How to properly align a gas block on AR15 the professional gunsmith way

This video shows how Modern Pawn and Guns properly aligns a gas block for barrel dimpling.

[@joshstarling5475]

Gas block genie is another way I align and so far they haven’t let me down. They’re $15 and there’s a short video shows you how to use, pretty simple and don’t take long at all.

[@TheDansana]

One of the set screws in the gas block should be inline with the gas port. Remove the grub screw completely and slide the block on the barrel rotated 180 degrees from normal. Now you can center the screw hole on the port and confirm the shoulder gap.

[@Chilidog335]

I use the same procedure. With the 90 degree mirror it gives a direct view.

[@acparish]

Sweet...answers a question that's been in my mind for awhile

[@HeartofTexasArmory]

I like that idea. @modernpawn What borescope do you use for that?

[@hairydogstail]

Yup, the only true way to verify alignment...

[@jasonm4]

Great video, proof most barrels require that 1/32" at least for a gas block. I use a credit card because it is .030" and is exactly what is needed. Most LP GB's have .120" hole. Just need a slight gap is right! Thanks Eta. Always check to make sure if you need to space .030 for the handguard cap.

[@reganerskine248]

Jason Mares this is where I got confused today.Going by the factory fitted pic a tiny gas block it’s as you say .330mm so should I set it at that?.If I set the new low profile block hard against the shoulder the holes are perfectly centred and bolt closes fine either way.Can you confirm what I should do,set same as factory one as you said above?,don’t want to fuck my gas key or tube.

[@russellstall169]

I actually like the spaghetti method

[@InfoRations]

Or you could simply make a tiny pin out of soft material like plastic, slightly longer than the thickness of your barrel. Turn the barrel, so the barrel gas hole points to the ground. Now slide your gas block over the pin and align so it drops partially into the block . Index the block location. Then roll the barrel over so the pin drops into the barrel bore and push out with a cleaning rod.....BOOM!

[@MichaelScarborough423]

Pretty much the strategy I was thinking, right on.

[@deanhenthorn1890]

Spaghetti noodle or 2mm pencil lead. I used the pencil lead trick.

[@michaelshanahan4965]

Spaghetti

[@tacticalsquash8854]

What tool are you using? I need one

[@modernpawn]

Hawk Eye shooter edition borescope.

[@jerryavalos9610]

If I had a gun shop, I would buy one, but for one time, it doesn't make practical sense and most gun shops I know do not have one.

[@norris1218]

If your gun shop does not have a basic inspection tool like a bore scope then get a new gun shop. They are idiots who don't understand proper tools.

[@emersonb5764]

I gotta disagree. Usually the hole in the gas block is so big it doesn’t matter if it’s not perfectly centered over the gas port. But what is important is that the gas tube isn’t crooked inside the receiver. So I’d rather have the gas tube perfectly aligned first and foremost. Technically this should result in a centered gas port, but you never know.

[@3dtactical475]

I use the ol credit card trick...ha

[@johnviera3884]

Yeah. Bore scope. lol. Cmon man.

[@MrChuckwagon55]

That thing costs over $700. Is there a less expensive way?

[@modernpawn]

MrChuckwagon55 the cheapest way is find a gunsmith that already has one, give him five bucks or so had have him look for you. Other than actually looking at, there is a lot of guessing.

[@johnviera3884]

Bro just eye it like they’ve done for decades. The gas block port is bigger and than the barrel port so you got some wiggle room.

[@VincitOmniaVeritas7]

You probably already solved your problem in 6yrs, but there are budget option on Ama Zon for as little as $70. I use a flexible USB bore scope called Teslong. Only downside is that it doesn’t work with iPhones (it works with Apple’s desktops/laptops though), only Android.

[@wvdave771]

That's well and good , but about as useless as the video the guy did for drilling taper pins stating "I'm using a milling machine because I have one" the most the average guy will have is a bore light , not a bore scope , so what good is the video