Adjustable Gas Block?
I have an AA upper and 20" barrel and bolt with a rifle length gas system on order but I am trying to decide on a gas block. I plan on shooting 100gr - 130gr bullets. Do I need an adjustable gas block? Could it be tuned to reduce recoil?
Thanks for your input.
You don't have to have one but they are nice, particularly if you reload. It will save a lot of wear on your brass.
Mine tended to unlock the bolt while pressure was still pretty high in the barrel. That made for a hard ejection and very dirty brass.
I shoot bullets of 100 grains up to 130 grains without readjusting the gas block in a 20 inch barrel.
I adjusted mine with 123 grain bullets so that it reliably ejects and locks the bolt back.
I was surprised to find that I needed to open it up more for 100 grain bullets. So be sure and test it with all the bullet weights you want to shoot.
Thanks Rick. It sounds like you have pretty much the set up I am thinking about going with. Let me ask you this, what handguards did you with? I am still trying to decide whether to go with standard rifle length and leave the gas block exposed, or to go with the extended rifle length and cover the gas block.
Also any opinions out there on the Syrac adjustable gas block? I like the idea of having the detent instead of using locktite on the adjustment screw.
I would not build one without it. Every grendel I have seen is over gassed (read tries to unlock to early like the post above). I believe this is why people bust bolts. That is my opinion.......and you know what those are like.
Hello and welcome!
Originally Posted by outbreaker
I agree. They are money well spent on a Grendel IMO.
I haven't seen a real need on builds with rifle-length gas systems, but adjustability is definitely recommended on most midlengths.
Has anyone tried the paladin machine 3 position gas block? I was wanting a 3 position block for when I get my suppressor
Yes, but not with a suppressor.
They can make it to fit your needs, but the finish isn't as good as something like a Noveske switchblock.
I have the Daniel Defense Light Rail.
Originally Posted by kbarnes12
I had a flip up front sight on the old gas block that I really liked that I wanted to keep, so I tried one of the gas tubes with an adjuster on it. It didn't work out. I had two and both started leaking after about 50 rounds.
I figured with all the holes in the DD rail I'd be able to get at the adjustment. No dice. I ended up drilling out a larger hole to get to it, then ended up trashing the adjustable gas tube anyway.
There's no way to tell if you can get to the side adjusters with your rail unless somebody else has the exact same setup and you know it will work.
I haven't used the Syrac, but with it's front adjustment you should be able to get at it with about any floating hand guard, unless you get a very long one.
I have a JP with the adjustment on the side and the DD rail doesn't cover it up. Just has the Allen screw, but I rarely adjust it once it's set.
I prefer the clamp at the bottom type blocks (split bottom). They just seem more secure to me, and they are easier to put on. Keeping them lined up as you tighten is a little harder, but not much.
Last edited by RangerRick; 04-25-2012 at 05:32 AM.
I have a PRI Adjustable gas block. It came with a rifle length, strait gas tube. I have a rifle length hand guard and I can easily get to the adjustment on its side.