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Old May 23, 2019, 12:18 PM   #1
riffraff
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Best adjustable gas block for 308 AR ?

On my list of to do's I'd like to try one. Have a 16 inch mid length that's running OK via heavy spring and buffer but I think reducing gas is probably a better solution. I see a couple highly reccomended but some of the info out there is kinda dated or is geared to other calibers, surpressors, pistols, etc. I just want to tune my rifle a little better.

Not looking for inexpensive, want whatever is considered the best and most trouble free.

Thanks in advance!
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Old May 24, 2019, 04:38 PM   #2
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Seekins, Double Star, and Syrac seem to be the most common and reliable ones. Older Colt Competition adjustable gas blocks were pretty good as well. JP Enterprises makes a nice one, but it costs 2-3 times as much as the others.
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Old May 24, 2019, 05:35 PM   #3
riffraff
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Thanks! Thats funny practically none of those were on my radar, was thinking superlative arms, slr, odin, maybe gieselle may come up.

The one I read about the most is the superlative arms model, has a normal adjustment plus a gas blow off feature that can optionally be used.
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Old May 25, 2019, 06:20 AM   #4
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"The one I read about the most is the superlative arms model, has a normal adjustment plus a gas blow off feature that can optionally be used."

I'm pretty sure all the SA adjustable blocks vent the excess gas.
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Old May 25, 2019, 10:45 AM   #5
LineStretcher
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Quote:
Originally Posted by riffraff View Post
Thanks! Thats funny practically none of those were on my radar, was thinking superlative arms, slr, odin, maybe gieselle may come up.

The one I read about the most is the superlative arms model, has a normal adjustment plus a gas blow off feature that can optionally be used.
I use only JP Rifle gas blocks now. They are so easy to setup it's almost childs play. The lower half has a hole in it that matches the hole in the upper half so all you need to do is place the lower half on the barrel and align it perfectly with the gas port, mark the barrel and then install the block so that it's perfectly aligned with the port.
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Old May 25, 2019, 12:41 PM   #6
riffraff
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My main concern I guess having no experience with them is Id like something as trouble free as possible (good materials and fit, holds settings) and that I can adjust without removing the handgaurd (ie adjustment on the front).
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Old May 27, 2019, 05:14 PM   #7
riffraff
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Got a JP on the way, the 2 piece style, also grabbed a couple crush washers and a barrel clamp to make the removal of the old block and re install of the flash hider easy.
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Old May 28, 2019, 07:21 PM   #8
Jsnake711
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Ive got a seekins. With an 18" using a3.8oz. Buffer its only set to 1/2 turn out.
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Old May 28, 2019, 09:42 PM   #9
bfoosh006
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Love all my SLR's...

Please, let us know your take on the JP... thanks ahead of time.
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Old May 29, 2019, 08:15 PM   #10
riffraff
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Will do, stuffs on its way, but the real test is gonna be how I like it 2000 rounds later.

When I go to the adjustable block am going to switch back to a standard spring and buffer as well.
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Old July 1, 2019, 12:10 AM   #11
riffraff
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Originally Posted by bfoosh006 View Post
Love all my SLR's...

Please, let us know your take on the JP... thanks ahead of time.
Took me awhile to get to it, but I got the JP style that is a 2-piece clamp-on, ie secures with 6 torx's . It set me back about $120.

When I first got it I realized I made a mistake - I wanted a gas block that adjusted from the muzzle end and this actually adjusts from the side. Mock fitting showed me I should be able to get my tool on it through the existing ports on my Aero M5 handguard so I went ahead and installed it...

The hardest part was getting the gas tube pin in there, something is a pain between the pin they supply and the taper of the hole, whatever the case in the I end I found simply securing it down hard to my plastic table w/ a speed clamp worked really well as it dented the table to make a perfect cradle - then I actually used a 2 lb hammer on the punch to drive it home...

The beauty of these gas blocks are the top piece snaps in place on the barrel - when you first get it you may think initially it's the wrong size then you realize a little force and it snaps perfectly onto the barrel and can be moved but there's a good amount of friction there - this is extremely handy getting it aligned right. In the instructions they say use compressed air to verify it's well situated, I tried but felt better about my pencil marks, so ran w/ them. It lined up perfectly w/ the shoulder on my Aero barrel, no issue there either.

On my Aero M5 once completely installed I found it lines up with ports on the handle so that the allen wrench fits into the adjustment screw but the wrench does rub on one spot when turning it - if I cared I could fix this in 20 seconds by making a little divot on one edge of the guard w/ a dremel but it works just fine.

Adjusted at about 16 clicks out I get a really nice 3 o'clock ejection, there are something like 30 clicks of adjustment on this block so basically it's in the center someplace. They tell you in the instructions to start at 6 clicks out but that it is unlikely anything will cycle at a setting of 6. So far so good - provided it holds it's setting and doesn't cause problems I'm sure I'll end up with another one of these.

Last edited by riffraff; July 1, 2019 at 12:21 AM.
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Old July 1, 2019, 05:32 AM   #12
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Some advice on "roll pins" (especially the ones for the gas block, FA, and trigger guard):
buy some "ROLLED pins" vs the C-shaped "spring pins". It will make your life so much easier and prevent those nasty looking dinged up places where you tried to pound the spring pin into the tiny holes.
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Old July 1, 2019, 05:49 AM   #13
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I have lots of different ones generally go with SA these days. I have a couple of JP's in action but they are a bit of a pain to adjust IMO--adjusting the flow requires screwing the lock screw and set screw in the same hole from the side; which may not always easily line up with your guard--not to mention harder to see in the field. Nowadays I generally try to put the block right at the end of the guard and tend to get one with an easy-access front facing adjustment. Just make sure your weapon is clear!
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Old July 1, 2019, 09:15 AM   #14
riffraff
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Quote:
Originally Posted by stagpanther View Post
I have lots of different ones generally go with SA these days. I have a couple of JP's in action but they are a bit of a pain to adjust IMO--adjusting the flow requires screwing the lock screw and set screw in the same hole from the side; which may not always easily line up with your guard--not to mention harder to see in the field. Nowadays I generally try to put the block right at the end of the guard and tend to get one with an easy-access front facing adjustment. Just make sure your weapon is clear!
This particular one has a detent mechanism that holds the screw in place while allowing quick adjustments.

Thinking originally I was going to be adjusting from the muzzle I had picked up a 12 inch handguard, versus the 15 its got, to make it easier but didn't need to use it.
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Old July 1, 2019, 09:17 AM   #15
riffraff
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Quote:
Originally Posted by Mobuck View Post
Some advice on "roll pins" (especially the ones for the gas block, FA, and trigger guard):
buy some "ROLLED pins" vs the C-shaped "spring pins". It will make your life so much easier and prevent those nasty looking dinged up places where you tried to pound the spring pin into the tiny holes.
Thanks for that, will look for some next project.
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Old July 1, 2019, 09:48 AM   #16
44caliberkid
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I have Superlative and Odin Works. The Superlative has the forward facing adjustment and is easy to adjust through the front of the handguard. The Odin Works adjust from the side and are a little more work.
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Old July 1, 2019, 09:50 AM   #17
stagpanther
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Quote:
Originally Posted by riffraff View Post
This particular one has a detent mechanism that holds the screw in place while allowing quick adjustments.

Thinking originally I was going to be adjusting from the muzzle I had picked up a 12 inch handguard, versus the 15 its got, to make it easier but didn't need to use it.
Mine are pretty old--maybe they improved it. Mine still work, but they are a bit demanding to keep in tune.
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