Why do I need an adjustable gas block?

Troy · Nov 16, 2011

Saving for a rifle that is more appropriate for 3-gun. I'm planning on having an adjustable gas block because that what everyone who knows something recommends, but why is an adjustable better than the fixed gas block on my M&P15, and since they are adjustable do they ever have to be re-adjusted?

Deathtrap · Nov 16, 2011

Reduced recoil from using only the minimum gas needed to cycle the carrier. Once it's set and locktited your done

DoctorJJ · Nov 16, 2011

Jake Burki said:
Reduced recoil from using only the minimum gas needed to cycle the carrier. Once it's set and locktited your done

If it's a brand new build, you might wanna revisit the setting after a couple hundred rounds. May not take near as much gas then.

technetium-99m · Nov 17, 2011

With light parts I have had extraction issues from too much gas. I didn't think it was possible to have this happen but turning the gas down has made the rifle run 100%. Since then loctite 620 has secured the screw very well.

Wall · Nov 17, 2011

technetium-99m said:
With light parts I have had extraction issues from too much gas. I didn't think it was possible to have this happen but turning the gas down has made the rifle run 100%. Since then loctite 620 has secured the screw very well.

I had this issue with my SBR.
It took me quite a bit to get to the root of the problem.

jtischauser · Nov 17, 2011

I have been running a lightened JP or young carrier in my Stag Arms Model 3G with a standard low profile gas block all season. So it's not necessary. I am gonna put adjustable gas blocks on my rifles this winter as they due reduce sight bounce and felt recoil. They can come loose even after loctite so there is a tad bit of possible loss of reliability when you add them. That can be said for anything that is not mil spec though.

It's fun to see the difference they make so I'd recommend trying one so u know the difference with your own eyes and shoulder.

Troy · Nov 17, 2011

Now it makes sense and sounds like a good idea. I just hope with what I eventually go with I don't have any issues, I tend to get a little frustrated and discouraged.

drmitchgibson · Nov 17, 2011

My stockade fence is mil-spec. Not too tight, not too loose.

Also, you could cross-drill the block at an angle to the gas setting screw, thread it, and put in another set screw to lock it in place. Or pin it. I actually use Loctite 680 for permanence.