Do I need an adjustable gas block for my build?

[K_Labs]

I was wondering if I needed an adjustable gas block for my build. 11.5" barrel carbine gas system. I'm trying to have as little muzzle flip as possible and will most likely want to mess with different buffer weights as well. Also already ordered my griffin M4SD linear comp.

[usmcvet]

I was wondering if I needed an adjustable gas block for my build. 11.5" barrel carbine gas system. I'm trying to have as little muzzle flip as possible and will most likely want to mess with different buffer weights as well. Also already ordered my griffin M4SD linear comp.

Is it a pistol cal gun? you might be in the wrong thread. What cal is the gun? Pistol AR's are blowback and do not have a gas tube. They're not DI but blowback like a semi auto pistol.

[K_Labs]

.223 not pistol caliber

[usmcvet]

I have two BCM 11.5" 5.56 uppers and a LMT 10.5" with FSP. No issues. Are you going to suppress it?

[K_Labs]

No I'm not. Not legal here. So I can go with a standard gas block and standard carbine buffer?

[usmcvet]

Colt and BCM ship their 11.5" guns with an H Buffer. I'd start there. Do you know what barrel you're going to use? The size of the gas port matters.
http://www.gandrtactical.com/cgi-bin/commerce.cgi?preadd=action&key=CQB-MOD011

[K_Labs]

11.5 noveske

[MistWolf]

You won't need an adjustable gas block if you get the gas port diameter right

[usmcvet]

I only have one Noveske bbl. It's on my 300 AAC. It came with the gas tube and a Noveske low profile gas block. It also came with information on what buffer to use and what loads it was tested with. It even wen in to suggest two suppressors to use what what kind of baffles they needed. Is the bbl you're looking at coming with a gas tube and gas block too? If so you'll be good to go.

[K_Labs]

It's this one. No info on that page. I'll check the paper that came with it. No gas block.
http://www.noveske.com/collections/barrels/products/cqb-5-56mm-barrel-no-gas-block

[Labayu]

I was wondering if I needed an adjustable gas block for my build. 11.5" barrel carbine gas system. I'm trying to have as little muzzle flip as possible and will most likely want to mess with different buffer weights as well. Also already ordered my griffin M4SD linear comp.

No, buffer weight and spring rate alone will do all you need.

Right now I have my 10.5 tuned with a stock weight CS recoil spring and an H2 buffer it tosses the brass from civilian 55gr bulk ammo to the rear at the very edge of excellent ejection bordering on too much buffering. It shoots perfectly with 62gr Green Tip and 69gr SMKs. If I added the sprinco "blue" spring it would barely toss them out of the ejection port and have the softest cycling action possible for that barrel length and gas system.

If I added a Precision Armament M4-72 compensator I would be looking to make sure I didn't have a squib load if I didn't have a reactive target.

https://youtu.be/3FD-Rou9-9A

[Clint]

I was wondering if I needed an adjustable gas block for my build. 11.5" barrel carbine gas system. I'm trying to have as little muzzle flip as possible and will most likely want to mess with different buffer weights as well. Also already ordered my griffin M4SD linear comp.

A good way to answer that question is to measure the gas port in the barrel.

[K_Labs]

Ok Gas port measures .074

[Clint]

That is a good size.

It should be able to run very well with an H2 buffer.

[K_Labs]

Is the ST-T2 ok?

[usmcvet]

Good info here:

https://www.m4carbine.net/showthread.php?6827-Buffers-amp-Springs


I answer this question without saying a word...

http://ar15barrels.com/tech/buffer-construction.jpg

http://ar15barrels.com/tech/buffers.jpg

http://ar15barrels.com/tech/stocks.jpg

[Clint]

Is the ST-T2 ok?

These days, there are several, much better choices available.

[K_Labs]

So could I go with a H2 and a JP spring?