Going to build a dedicated suppressed upper.
To not have to deal with two stamps (besides, why shoot unsuppressed?), it’s going to be right at a 12" to 12.5" barrel with a permanently attached reflex style suppressor. The suppressor is going to be a custom build, so no brand available. It’s going to end somewhere close to 17", might go to 18" but hopefully not.
Since it will be permanent, firing without the suppressor is a non-issue. Hopefully, it will run whatever ammo I throw in it, but the real goal is to run with quality ammo.
So, the question is, can a midlength gas system do this reliably, or would it be better served by a carbine gas system?
I know dwell time is short on a midlength like this, but the suppressor will add back pressure. I don’t want a gigantic gas port. There will be a short brake on the muzzle to help direct gas back into the reflex chamber. Either one chamber, or just holes off the bore. Don’t know if the brake will make a big difference, so I mention it.
What say the gurus? I’m barrel shopping. Looking at BCM.
At least 2 M4C members have 11.5 mids coming in shortly for suppressed only builds.
I will start a thread to discuss the build, the issues, and how it all works (or doesn’t). But to be honest, as I wait for the barrel I am beginning to question why I didn’t go with a carbine gassed 11.5, a proven system.
I have been doing a T&E on a Rainier Arms 12.5" Mid length gas system barrel. I have shot it with and without a can (AAC SDN6). So far no issues but I have not shot any crap ammo yet. That is on my list of things to do still.
Iraqgunz, I know they don’t. But, they make a 14.5", and I have a lathe.
I will be building the suppressor as well.
Not concerned with whether I can buy it or not, only whether such a barrel would require a grossly large port to run well.
If carbine gas runs better, and more smoothly, than midlength, that is how I would go. But, if carbine gas would run more violently with this setup, then midlength it is.
Docsherm, that’s pretty interesting.
The crap ammo thing is secondary. This could end up my go to rifle, and I always like such things to run anything I can find.
Used to shoot a lot of crap steel case at 3-gun, to save brass and cash. But, don’t shoot much 3-gun anymore, and steel case isn’t so cheap anymore, so why bother.
Yeah, that’s kind of why I asked. I figured the experience here would either have an answer, or a very good guess.
I have an 11" AR pistol, just cut down an m4 profile barrel to build it, it runs fine, but I had to open the port a tad. Been a couple years, don’t remember what it is now.
I also figured cutting down a 14.5" would allow custom tuning of the port, provided it wasn’t too large to begin with. From what I’m hearing, a bcm barrel shouldn’t have this problem.
Cutting a BCM 14.5" or 16" mid down to 12.5" will give you a gas port slightly too small to run unsuppressed and quite a bit bigger than optimal while suppressed.
An adjustable gas block or new gas port is recommended for dedicated suppressed use.
Well, after just seeing the last inputs on another thread about this type of barrel, I’ve pretty much decided it will be carbine gas.
Don’t want a port that is half bore size. To me, that is a grossly oversize port. I realize it runs, but my experiences in other platforms is that very large ports bring other problems with them.
I’d check out a good 11.5" barrel. I’ve got a 12.5" upper that I run suppressed and that little 1" seems to make a negative difference in balance compared to 11.5" uppers.
For those that don’t know, Gunfixr is an artist. He converted a stock saiga 12 into a beautiful select fire shotty with a 13" bbl. Works great with bird shot and high brass loads. He was also the original inventor of the upgraded gas plug for the saiga system.
Thanks for the pat, I hope you are still enjoying that saiga. I still get people saying things about the video.
I have considered the 11.5", but there is a reason for the 12". As I will be doing a custom built permanent attach suppressor of reflex design, I want the barrel past the gas block a certain way. I want no m4 cut, just straight. 750 diameter, and no 1/2 x 28 threads on the muzzle. So, I will be shortening either a 14.5", or a 12.5" barrel. Probably a 14.5", as it should have a slightly smaller gas port, and allow some tuning.
Just extra work. I’d have to turn the new gas block journal as well. Some profiles go a little under 750, so then I’d have to go 625.
If I go with a carbine gas 14.5" or 16" from a reputable maker who didn’t, or only barely overgassed it, when I cut it to 12", it will likely be OK, or only need slightly opened up. I won’t have to mess with the gas block journal at all.
Why do more work than necessary?
I will thread the area just ahead of the gas block, at whatever diameter the barrel od is true to the bore. The muzzle will be threaded only just under that od. The suppressor will essentially be a cantilever, and have less effect on poi than just hanging off a 1/2 x 28 thread. Also, instead of the barrel sleeve inner tube typical of a reflex suppressor, this will have more internal volume and less weight.
As it will be permanent, and go to 16" or perhaps 17", there will be only one stamp, and suppressors don’t need an f5 to cross state lines.
Short and handy, and at least decently quiet.
This was why I pointed out that the suppressor would be custom. While I have it mostly planned out, some of the exact details are based on final barrel and gas length. It will be a reflex unit, but if the gas block is very close to the muzzle, there isn’t much reflex room. By the same token, reflex amount has a point of diminishing returns.
So, the overall length of the suppressor is still undecided.
I got my f1 submitted, so the decision on this barrel has been made.
12", carbine gas.
As this will be a custom build, I will document it with pics. I can sure share later, if anyone is interested.
It’ll be awhile, gotta wait for the f1 to come back.