Colt 11.5 inch fbi barrel gas port size

**Ehgbyf** · 08-30-17, 11:54

Is the gas port the same size on the Colt fbi heavy barrel as the standard Colt 11.5 inch barrel?

**jstalford** · 08-30-17, 13:21

Grant measured one to be .069.

https://www.m4carbine.net/showthread...20#post2328220

Post 150

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**Clint** · 08-30-17, 13:32

That is a good size.

I believe the 6933s are ported quite a bit larger.

**Jwknutson17** · 08-30-17, 14:37

I prefer these 11.5s to be this, and even less. I cant see why anyone makes an 11.5 with a larger port. Even companies that offer (reduced) port sizes aren't even this small. Guess you need to cater to folks running garbage ammo these days.

**Bob Sacamano** · 08-30-17, 14:58

I have been considering one of these barrels but am yet to get a confirmation of port size. If 0.070 is acceptable for 10.5, I would expect an 11.5 to be smaller.

**titsonritz** · 08-30-17, 15:34

Originally Posted by Clint

That is a good size.

I believe the 6933s are ported quite a bit larger.

IIRC, it is .082, way too gassy.

**Ehgbyf** · 08-30-17, 17:58

I just bought one and wanted to see if I was going to have to change my setup. My current colt upper has the standard 11.5 barrel on it and on full auto with a suppressor you get a face full of gas. I run a xtra heavy buffer to keep the rate of fire down.

**Pappabear** · 08-30-17, 18:41

Originally Posted by Jwknutson17

I prefer these 11.5s to be this, and even less. I cant see why anyone makes an 11.5 with a larger port. Even companies that offer (reduced) port sizes aren't even this small. Guess you need to cater to folks running garbage ammo these days.

Its hard to imagine even trash ammo needs these blow holes. Its stupid.

PB