Gas Block Alignment

[kmk1012]

Ok, I've put several AR's together over the years and still don't know the correct way to do it. Are new barrels gas ports still spaced for the end plate associated with drop in handguards or are they spaced for a free float design. Meaning, the distance from the bolt face. Also, what is the proper procedure for aligning the gas block from right to left? I guess I've gotten lucky the last ten or so times but am struggling with the new barrel for my AR10.

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[powermad]

I dimple the barrel.
Dimple jigs are about $30

 

[kmk1012]

I dimple the barrel.
Dimple jigs are about $30

Ok, didn't realize such a thing was made. I'll look and see if they are universal or one needed for each diameter of barrel. This one is a .936"

 

[powermad]

I have them in .625 and .750
My .850 journal barrel came dimpled so I didn't have to get one for it.

 

[powermad]

First hit.

.936 Dimpling Jig

slrrifleworks.com

I have KVP ones

 

[Saladfarmer]

And there's always the spaghetti trick. Don't knock til ya try it. Works better than you know if you haven't had to do it. I had to do it once after someone used their fancy bore scope and said it was good to go only to find out it really wasn't.
But yeah.. Dimple that barrel and make life easy.

 

[P7M13]

If the barrel has been nitrided, do not bother trying to dimple it.
I use a tungsten scribe on both the barrel and gas block, and then line them up.

 

[kmk1012]

And there's always the spaghetti trick. Don't knock til ya try it. Works better than you know if you haven't had to do it. I had to do it once after someone used their fancy bore scope and said it was good to go only to find out it really wasn't.
But yeah.. Dimple that barrel and make life easy.

I'm always interested in cheapskate tricks, it allows me to sink $1000 into $500 guns all the time . On a serious note, I'm listening about the trick.

 

[Caveman Jim]

If the barrel has been nitrided, do not bother trying to dimple it.
I use a tungsten scribe on both the barrel and gas block, and then line them up.

I use a fine point sharpie, it twerks for me.
I make sure I find the center on the GB, scribe to gas tube hole and line up to a mark on the barrel.

 

[Saladfarmer]

I'm always interested in cheapskate tricks, it allows me to sink $1000 into $500 guns all the time . On a serious note, I'm listening about the trick.

OH. Alrighty. hold the barrel with gas port facing up. Take a piece of UNCOOKED spaghetti. Stick it in the hole and break it so it is flush with the exterior of the barrel. Now slide the gas block over ball parking the alignment. Now flip the barrel over so the gas port hole is facing the ground and look down the barrel, preferably with some light on the other side of the barrel so you can see in . Once the spaghetti "disappears you know you found the right alignment. Give a little spin to tighten up the connection to the barrel. Spin the barrel right side up again. if you see the spaghetti you know you're right on. If you don't you're a smidge off. lightly maneuver the alignment til you do and repeat accordingly...
To remove the spaghetti when done, meaning the spaghetti move freely in and out of the gas block. with the barrel oriented so you can see the spaghetti, point the muzzle at the ground and put a cleaning rod through and it should break in two. pick up the pieces make sure there's two and it's the right amount. inspect the barrel .
Works like a charm.

 

[msgriff]

You can DIY a dimpling/alignment jig if you have an old set-screw gas block of the appropriate diameter that you're willing to easily modify.

 

[kmk1012]

OH. Alrighty. hold the barrel with gas port facing up. Take a piece of UNCOOKED spaghetti. Stick it in the hole and break it so it is flush with the exterior of the barrel. Now slide the gas block over ball parking the alignment. Now flip the barrel over so the gas port hole is facing the ground and look down the barrel, preferably with some light on the other side of the barrel so you can see in . Once the spaghetti "disappears you know you found the right alignment. Give a little spin to tighten up the connection to the barrel. Spin the barrel right side up again. if you see the spaghetti you know you're right on. If you don't you're a smidge off. lightly maneuver the alignment til you do and repeat accordingly...
To remove the spaghetti when done, meaning the spaghetti move freely in and out of the gas block. with the barrel oriented so you can see the spaghetti, point the muzzle at the ground and put a cleaning rod through and it should break in two. pick up the pieces make sure there's two and it's the right amount. inspect the barrel .
Works like a charm.

Genius!!! I know what I'm doing tomorrow, thank you!

 

[kmk1012]

You can DIY a dimpling/alignment jig if you have an old set-screw gas block of the appropriate diameter that you're willing to easily modify.

I happen to have an extra .936" gas block that if not ruined may turn into another build, LOL. If the spaghetti trick doesn't work I'll look into modifying it.

 

[titsonritz]

First hit.

.936 Dimpling Jig

slrrifleworks.com

I have KVP ones

This the one I have.

Do yourself a favor and only dimple the barrel in one spot opposite the gas port, use knurled screws, degrease everything and use red Loctite to secure the screws.

 

[titsonritz]

 

[kmk1012]

@Saladfarmer, the spaghetti trick worked wonderfully! Thank you for sharing that trick. I'm more reflect than professional tech and I will use this alway now.

 

[Saladfarmer]

@Saladfarmer, the spaghetti trick worked wonderfully! Thank you for sharing that trick. I'm more reflect than professional tech and I will use this alway now.

Sweet! The 'ol Cletus trick worked. Hats off to you for understanding my explanation without pictures. Wish I knew who to give credit for me knowing about it, but "merican ingenuity at work without duct tape is always a good value.

 

[titsonritz]

Sweet! The 'ol Cletus trick worked. Hats off to you for understanding my explanation without pictures. Wish I knew who to give credit for me knowing about it, but "merican ingenuity at work without duct tape is always a good value.

It is an old trick that has been around for years, Brownells even sells (or at least use to) a fancy version.

https://www.facebook.com/Schoolofth...alignment-method-using-pasta/405064776841669/

That said, there is more to proper installation of a gas block than alignment. I have seen several cases where a LPGB w/o a dimpled barrel have shifted out of alignment from use or impact shutting the gun down.

Do what you want but all my LPGBs under a handguard get a dimpled barrel, knurled set screws and red Loctite. That is how BCM, SIONICS and SOLGW all do it so it is time proven. All exposed gas blocks get pinned. I'll never use a clamp-on gas block.

 

[Nosferatu]

@Saladfarmer, the spaghetti trick worked wonderfully! Thank you for sharing that trick. I'm more reflect than professional tech and I will use this alway now.

It's no good unless you celebrated with a proper pasta dinner.

 

[kmk1012]

It's no good unless you celebrated with a proper pasta dinner.

Had some "Jessie Kelley" burgers and suddenly salad, hope the noodles of a different shape count!