Gas Blocks: Clamp on, set screw, other?

[tgreening]

Relatively obvious question there. I'm slowly accumulating pieces/parts for my build and that's the latest question causing smoke from my ears.

Pros/Cons of each, or is it just pick one and go?


Ar15. Yep, AR. I provided that information when I originally made this post. Yep, sure did.....

[Mrgunsngear]

AR-15?

[DnPRK]

I lake clamp on gas blocks.

[tgreening]

Yes, AR.

[Quentin2]

Pinned is the strongest.

[loose_holster_dan]

yeah, pinned do hold their place best and are always aligned, but clamp is much more convenient, since you don't have take off the muzzle brake. i have a yhm railed 2 piece gas block with bayonet lug or standard a2 pinned with bayonet lug for sale. if you're interested, pm me.

[madcratebuilder]

The pinned are the strongest but a pita to R&R. The set screw type used with dimples in the barrel hold there position very well. Another plus of using set screw type is it pulls the top half of the gas block down on the barrel making a better seal around the gas port.

[Mrgunsngear]

If you're buying it piece by piece than removing the muzzle brake usually isn't a problem and most barrels (I know some do) don't come with a pinned gas block installed. The easiest IMO would be getting a set screw block. Just ensure you dimple the barrel before you set the screw and you'll be good to go.

[CTS]

The pinned are the strongest but a pita to R&R. The set screw type used with dimples in the barrel hold there position very well. Another plus of using set screw type is it pulls the top half of the gas block down on the barrel making a better seal around the gas port.

+1. This is my preferred method as well. The Bison Armory barrel I used in my last build was already dimpled for the set screw.

[MarkCO]

Set screw and two piece clamshell type leak and dimpling barrels...not a good idea. I like the clamp style, but due to irregularities, wall thickness and such, there is still the possibility for leakage. We sat back and said..."How can we make a more reliable, no leak gas block?" Well, we figured it out and those that have used it have told us it is the best they have used. We use them on all of our upper builds.

[madcratebuilder]

Set screw and two piece clamshell type leak and dimpling barrels...not a good idea

Pretty much ALL newly installed gas blocks leak, pinned, clamped or screwed. 90%+ seal after a few hundred rounds.

Expand on why dimpling a barrel is "not a good idea"

[thesheepdog]

Daniel Defense, ADCO and others can comment that clamp on are just as strong as pinned, and are the most accurate of any type of gas block.

[MarkCO]

Our gasblocks don't leak. The ones that went through the military trials never leaked at all. All in the design.

When you dimple a barrel, you change the local stress state which can lead to accuracy issues and some irregular heat flow. Inspection of barrel interiors, especially chrome lined, has revealled that in some cases, the first point of failure and cracking of the chrome lining occurs at the point of the exterior dimpling. More often, it is at the gas port though.

[madcratebuilder]

When you dimple a barrel, you change the local stress state which can lead to accuracy issues and some irregular heat flow. Inspection of barrel interiors, especially chrome lined, has revealled that in some cases, the first point of failure and cracking of the chrome lining occurs at the point of the exterior dimpling. More often, it is at the gas port though.

With the number of gorillas working on guns these days I guess anything is possible. Drill the dimple too deep and crank down on the set screws, even drunk monkeys need work.