Validated Accuracy Impact of Pinned vs. Clamp-On Gas Blocks?

[Will_Power]

Guys,

I've read in numerous places that the clamp-on gas blocks are the best bet for wringing all the accuracy that you can out of your AR, but that getting the gas block taper pinned is the best choice for durability. Trouble is, everything I've read seems to be one line replies or anecdotal reports.

I've got a build in the works that I am planning on taking into the field and hunting with. As such, getting the gas block pinned seems appealing.

Was curious if any of you old hands can speak to the potential impact to accuracy I'd see if I went pinned instead of a clamp-on block.

 

[1slow01z71]

Never done a comparison buy I can say my pinned noveskes shoot well below moa so I'd say if it is hurting accuracy it aint much. Most of my builds use gas blocks with double set screws. In my opinion pinning the gas block is overrated as long as youre using a quality gas block with dual set screws with loctite on them and atleast one dimple in the barrel for the set screw to seat in. You'd be surprised how many of the commercial builds do not have a pinned gas block. Im not a professional AR builder so take my opinion for what it's worth.

 

[rjacobs]

Doesn't matter to me either way and I've never been able to tell an accuracy difference. I'm also not a pro builder but have built enough uppers for local guys and I've built with pinned and set screw gas blocks and so far nobody has complained which ever way. I also have never invested in the jig to drill and pin gas blocks/barrels that don't come from the manufacturer that way. It's something I have looked at a few times, but just never pull the trigger on.

Now I will not use a clamp on type, I just don't trust them.

 

[MLC]

I use a PRI gasblock that has two set screws on the bottom.
My 16" mid length AR will do half MOA and has shot under 3" at 700 yards.

YMMV

 

[hlee]

Unfortunately, I think what you are going to see are anecdotal reports of accuracy difference (or not) because it is very difficult (impossible?) to get enough rifles together to do an actual experiment. And, while you could compare a clamp on gas block to a set screw gas block on the same barrel, I am not sure that most would be able to deconvolute the variables of testing multiple barrels.

I have read that a clamp on gas block evenly distributes the clamping forces, and are less likely to deform the bore of the rifle than a set screw GB.

My lr308 has a clamp on GB and a 1.5" group at 100 yards is giant. Sub-moa is much more common with FGMM and hornady match. And, I have an oracle in 223/5.56 that hasn't printed 5 shots at 100 yards that can be covered with a baseball cap. It has a set screw gas block. If only I could swap out the gas block and make everything right with the world...

 

[Ballista One]

There is no way to "validate" which set-up is more accurate. Way to many variables....

 

[tylerw02]

I've seen very accurate examples of both. Go with a good barrel and good ammunition and it will be more than adequate in the accuracy department.