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Gas Port Size 11.5/12.5 Suppressed

KevinU

Sergeant
Full Member
Minuteman
Jun 14, 2009
482
54
Colorado
Looking at having either a 11.5 or 12.5 223 barrel chambered that I will only shoot suppressed/TBAC Ultra 7. 11.5 carbine length gas, 12.5 midlength gas. Handload 69SMK's, 73ELD's or 77SMK's. Suggestions for a gas port size.

Thanks
 
I'm interested in this as well, since I am in the process of assembling a 10.5"/carbine gas upper. The barrel distributor states: Barrels are ported to work with standard carbine springs and buffers when used with Normal ammo producing 54000psi, but since I plan on running a can, I figure that that kinda throws a wrench in the works. I have an adjustable gas block and both carbine and H2 buffers available, so hopefully I can get the thing to run.
 
Sionics makes Reduced Gas Port & Extremely Reduced Gas Port barrels. I run the RGP 11.5” suppressed full-time and it runs great. Search around m4c.net forum for those barrels, and SBR gas port size in general, and you’ll have days worth of reading...or just go ahead and get the Sionics because after reading you probably will anyways.

Black River Tactical is another solid option with dedicated full-time suppressed barrels.
 
Go with the smallest size you can get. Enlarge as required for your load.

Or... Use your adjustable gas block. So what if it locks up?!?
 
I'm not associated with MSTN other than being a very satisfied customer, but I've been extremely happy with the barrel I bought from Wes almost a year ago.

 
I'm interested in this as well, since I am in the process of assembling a 10.5"/carbine gas upper. The barrel distributor states: Barrels are ported to work with standard carbine springs and buffers when used with Normal ammo producing 54000psi, but since I plan on running a can, I figure that that kinda throws a wrench in the works. I have an adjustable gas block and both carbine and H2 buffers available, so hopefully I can get the thing to run.
If you know what size port you want add it in the additional comment box.
Every can will produce a different amount of backpressure, Surefire very little something like a YHM or Dakota made for bolt guns will make a bunch.
 
If you know what size port you want add it in the additional comment box.
Oh, I already have the barrel in-hand; I am just trying to figure out what combination of parts I'll need to get it to run. A buddy has a RDIAS, so I intend for this upper to spend some time as a bullet hose. As it is, I have the barrel, an SLR adjustable gas block, and one of the gee-whiz BCGs from Cryptic Coatings. As mentioned, I have regular carbine and H2 buffers (well, Armaspec Stealth recoil setups, similar in concept to JP SCS) available. It'll spend time both unsuppressed and running a Specwar 7.62, and the diet will likely be mostly milsurp.
 
Oh, I already have the barrel in-hand; I am just trying to figure out what combination of parts I'll need to get it to run. A buddy has a RDIAS, so I intend for this upper to spend some time as a bullet hose. As it is, I have the barrel, an SLR adjustable gas block, and one of the gee-whiz BCGs from Cryptic Coatings. As mentioned, I have regular carbine and H2 buffers (well, Armaspec Stealth recoil setups, similar in concept to JP SCS) available. It'll spend time both unsuppressed and running a Specwar 7.62, and the diet will likely be mostly milsurp.
This is always a consideration when building and choosing parts. If you want the thing to run non stop after it gets hot, dirty and dry set it up to run a H2 buffer, full weight M16 carrier and RED spring(Sprinco) or SSS spring so there is more momentum to push the BCG forward and at the same time it will need more gas to shove the BCG to the rear. If it's a duty rifle it's OK if it is a little over-gassed and tossing cases straight out at 3 O'clock.
 
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Can anyone give me a simple understanding of the ideal sizes of gas tubes for different lengths of barrels such as 11.5, 14.5, 16? and also what the happy medium is to be able to shoot suppressed and unsupressed and have good reliable results? Thanks
 
The longest gas system you can get to work. 10.5 carbine, 11.5 carbine plus 1, 12.5 C+1 or mid, 14.5 mid to KAC, 16 KAC to intermediate, 18 rifle.

100% suppressed, 11.5-12.5 mid, 14.5 intermediate, 16” rifle.