Gas block for 11.5" Colt FBI barrel

[coolcraigster]

Almost done with this build just trying to figure out gas block situation. Using Colt 11.5 FBI barrel. Of coarse it has the FSB pinned and I know I'm probably gonna get beat down for this but I'm installing SLR adjustable gas block since I will be adding suppressor later. I've never had an issue with the SLR AGB. Question is I was gonna use a set screw gas block and dimple the barrel. Of coarse the barrel has the milled slots for the FSB pins and when I install my dimple jig the rear hole directly under gas port where I need to put dimple is half barrel and half pin slot if that makes sense. Should I just dimple for the front set screw and leave the rear alone or use clamp on? Gas block will be totally covered by handguard. Thanks

[GH41]

SLR used to make gas blocks with different setscrew hole spacing. Depending on which one you have going longer or shorter may get you off of the pin bore.

[coolcraigster]

SLR used to make gas blocks with different setscrew hole spacing. Depending on which one you have going longer or shorter may get you off of the pin bore.

I'm pretty sure the rear set is still directly under gas port and the front set screw is moved. Not 100% but I will investigate. Thanks

[coolcraigster]

Just checked with SLR and the rear set screw will still be in the same location and the front set screw is moved. So I will still be in the same boat either way.

[tehpwnag3]

You mentioned a clamp on. Do you already have the set screw gas block?

[coolcraigster]

No I don't have a gas block for it yet. I wanted to get some advice before I ordered one.

[tehpwnag3]

Get the clamp on version. I'd want the tightest seal afforded by the rear screw, especially with a can.

[coolcraigster]

Get the clamp on version. I'd want the tightest seal afforded by the rear screw, especially with a can.

Thats the direction I was leaning. It will be completely covered by the handguard so I shouldn't have to worry about it moving. I've never had a clamp on move before.

[tehpwnag3]

It should be fine under the rail. You may want to check inner dimensions to make sure it will fit inside your chosen rail AND with the accessories you'll be putting on it.

[Combat_Diver]

Almost done with this build just trying to figure out gas block situation. Using Colt 11.5 FBI barrel. Of coarse it has the FSB pinned and I know I'm probably gonna get beat down for this but I'm installing SLR adjustable gas block since I will be adding suppressor later. I've never had an issue with the SLR AGB. Question is I was gonna use a set screw gas block and dimple the barrel. Of coarse the barrel has the milled slots for the FSB pins and when I install my dimple jig the rear hole directly under gas port where I need to put dimple is half barrel and half pin slot if that makes sense. Should I just dimple for the front set screw and leave the rear alone or use clamp on? Gas block will be totally covered by handguard. Thanks

FYI when NSW Crane takes the FSB off for Mk12 gas blocks, they do the same thing you describe. (10.3" and 14.5" URG)

CD