AR Sponsor
Joined:
Mar 2025
Posts:
1
EE: 0% (0)
UT, USA
Posted: 3/25/2025 8:27:35 PM EDT
|
Hey everyone. I'm new to this site but not new to guns, somewhat new to shooting suppressed. Sorry if this has been asked before, but I can't seem to find anything on my specific problem. I have a BCM recce 9, 300 blackout. I want to shoot subs suppressed. I've got a CGS Hyperion. I had a Maxim Defense CQB GEN 7 brace with a H1 buffer but I kept having this problem where the bolt would get stuck forward. I'd have to pry it back. I'd load one round at a time since it wouldn't cycle. I don't know if i was short stroking, I'm not sure I understand the concept. I've since switched to a milspec buffer tube and spring and a H3, but haven't shot yet. Am I on the right track? I keep seeing mixed messages, lighter buffer weight, heavier buffer weight.... Any suggestions, advice, or help would be appreciated. |
| Usually a heavier buffer like an h2 is what you need. What ammo are you using? Have you cleaned the chamber good? Adjustable gas block? Lots of factors can play in. |
"Some people have issues. Sounds like he signed up for an entire subscription." ~Brohawk
Proud member of Team Ranstad.
Arfcom St Jude Mafia 3 years
Arfcom callsign: trenchfoot
Proud member of Team Ranstad.
Arfcom St Jude Mafia 3 years
Arfcom callsign: trenchfoot
|
For subs you should be using a standard carbine buffer and spring in my experience Read that Attached File I have the BCM factory 9” upper and it runs how they say it should on their page. |
Joined:
Mar 2025
Posts:
2
EE: 0% (0)
UT, USA
Joined:
Mar 2025
Posts:
3
EE: 0% (0)
UT, USA
| Oh wow. Ok. That's very helpful. Thank you. I've looked on BCM's website but didn't find anything like this. I was using an H. Is there that much of a difference between the two? I mean, I know carbine is what, 3oz. And H is 3.7oz. But I didn't think it would completely cause failure to cycle like it did. Is there anything else that could explain the cycling issues besides buffer? And other than spring or bcg weights. |
|
Subs are magazine picky. I believe it’s worth it to buy mags designed for the 300. I like Lancer clear but haven’t heard anything bad about magpuls new clear either. There is a rib between the stack in the mag that keeps everyone in line. I’m no expert, learned by here, trail and error. 190 Subs will not feed in a 556 pmag. |
-$T has changed the zeitgeist!
- In an age where definitions are used as weapons, there can be no laws.
-History will remember Snark as the language of ignorance.
- In an age where definitions are used as weapons, there can be no laws.
-History will remember Snark as the language of ignorance.
Joined:
Mar 2025
Posts:
4
EE: 0% (0)
UT, USA
|
Originally Posted By Muricha: Subs are magazine picky. I believe it’s worth it to buy mags designed for the 300. I like Lancer clear but haven’t heard anything bad about magpuls new clear either. There is a rib between the stack in the mag that keeps everyone in line. I’m no expert, learned by here, trail and error. 190 Subs will not feed in a 556 pmag. I was thinking it could be the magazine. But I was sure it couldn't possibly be that giving me such a problem. I'm using Lancer mags as well. They are 300 blackout mags. I was going to switch over to pmag to see if that would correct the issue. |
Joined:
May 2023
Posts:
360
EE: 0% (0)
WI, USA
|
When you say the "bolt gets stuck forward", can you describe that in more detail? On the way forward? Also, does it feed and work with supersonic rounds? Pictures are always helpful -- if the problem continues and more help is needed, perhaps share some to help us see. Subs with 300 BLK can be tricky because 5.56 magazines and M4 feed ramps aren't really designed for a fat, long .30 cal projectile, especially the flatter nosed ones. As others have said, Lancers are usually a good bet for subs. Lancer is better than older style PMAGS for 300 subs, in my experience. When you try using the mag, is it full to capacity? Downloaded by a few? Did you try with just 1 round? 2 rounds? Failure in all scenarios? I personally polish all my feed ramps for .300 blk barrels, and round any sharp edges and corners on fed ramps that the fat noses of subs can catch on. I also usually polish the bolt face so that the base of any case sliding up it can't catch on anything. Both are to help feeding. I'm not claiming BCM's parts need that, as I've never used a BCM bolt or .300 BLK barrel. But, reduced friction in those areas can change a feeding issue into a non-issue. Polishing those parts simulates a lot of the "breaking in" that would happen over a couple thousand rounds of shooting, but without wearing the rest of the system in any way. (ARs tend to run smoother after a break in period.) When you fire a single round with no mag, does it eject? |
Joined:
Mar 2025
Posts:
5
EE: 0% (0)
UT, USA
|
Originally Posted By PreacherOfGadget: When you say the "bolt gets stuck forward", can you describe that in more detail? On the way forward? Also, does it feed and work with supersonic rounds? Pictures are always helpful -- if the problem continues and more help is needed, perhaps share some to help us see. Subs with 300 BLK can be tricky because 5.56 magazines and M4 feed ramps aren't really designed for a fat, long .30 cal projectile, especially the flatter nosed ones. As others have said, Lancers are usually a good bet for subs. Lancer is better than older style PMAGS for 300 subs, in my experience. When you try using the mag, is it full to capacity? Downloaded by a few? Did you try with just 1 round? 2 rounds? Failure in all scenarios? I personally polish all my feed ramps for .300 blk barrels, and round any sharp edges and corners on fed ramps that the fat noses of subs can catch on. I also usually polish the bolt face so that the base of any case sliding up it can't catch on anything. Both are to help feeding. I'm not claiming BCM's parts need that, as I've never used a BCM bolt or .300 BLK barrel. But, reduced friction in those areas can change a feeding issue into a non-issue. Polishing those parts simulates a lot of the "breaking in" that would happen over a couple thousand rounds of shooting, but without wearing the rest of the system in any way. (ARs tend to run smoother after a break in period.) When you fire a single round with no mag, does it eject? So I'd fire a round and the bolt would stay forward. But like jammed. I couldn't pull it back with the charging handle. I had to pry it back with a knife and release the casing. I had about 20 rounds in the magazine. So not a full 30. |
Joined:
Mar 2025
Posts:
6
EE: 0% (0)
UT, USA
I'm using the JP Enterprises Silent Capture Spring for the LAW folder in mine. Works great suppressed with subs. I will way it gets dirty quick and can result in brass struck in the chamber after hundreds of rounds. I had to do my first mortaring of an AR a few weeks back to get a round cleared. 
|
Colorado - Stay and fight!
|
Originally Posted By ScoutH57: The 190 Hornady Sub Xs are wierd in my experience too. Quite picky. I’d try another load too I've not had any issues with the Hornady 190gr Sub-x bullets. Everything I've shot was hand loaded and I'm using 300 blackout magpul magazines. Hundreds of rounds so far. |
Colorado - Stay and fight!
|
Originally Posted By DMart81: So I'd fire a round and the bolt would stay forward. But like jammed. I couldn't pull it back with the charging handle. I had to pry it back with a knife and release the casing. I had about 20 rounds in the magazine. So not a full 30. Check to make sure the gas block hasn't come loose and moved forward on the barrel. Is this the first time shooting it, or did it work normally before? Does it lock closed now all the time, regardless of ammo or if suppressed or not? |
Joined:
Mar 2025
Posts:
7
EE: 0% (0)
UT, USA
|
Originally Posted By D_Man: Check to make sure the gas block hasn't come loose and moved forward on the barrel. Is this the first time shooting it, or did it work normally before? Does it lock closed now all the time, regardless of ammo or if suppressed or not? Originally Posted By D_Man: Originally Posted By DMart81: So I'd fire a round and the bolt would stay forward. But like jammed. I couldn't pull it back with the charging handle. I had to pry it back with a knife and release the casing. I had about 20 rounds in the magazine. So not a full 30. Check to make sure the gas block hasn't come loose and moved forward on the barrel. Is this the first time shooting it, or did it work normally before? Does it lock closed now all the time, regardless of ammo or if suppressed or not? I've shot it before. I've had this gun for about 3 years or so. I don't remember what I shot first, but it wasn't subs with a suppressor. Those are recent. It cycled fine without subs and not suppressed. |
AR Sponsor