ISO: an adjustable gas block

[CRAMBONE]

So I am getting all of my parts together for my SPR build and have hit a speed bump. I will be using a Rainier Arms 18" rifle length Ultramatch barrel, a 15" Geissele MK4 and a Griffin Armament SPR can. According to Geissele's website the MK4 has an ID of 1.35''. I cannot find an adjustable gas block that will fit inside.

I had settled on the Syrac but the company seems to have gone away. Rainier suggested the Superlative Arms AGB but it has a height of 1.383", and I'm not sure if I would want the gas "bleed off" it has. SLR's Sentry 7 is 1.40" in height.

What else is out there? Have I over looked anything?

[elephantrider]

SLR Sentry 7 should fit w/o issue. There is plenty of room inside a Geissele SMR. The 1.40" dimension of the SLR does not interfere with the inner 1.35 radius of the Geissele.

[CRAMBONE]

SLR Sentry 7 should fit w/o issue. There is plenty of room inside a Geissele SMR. The 1.40" dimension of the SLR does not interfere with the inner 1.35 radius of the Geissele.

I was wondering if Geissele was listing the ID that way and not including the complete up and down available space. I have an email out to them asking this question, but have not heard back yet. And I am not home to be able to measure it myself.

[dmd08]

I have an SLR sentry 7 inside a Geissele Mk4. It works fine.

Sent from my SM-G935V using Tapatalk

[Slippers]

I have an SLR Sentry 7 inside a MK4 and the button head screw that secures the detent on the gas block has only a tiny amount of clearance. Less than 0.020" in my case. I ground down the edge of the screw to open it up to 0.050" or so to be safe.

[CRAMBONE]

Just received this from Geissele. Looks like there is enough room for the agb.

http://i.imgur.com/bKnCGoU.jpg

[CRAMBONE]

Also, looks like everyone is running the SLR option. How are they working out for you guys? Clamp on or solid?

[Fatorangecat]

I have used a clamp on sentry 7 under an MK4 and MK8.

[elephantrider]

Also, looks like everyone is running the SLR option. How are they working out for you guys? Clamp on or solid?

SLR Rifleworks Sentry is the way to go. If you look around here, you will find almost entirely positive reviews. BufordTJustice probably has the most experience with them, or at least has posted the most about them. Unless something newer and better has hit the market, you likely wont find a better adj. gasblock. Get the "solid" aka setscrew version which can be cross pinned over the clamp style. Set screw/cross pin is typically a better installation than a clamp on.

[MistWolf]

The clamp on design has a tendency to break the clamp screws. I use the set screw style, no pinning and it has never worked itself loose and I've gotten it plenty hot, especially now that I'm running a suppressor

[CRAMBONE]

Awesome. Thank you guys. Rainier is currently out of stock.