Low Profile Gas Block Clearance

[gimpy]

How much clearance should I accept at a minimum? Put together a URGI type rifle with Geissele Mk16 rail and a Badger Mk12 gas block. Seems to be a little less than 1/16” between the bottom corners of the gas block and the inside of the rail.

Is this close enough that I should worry about interference when firing? I have a KAC gas block that should be slightly lower profile.

 

[Neurotic]

0.0625" should be fine, especially if the gas system is mid-length or shorter and the barrel isn't a pencil profile.

I try to stay above 0.040". I did run a mid-length pencil profile barrel at ~0.020" and didn't seem to have an issue. I ultimately changed out the handguard for more clearance, but didn't see a difference in grouping.

 

[gimpy]

0.0625" should be fine, especially if the gas system is mid-length or shorter and the barrel isn't a pencil profile.

I try to stay above 0.040". I did run a mid-length pencil profile barrel at ~0.020" and didn't seem to have an issue. I ultimately changed out the handguard for more clearance, but didn't see a difference in grouping.

The barrel is a 14.5” Proof CR barrel, so I’m assuming I’ll be fine with that low clearance, especially since what I’ve read implies that maximum barrel movement doesn’t occur until after the projectile is out of the muzzle.

 

[padom]

Didnt your Geissele come with their super low pro gasblock?? I use them on all my AR's and have the smallest profile of any gasblock Ive used...

 

[gimpy]

Didnt your Geissele come with their super low pro gasblock?? I use them on all my AR's and have the smallest profile of any gasblock Ive used...

The mk16 URGI rail didn't come with a gas block. I have to agree. The one time I used a Geissele gas block, it was extremely low profile

 

[unclemoak]

Didnt your Geissele come with their super low pro gasblock?? I use them on all my AR's and have the smallest profile of any gasblock Ive used...

G gas blocks aren't exactly low profile from my perspective. They have a fair bit of added bulk on the bottom where the set screws are and the escutcheons for pinning.

I actively discourage people from G gas blocks as they tend to have a larger than nominal bore and are prone to leaking, which can cause cycling issues in some guns.


SLR or a Badger TDX are much slimmer in profile.


TDX:

SLR