/23-494385/&page=3 I don't know if anyone tried it though. 
If anyone wants to read my latest testing updates w/ the HK spring, you can read it here: http://c3junkie.com/?page_id=954#8-24-19_update |
|
|
|
Posted: 8/26/2019 5:19:26 PM EDT
[#8]
Quote HistoryQuoted:
I broke down and bought a 416 spring and figured this out myself. http://c3junkie.com/wp-content/uploads/2019/08/HK416-EjectorSpring1.png http://c3junkie.com/wp-content/uploads/2019/08/comparison2.jpg If anyone wants to read my latest testing updates w/ the HK spring, you can read it here: http://c3junkie.com/?page_id=954#8-24-19_update |
|
|
|
Posted: 8/28/2019 2:28:00 PM EDT
[#9]
I've been thinking of some ideas to try to extend the ejector spring life. I was thinking about having an ejector made like the DPMS GII ejector seen below. You can see in my pictures how the springs get deformed and almost look like they are binding.
BTW, I've been emailing CMMG support and also pointed them to this thread, my website, this idea and that several people are having ejector failures around the 1k mark. 
I was thinking it would be a pain to make an ejector like this and that this would be a failure point being that the 556 ejector is smaller than .308 as well. Talking to a few guys over email, I had the idea to use a nail as an insert to the spring. One of the guys got these nails from Home Depot. These are stainless steel and seem pretty tough. So my next attempt will be like pictured below. I had to sand down a little right after the tip as nails are kinda deformed there. After that it slides right into the spring nicely. #18 is supposed to be 1.207mm. A 1.25mm drill bit fits nicely inside the ejector spring so this is about perfect. The head of the nail was a little big but no big deal to stick it in a drill and sand down so it moves nicely into the ejector hole now. I need to measure the length, I may not have to even cut the nail or I could even cut the nail and put another on the other side. This should work out better than a custom longer ejector with a spring insert since it can't snap off. 
Seeing it is going to take at least 1K rounds to see if it lasts the same or longer, I figured I'd share with anyone else for a larger test base since this is so easy to do. |
|
|
|
Posted: 8/30/2019 6:57:40 AM EDT
[#10]
Quote HistorySo I received a couple replacement ejector springs from CMMG yesterday and they appear to be the same as the previous ones.
I don't see a bluish/purple tint but my old eyes aren't as sharp as they used to be so maybe I just can't tell. 
|
|
|
|
Posted: 8/30/2019 9:19:15 AM EDT
[#11]
Quote HistoryQuoted:
@CMMGinc, I really want to get one of your 9mm RDB barrel and bolt kits. I would like your 5" option (99D17C3) but I can't seem to find them in stock anywhere. Do you know when your dealers and distributors will starting seeing them back in stock? |
|
|
|
Posted: 8/31/2019 7:12:04 PM EDT
[#12]
@amphibian
Report #2: "New" ejector spring (purple tint) Last time I reported, I had shot about 200 rounds of my FMJ reloads (4.5gr Titegroup behind 115gr FMJ) without issues. Today I had a local Zombie match. I shot approximately 220 rounds of the same ammo, unsuppressed, with the same H buffer and Tubb's flatwire .300 BLK lightweight buffer spring. At around the 20 to 25 round mark of today's match (second stage), I had a failure to eject fully, which caused a stove pipe; carbine hard locked, had to lock bolt to rear and strip 9ARC mag out. So adding the previous round count on this new ejector spring, I now have 1 failure to eject at approx. 220 round mark. The rest of the match went on without any issues. To summarize, this ejector spring has a total of 420 rounds through it with one failure to eject at around the 220 round mark. For comparison, my Oly Arms 9mm upper on the same lower has 3k of the same batch of reloads through it with 0 issues. I thought maybe not to make any conclusions since it was just one failure in 420 rounds. But I went home after the match, and this is what the ejector spring looks like. Left is the ejector spring in question compared to on the right the second spring CMMG sent me (unused). It has started to show the same signs of a bend. It has also permanently compressed to a shorter length. Originally this spring was .909" in length, now it sits at .845". So, to give CMMG the benefit of the doubt, I am going to switch to the backup unused ejector spring, and swap out to a regular carbine buffer spring and carbine buffer, and start counting again. That way I am using exactly what CMMG recommends so there are no excuses. If these issues still persist, I will be contacting them again. Maybe we can put some pressure on them to solve these ejector spring issues. 
|
|
|
|
Posted: 9/1/2019 9:18:03 AM EDT
[#13]
Quote HistoryQuoted:
@amphibian Report #2: "New" ejector spring (purple tint) Last time I reported, I had shot about 200 rounds of my FMJ reloads (4.5gr Titegroup behind 115gr FMJ) without issues. Today I had a local Zombie match. I shot approximately 220 rounds of the same ammo, unsuppressed, with the same H buffer and Tubb's flatwire .300 BLK lightweight buffer spring. At around the 20 to 25 round mark of today's match (second stage), I had a failure to eject fully, which caused a stove pipe; carbine hard locked, had to lock bolt to rear and strip 9ARC mag out. So adding the previous round count on this new ejector spring, I now have 1 failure to eject at approx. 220 round mark. The rest of the match went on without any issues. To summarize, this ejector spring has a total of 420 rounds through it with one failure to eject at around the 220 round mark. For comparison, my Oly Arms 9mm upper on the same lower has 3k of the same batch of reloads through it with 0 issues. I thought maybe not to make any conclusions since it was just one failure in 420 rounds. But I went home after the match, and this is what the ejector spring looks like. Left is the ejector spring in question compared to on the right the second spring CMMG sent me (unused). It has started to show the same signs of a bend. It has also permanently compressed to a shorter length. Originally this spring was .909" in length, now it sits at .845". So, to give CMMG the benefit of the doubt, I am going to switch to the backup unused ejector spring, and swap out to a regular carbine buffer spring and carbine buffer, and start counting again. That way I am using exactly what CMMG recommends so there are no excuses. If these issues still persist, I will be contacting them again. Maybe we can put some pressure on them to solve these ejector spring issues. https://i.imgur.com/MtIIlXv.jpg https://i.imgur.com/27ZHWKh.jpg Yesterday's update: http://c3junkie.com/?page_id=954#8-31-19_update I ran 461 rounds of .40SW through my 40SW bolt with a new CMMG ejector spring. Zero FTE's in .40SW. After 401 rounds of 40SW I tried running it in 9mm and it was extremely unreliable getting a lot of FTE's when I tried this brand new I got about 400 rounds of 9mm suppressed full auto working great w/ the 40SW before but I think I didn't run as much .40SW before switching to 9mm the first time. If you look at my site, I'm trying to use a nail to help prevent the spring from binding/deforming. Below is what it looks like new:  
I need to shoot mine some more but not seeing any real improvement using the nail as a guide right now. It may last the same. I need to get to about 900 rounds to know based on my testing the last time. Really looking forward to your results going to the CMMG recommended buffer/spring setup. |
|
|
|
Posted: 9/1/2019 1:23:04 PM EDT
[#14]
Quote HistoryQuoted:
I've been updating my site w/ my latest ejector spring testing here: http://c3junkie.com/?page_id=954 Yesterday's update: http://c3junkie.com/?page_id=954#8-31-19_update I ran 461 rounds of .40SW through my 40SW bolt with a new CMMG ejector spring. Zero FTE's in .40SW. After 401 rounds of 40SW I tried running it in 9mm and it was extremely unreliable getting a lot of FTE's when I tried this brand new I got about 400 rounds of 9mm suppressed full auto working great w/ the 40SW before but I think I didn't run as much .40SW before switching to 9mm the first time. If you look at my site, I'm trying to use a nail to help prevent the spring from binding/deforming. Below is what it looks like new: http://c3junkie.com/wp-content/uploads/2019/08/Nail-40SW-NewStrength.jpg http://c3junkie.com/wp-content/uploads/2019/08/461-40SW-strength.jpg http://c3junkie.com/wp-content/uploads/2019/08/461-40SW-length.jpg http://c3junkie.com/wp-content/uploads/2019/08/461-40SW.jpg I need to shoot mine some more but not seeing any real improvement using the nail as a guide right now. It may last the same. I need to get to about 900 rounds to know based on my testing the last time. Really looking forward to your results going to the CMMG recommended buffer/spring setup. I haven't really been looking, but do you know if the spring bend is closer to the ejector, or is it at the bottom? I wonder if putting the nail on the side that bends most will be more efficient, and cutting the nail to where the ejector just goes flush with the face of the bolt to prevent any over travel. I know you had said your cut made the ejector go a little past flush. Not sure if it would matter. |
|
|
|
Posted: 9/1/2019 4:03:48 PM EDT
[#15]
Quote HistoryQuoted:
Yeah, I've been tracking your testing. I haven't really been looking, but do you know if the spring bend is closer to the ejector, or is it at the bottom? I wonder if putting the nail on the side that bends most will be more efficient, and cutting the nail to where the ejector just goes flush with the face of the bolt to prevent any over travel. I know you had said your cut made the ejector go a little past flush. Not sure if it would matter. Yeah, mine goes maybe a millimeter beyond the bolt face. I'll be honest that my patience is growing thin messing with the spring loaded ejector. I really want to know if you still have failures going to their recommended buffer/spring setup so we all know if that has anything to do with it. If you run FTE free for say 2K rounds, then I know I just need to give up and stick with the fixed ejector as I am not willing to run my CMMG RDB with that buffer/spring setup as it is too bouncy and fast for my tastes. |
|
|
|
Posted: 9/3/2019 7:32:10 AM EDT
[#16]
Quote HistoryQuoted:
It seems to be still bend near the ejector side even though it is now supported by the nail. I initially was thinking to put the nail on the other side but after seeing how the DPMS GII ejector has the guide on the back of their ejector, I figured that would be the best place. I've been communicating with a couple other guys trying this. One of them made his nail a bit longer than mine and tried to use a standard 556 ejector spring (brand new Sprinco) and it only made it to about 6 mags of full auto suppressed then started having FTE's. He also said that it would still work in semi but would get FTE's with no more than 2 - 3 rounds cycling. Yeah, mine goes maybe a millimeter beyond the bolt face. I'll be honest that my patience is growing thin messing with the spring loaded ejector. I really want to know if you still have failures going to their recommended buffer/spring setup so we all know if that has anything to do with it. If you run FTE free for say 2K rounds, then I know I just need to give up and stick with the fixed ejector as I am not willing to run my CMMG RDB with that buffer/spring setup as it is too bouncy and fast for my tastes. EDIT: I should also state those are two separate BCGs. So do not add the round count together. |
|
|
|
Posted: 9/3/2019 8:37:24 AM EDT
[#17]
Quote HistoryQuoted:
I'll add in my 2cents since I've only ever run the recomended CMMG buffer setup of carbine buffer and regular buffer spring. On the original 8" setup that had a bad barrel I ran roughly 600 rounds through it with zero ejection issues. On my current 16" setup I have roughly 450 rounds through it with zero issues to eject. All 9mm factory loads. Currently shooting only Fiocchi AP9 115gr factory loads. Thanks! |
|
|
|
Posted: 9/4/2019 12:39:18 PM EDT
[#18]
Anyone heard anything about the 10mm version coming out soon? CMMG is announcing something on the 10th according to their website (which would be perfect cuz 10mm lol). But also i think my local dealer might've gotten some Banshees in 10mm a little early at least according to their Instagram story. I suppose we'll find out soon.
|
|
|
|
Posted: 9/4/2019 2:47:20 PM EDT
[#19]
I just saw a 10mm banshee for sale on gun broker the other day.
|
|
|
|
Posted: 9/4/2019 3:25:38 PM EDT
[#20]
Doing a quick Google search, it does seem the 10mm is out there:
https://www.gunsinternational.com/guns-for-sale-online/pistols/cmmg-pistols/cmmg-mk10-banshee-10mm-10a428c-gb-pistol.cfm?gun_id=101287479 https://www.gunbroker.com/Item/830351635 
|
|
|
|
Posted: 9/4/2019 4:27:35 PM EDT
[#21]
Quote HistoryQuoted:
Doing a quick Google search, it does seem the 10mm is out there: https://www.gunsinternational.com/guns-for-sale-online/pistols/cmmg-pistols/cmmg-mk10-banshee-10mm-10a428c-gb-pistol.cfm?gun_id=101287479 https://www.gunbroker.com/Item/830351635 https://p1.gunbroker.com/pics/830351000/830351635/pix884978094.jpg |
|
|
|
Posted: 9/4/2019 4:40:16 PM EDT
[#22]
Quote HistoryQuoted:
Awesome. Can't wait for the barrel and BCG combos to go on sale. Quote HistoryQuoted:
Quoted:
Doing a quick Google search, it does seem the 10mm is out there: https://www.gunsinternational.com/guns-for-sale-online/pistols/cmmg-pistols/cmmg-mk10-banshee-10mm-10a428c-gb-pistol.cfm?gun_id=101287479 https://www.gunbroker.com/Item/830351635 https://p1.gunbroker.com/pics/830351000/830351635/pix884978094.jpg |
|
|
|
Posted: 9/5/2019 7:16:30 AM EDT
[#23]
Quote HistoryQuoted:
Awesome. Can't wait for the barrel and BCG combos to go on sale. |
|
|
|
Posted: 9/5/2019 12:14:47 PM EDT
[#24]
Quote HistoryQuoted: I ordered ~3.5 weeks ago (thought it was in stock @ CMMG) and got an email saying 4-6 weeks. |
|
|
|
Posted: 9/5/2019 8:06:36 PM EDT
[#25]
I have read all 21 pages before asking my build compatibility questions.
My goal is to pair the CMMG RDB BCG and 9mm barrel with QC10’s side charging upper, and QC10’s small frame Glock lower receiver with last round hold open. Thanks to this thread, I understand the LRHO feature may require tweaking. My question is, whether the CMMG RDB BCG is compatible with QC10’s lower? QC10’s website states that it requires “Glock style bolt”. I reached out to both CMMG and QC10 and neither knew if they’re were compatible. Can anyone shed some light on if the CMMG RDB bolt will work with small frame Glock lowers, specifically QC10s? (Link below) https://www.quartercircle10.com/catalog/product/view/id/1583/s/gsf-s-w-pmur-s/category/86/ |
|
|
|
Posted: 9/5/2019 11:31:55 PM EDT
[#26]
Quote HistoryQuoted:
I have read all 21 pages before asking my build compatibility questions. My goal is to pair the CMMG RDB BCG and 9mm barrel with QC10’s side charging upper, and QC10’s small frame Glock lower receiver with last round hold open. Thanks to this thread, I understand the LRHO feature may require tweaking. My question is, whether the CMMG RDB BCG is compatible with QC10’s lower? QC10’s website states that it requires “Glock style bolt”. I reached out to both CMMG and QC10 and neither knew if they’re were compatible. Can anyone shed some light on if the CMMG RDB bolt will work with small frame Glock lowers, specifically QC10s? (Link below) https://www.quartercircle10.com/catalog/product/view/id/1583/s/gsf-s-w-pmur-s/category/86/ https://www.ar15.com/forums/ar-15/CMMG-RDB-System-on-DDLES-Glock-Lower-With-NFA-LRBHO-Upper/15-742058/ Not exactly the same as your setup, but it might give you some ideas on how to make yours work. From what I've read, the QC10 lower is a copy of the order DDLES design. The biggest difference I found was that the CMMG system is designed to work with a mag that sits a little lower in the lower and with a slightly different mag. Basically, I had to limit how high the mag sits in the lower so it wouldn't hit the BCG. Plus I had to machine some room in the upper so the bolt cam could rotate and lock. Someone else on the forum said the CMMG parts were pretty much plug and play with their QC10 lower but I'm not sure which upper they had, so you might get lucky. Hope this helps, Pete |
|
|
|
Posted: 9/6/2019 7:36:55 AM EDT
[#27]
Hellbox,
Yes it will work. I have a large frame QC10 lower I built up with 45acp CMMG RDB barrel/BCG combo. That being said you will need to remove the fixed ejector. There is a screw that holds the ejector into the lower that you will need to remove to pull the ejector out. Mine was very tight to remove. I held the lower inverted in a vise gripping the ejector then gentle rocked and tapped the lower upwards and the ejector popped right out. Now once the ejector is out replace the screw. I believe it holds the little piece of metal that acts as a magazine overinsertion stop in place. Look close it is the little metal dingus that lies beneath the LRBHO arm. BTW the LRBHO works perfect in my set up. There is guidance on QC10’s website I believe if your lower and upper fit does not allow the LRBHO feature to work. Cliff note is snip a coil or two off the spring that functions the “ping-pong” bolt hold open/release lever. This allows for less force of the magazine spring to lift the bolt stop into the path of the BCG and ensure the bolt gets locked back when the magazine is empty. Reliable LRBHO is why I bought the QC10 lower. I would like to try CMMG’s lower as they have a very efficient design of their LRBHO linkage. Now the QC10 side charging upper is another story. I bought one of those and it lacks the cutout for the bolt cam pin. It was designed for a blowback action that does not have a bolt cam pin. Try a Gibbz side charging upper designed for a normal AR15. Even if you buy one of the Gibbz uppers you will need to trim the length of the “gas key” of your CMMG RDB bolt carrier. Amphibian linked a thread with a pic. I emailed Gibbz and they confirmed. You will also need to use their proprietary bolt cam pin that comes with their upper. Side Note: “If anyone is modifying PSA dedicated Glock lowers to accept either LRBHO linkage please drop me a line!” Good luck with your build. I really enjoy my QC10/ CMMG RDB setup. |
|
|
|
Posted: 9/6/2019 11:05:02 AM EDT
[#28]
I greatly appreciate all the helpful responses.
Do you think if I switched to the Gibbz G9/G4 upper paired with CMMG’s MkGs lower I’d have fewer modifications and still retain LRBHO? Perhaps more important, is there any way to make the CMMG RDB BCG work in a left side ejection upper? |
|
|
|
Posted: 9/6/2019 4:44:02 PM EDT
[#29]
Quote HistoryQuoted:
I greatly appreciate all the helpful responses. Do you think if I switched to the Gibbz G9/G4 upper paired with CMMG's MkGs lower I'd have fewer modifications and still retain LRBHO? Quote HistoryQuoted:
I greatly appreciate all the helpful responses. Do you think if I switched to the Gibbz G9/G4 upper paired with CMMG's MkGs lower I'd have fewer modifications and still retain LRBHO? Perhaps more important, is there any way to make the CMMG RDB BCG work in a left side ejection upper? |
|
|
|
Posted: 9/10/2019 6:41:45 AM EDT
[#30]
Well if you all hadn't already figured it out. CMMG made it official at midnight. 10mm versions now available.
|
|
|
|
Posted: 9/10/2019 11:38:38 AM EDT
[#31]
Haven't received a tracking number yet, but CMMG marked my order from 8/6 as complete on 9/9 to give y'all an idea on lead times for the 5in kit.
|
|
|
|
Posted: 9/10/2019 12:57:03 PM EDT
[#32]
Quote HistoryQuoted: Well that is bullshit. I ordered one yesterday from them only because I thought it was in stock. I would have rather waited a few weeks and then got them from a distributor for less money if I had known that... |
|
|
|
Posted: 9/10/2019 4:03:06 PM EDT
[#33]
Quote HistoryQuoted:
Well if you all hadn't already figured it out. CMMG made it official at midnight. 10mm versions now available. |
|
|
|
Posted: 9/16/2019 7:31:47 PM EDT
[#34]
I've found the ejector springs that come from CMMG to be completely unacceptable. The company I work for does some builds with these kits, and in all of those the ejector spring has been replaced with a Springco Enhanced Ejector Spring.
Here's a picture of one that has over 1000 rounds through it. Mostly in full auto, this one. It has compressed a bit, but it is still working. I pulled it out just to see if it was getting crunched in there or anything. This one is still working fine, no issues with ejection. 
|
|
|
|
Posted: 9/16/2019 8:33:45 PM EDT
[#35]
Quote HistoryQuoted:
I've found the ejector springs that come from CMMG to be completely unacceptable. The company I work for does some builds with these kits, and in all of those the ejector spring has been replaced with a Springco Enhanced Ejector Spring. Here's a picture of one that has over 1000 rounds through it. Mostly in full auto, this one. It has compressed a bit, but it is still working. I pulled it out just to see if it was getting crunched in there or anything. This one is still working fine, no issues with ejection. https://i.imgur.com/1FihLP1.png All my testing is in full auto also. The CMMG ejector spring is shorter than a standard 556 spring but gauge of wire is thicker and it is stiffer. Yes, it will get deformed and fail at around 1k rounds in my experience. I've also tested several different 5.56 ejector springs including the Sprinco and they all die in less than 1K rounds in my experience. Yes other 556 springs are longer but they are not as strong and don't last as long. As I've stated several times, I really like the CMMG RDB but the ejector spring is the Achilles heal of the system. My fixed ejector CMMG RDB configuration has been flawless but requires proprietary parts and modifications. My full auto CMMG testing: http://c3junkie.com/?page_id=538 |
|
|
|
Posted: 9/20/2019 2:25:50 PM EDT
[#36]
ive bolted a cheesy wood mag block to an 80% lower to run my cz75 mags...
i had bought the wrong endo mags... if anyone wants to switch blowback for cmmg endomags lemme know |
|
|
|
Posted: 9/22/2019 8:22:03 PM EDT
[#37]
Went to a Steel Challenge match earlier today and took the 16" CMMG 9mm RDB to shoot. Placed 7th overall out of 44. Also placed 2nd out of 6 in PCCO division. 1st was one of the top shooters in the nation and this was only my second time ever shooting Steel Challenge.
Ran probably 150ish rounds more through the rifle today. For a total of around 600 rounds. I cleaned it at 150 rounds and haven't cleaned it since. In the last 300 rounds I've had 3 light primer strikes. Could be hard primers, all the same ammo, or just time for a cleaning. As the lower I'm using has a Geissele trigger and has never had an issue with light strikes in the thousands of rounds I've put though it with other uppers. I'm gonna clean it tomorrow and we'll see if there is anything visually wrong. Still no ejection issue to hint at. The ROs were even commenting on how hard it was ejecting as it was coming out and hitting them. |
|
|
|
Posted: 9/22/2019 9:17:56 PM EDT
[#38]
Quote HistoryQuoted:
Went to a Steel Challenge match earlier today and took the 16" CMMG 9mm RDB to shoot. Placed 7th overall out of 44. Also placed 2nd out of 6 in PCCO division. 1st was one of the top shooters in the nation and this was only my second time ever shooting Steel Challenge. Ran probably 150ish rounds more through the rifle today. For a total of around 600 rounds. I cleaned it at 150 rounds and haven't cleaned it since. In the last 300 rounds I've had 3 light primer strikes. Could be hard primers, all the same ammo, or just time for a cleaning. As the lower I'm using has a Geissele trigger and has never had an issue with light strikes in the thousands of rounds I've put though it with other uppers. I'm gonna clean it tomorrow and we'll see if there is anything visually wrong. Still no ejection issue to hint at. The ROs were even commenting on how hard it was ejecting as it was coming out and hitting them. |
|
|
|
Posted: 9/22/2019 9:47:59 PM EDT
[#39]
Quote HistoryQuoted:
What do you think your total round count is with that bolt? Get to a thousand yet? I don't think I've ever encountered any light hits myself. Using Geissele SSF. |
|
|
|
Posted: 9/23/2019 12:28:27 AM EDT
[#40]
Quote HistoryQuoted: Total with this bolt is 600. As I got a new bolt with the new barrel. I'm leaning towards the light strikes being primer related but not 100% sure. Will know a little more tomorrow. I have a Geissele SSA trigger on my Colt 901 SBR lower that I use for everything, including the CMMG RDB upper. I probably have about 1300 rounds total through this RDB upper, not a single light primer strike. I've shot Winchester White Box 115gr, Winchester USA Forged 115gr, Federal Aluminum 115gr, and several of my own loads with Remington primers. Just some data in case you need it. |
|
|
|
Posted: 9/23/2019 4:17:04 PM EDT
[#41]
Had my first failures to eject the other day with my 16" RDB 9mm setup. Only had around 600rds on it. Disappointing the ejector spring is the weak link as it's not exactly an easy swap at the range barring having a complete spare bolt assy. When i swapped mine out for a new one, the old spring looked like a lot of the ones in this thread that were short and bent out of shape. Just another data point for those interested.
|
|
|
|
Posted: 9/23/2019 6:04:35 PM EDT
[#42]
So I’m not exactly sure what my problem is.
I think I’m having failures to extract, the empty case is pulling slightly out of the chamber, and the next round is getting pushed up into the stuck empty case. Would this be failure to extract or eject? No stovepiping though. FA with Guard endo mags. My guard extractor spring is 1/8” shorter than a 556 extractor spring. |
|
|
|
Posted: 9/23/2019 7:50:50 PM EDT
[#43]
Its probably a failure to eject issue as has been mentioned here on this thread by others. Contact CMMG for a free replacement ejector spring. I had to do the same. If we all get on their ass about this issue, maybe they'll find a permanent solution to this.
I noticed some 10mm reviews had no issues ejecting and they got past the 1k round marks. Hopefully they can extent that ejector spring reliability to the 9mm, and get much much farther than 1k rounds. |
|
|
|
Posted: 9/23/2019 7:59:33 PM EDT
[#44]
^yea I went back to page 10 where amphibian first mentioned the ejector spring issue.
It just seems like mine is more of an extraction issue. But I’m not certain and you may be right. Either way I’ll contact cmmg. As far as the extractor spring; anyone else pull theirs and notice a difference compared to a 556 extractor spring? |
|
|
|
Posted: 9/23/2019 9:05:10 PM EDT
[#45]
Quote HistoryQuoted:
^yea I went back to page 10 where amphibian first mentioned the ejector spring issue. It just seems like mine is more of an extraction issue. But I'm not certain and you may be right. Either way I'll contact cmmg. As far as the extractor spring; anyone else pull theirs and notice a difference compared to a 556 extractor spring? If you look at my site and read my full auto testing here: http://c3junkie.com/?page_id=538 I posted this at the botttom, "At this time, I am still very happy with my fixed ejector setup. For some reason, my bolt spring is almost dead and barely pushes the bolt out of the carrier and the extractor spring is about dead also with very little tension.but it still runs 100% so I'm going to keep running it till it stops working." I can literally shake the bolt and watch the extractor flop around and that setup with my fixed ejector is 100%. I also posted that I tested firing the Guard with NO extractor installed and it fires several rounds before jamming. I believe the Guard is like the MP5 in that both guns don't really need an extractor to 'extract'. The extractor does need to be there for the brass to 'pivot' on. |
|
|
|
Posted: 9/27/2019 10:57:56 AM EDT
[#46]
Quote HistoryQuoted: What kind of ammo are you using? I have a Geissele SSA trigger on my Colt 901 SBR lower that I use for everything, including the CMMG RDB upper. I probably have about 1300 rounds total through this RDB upper, not a single light primer strike. I've shot Winchester White Box 115gr, Winchester USA Forged 115gr, Federal Aluminum 115gr, and several of my own loads with Remington primers. Just some data in case you need it. The first 150 rounds through the gun were a mixed bunch of different ammos I was testing accuracy with. None of those had light strikes. Since then it has been a 450 round diet of only Fiocchi 9AP 115grn rounds. 3 of those 450 were light strikes. All during matches. Basically only have had time to shoot matches since initial testing. I cleaned the rifle yesterday and nothing really stood out at me as wrong. The firing pin channel was a little dirtier than I would like to see but it didn't seem to impede the function of the firing pin. The lower was plenty clean. The trigger is a Geissele G2S that has never had a light strike issue with any other upper I have used it with. That lower/trigger combo is probably approaching 5-6000+ rounds on it. I pulled the hammer pin, cleaned it, and lubed it back. We'll see if that changes anything. I still think it's probably ammo related but if I see more light strikes my next test will be a new hammer spring. Still no ejection issues at 600 rounds with the carbine spring and buffer setup. |
|
|
|
Posted: 10/4/2019 1:42:18 AM EDT
[#47]
I have an SBR QC10 small frame Glock lower. I removed the extractor and feed ramp from the lower and am able to put the 9mm banshee upper and lower together. Unfortunately I'm unable seat empty Glock mags on a closed bolt. Is this normal for this upper/lower combo? Am I going to have modify the bolt catch to make the mags seat lower?
|
|
|
|
Posted: 10/4/2019 8:35:09 AM EDT
[#48]
Quote HistoryQuoted:
I have an SBR QC10 small frame Glock lower. I removed the extractor and feed ramp from the lower and am able to put the 9mm banshee upper and lower together. Unfortunately I'm unable seat empty Glock mags on a closed bolt. Is this normal for this upper/lower combo? Am I going to have modify the bolt catch to make the mags seat lower? |
|
|
|
Posted: 10/4/2019 7:12:21 PM EDT
[#49]
Just out of curiosity, has anyone installed the 9mm shell deflector and dust cover on a guard? I've got one of the cmmg ones in my parts bin.
|
|
|
|
Posted: 10/4/2019 9:39:03 PM EDT
[#50]
Quote HistoryQuoted:
Just out of curiosity, has anyone installed the 9mm shell deflector and dust cover on a guard? I've got one of the cmmg ones in my parts bin. |
|
|
Win a FREE Membership!
Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!
You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.
AR15.COM is the world's largest firearm community and is a gathering place for firearm enthusiasts of all types.
From hunters and military members, to competition shooters and general firearm enthusiasts, we welcome anyone who values and respects the way of the firearm.
Subscribe to our monthly Newsletter to receive firearm news, product discounts from your favorite Industry Partners, and more.
Copyright © 1996-2024 AR15.COM LLC. All Rights Reserved.
Any use of this content without express written consent is prohibited.
AR15.Com reserves the right to overwrite or replace any affiliate, commercial, or monetizable links, posted by users, with our own.
