Brownells Gun Tech™ Caleb Savant shares some nuggets of wisdom about AR-15 gas block alignment. A misaligned gas block is one of the most common causes of malfunctions on AR-15 rifles, but there’s good news. It’s not difficult to get that gas block properly aligned. With the aid of a cutaway, Caleb explains how the gas port is drilled into the gas block. The gas port in the barrel is actually smaller than the one in the gas block, so a little misalignment between the two isn’t a problem. This also means the gas block can be pushed all the way to the barrel shoulder OR left with a smidge of space between it and the shoulder to account for the space normally taken up by the handguard end cap. Either way is fine. The dimpling for the gas block setscrews on the outside of the barrel should always be drilled exactly opposite from the gas port. Are you planning to drill the dimples yourself? Caleb has a valuable tip for you!
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You are right ONLY IF the barrel maker AND the gas block maker places the gas port holes in the same distances from the shoulder (for the barrel) and the rear face (of the gas block). I have encountered where the both had different distances used for their gas holes. For me, the best solution is to use a dimpling jig which indexes the dimple by the use of the bolt that sets into and centered in the gas port which then allows you to center to dimple the barrel. That way, you can be sure that the gas block hole is directly on top of the gas port in the barrel. Also, once the dimple is set, then the second set screw can be removed and the hole's position marked on the barrel. Then you only need to align the dimple jig over that mark to properly dimple the barrel for the second dimple. This takes ALL and any guesswork out and ensures a properly installed gas block.
I have an ar that's under gassed and I've tried everything I'm so close to CUTTING the buffer spring
Why would they not just standardize it? Machine one side flat to interface with a flat side of the barrel and there would never be an alignment issue. Poor design choice here.
Why does this gas block have a hole at the top that is totally see through? Is that for demonstration purposes?
Bro your haircut is fucking awesome lol
Helpful video!
Excellent video bud
I have a 5 inch barrel. I was wondering what's the best gas block and tube to get to build a 556 pistol
Should I use loctite in the set screws? And blue or red? Thanks!
I appreciate you guys offering a technical support phone number
Very helpful. Thank you!
Thank you for this.
Real quick question I've bilt my first ar and the bolt wont cycle corectly as in the bolts not coming far enough back im assuming I didnt Aline my gasblock or tube corectly besides that anyone else think it could be something else im open to opinions
I just dont trust dimpling. Why not just drill and pin?
Quick question, I build at ar but leaks a bit for the gas block roll pin is that normal??? Anyone is having this problem, the ar is running excellent just i don't like the small gas leak🤔🤔😬🤷♂️
But how do i ensure its aligned from right to left instead of forward and back? Is eye ball alignment good enough?
Very good information. Thanks
Dimpling is designed for regular old screws. But with the new fangled “cupped screws”, does dimpling actually work against you? Cupped screws are designed for a round flat surface.
You got a pretty mouth boy
This video was perfect. Was worried because I put my gas block all the way to the shoulder.
On one of my builds I was not able to install the roll pin completely through the second hole before the pin began to flatten out.
I do have a solid installation and the weapon operates properly.
Do you see any problems with leaving it as is or should the pin be replaced?
It’s a stainless steel gas block and I’m not confident of the alignment of the two roll pin holes.
I took his advice and my gasblock blew off….🙄
great videos
I did something unconventional and it worked out for me. I just plugged the end of the barrel and blew through it and the dimple on my barrel was dead on. You can move the block and know pretty quick if it’s off or not. Set it and retest.
Good video.
If my barrel does come barrel dimple does it matter? Can I still use any low profile gas block on a mid length. Ballistic advantage barrel 16inch
It blows my mind that this is an issue for people, dimple or not. This is just about the simplest part of an upper build. Oh well, to each his own.
When I put together an AR, I put the gas tube into the gas block and then slide everything on the barrel and into the receiver. I almost tighten the screws then put a length of rubber hose over the gas tube inside of the receiver. I position the gas block close to the position I think it should go and then I blow through the hose and listen to the air escaping and by the resistance I feel blowing through it I find the best place to tighten the screws. I put Rocksett on the screws one at a time and tighten each. I had a gas block and rifle that just wouldn’t work until I did this.