Aligning clamp on gas block to port?

[Napeequa55]

First time using a clamp on gas block instead of the set screw and dimple. Its a Superlative Arms adhustable.

What's the best method to align the clamp on block to gas port?

I ended up ordering a shim designed for barrels when not using the obsolete the handguard endcap.

Just curious how people are doing this on AR builds without a shim.

Thankd

 

[Im2bent]

I use a bore scope to align the gas block

 

[EMorr]

Well I'm not sure how the pro do it but I used 2 methods at the same time on my builds as a redundancy and all my guns run just fine.

Method 1) Draw a pencil line straight down the center of the gas block using a straight edge and then draw another line straight down the bore centerline of the barrel where the gas port is, when the lines on the barrel and gas block line up, so should the ports.

Method 2) Install the gas tube in the gas block and the BCG in the upper and then slide the gas block on the barrel until the gas tube interfaces with the BCG. It becomes pretty obvious if the alignment is off even a little and when I combine this with the first method I've had great results.

 

[rpoL98]

First time using a clamp on gas block instead of the set screw and dimple. Its a Superlative Arms adhustable.

What's the best method to align the clamp on block to gas port?

I ended up ordering a shim designed for barrels when not using the obsolete the handguard endcap.

Just curious how people are doing this on AR builds without a shim.

Thankd

i use a feeler gauge (instead of a shim). the kind used for setting valve lash.

 

[Desert_Racer]

Well I'm not sure how the pro do it but I used 2 methods at the same time on my builds as a redundancy and all my guns run just fine.

Method 1) Draw a pencil line straight down the center of the gas block using a straight edge and then draw another line straight down the bore centerline of the barrel where the gas port is, when the lines on the barrel and gas block line up, so should the ports.

Method 2) Install the gas tube in the gas block and the BCG in the upper and then slide the gas block on the barrel until the gas tube interfaces with the BCG. It becomes pretty obvious if the alignment is off even a little and when I combine this with the first method I've had great results.

I have used method 1 mentioned above for years, and have never had a problem.

 

[Simonsza1]

Brownells sells alignment pins. There little orange plastic pins that align the holes perfectly and keep it there while tightening. Then you break the pin with a cleaning rod and your done. There so simple to get perfect even a cave man can do it.

 

[supercorndogs]

I eye ball them. I haven't missed one yet, in a bunch. ITs not a very hard game to play.

 

[roostercogburn98]

I pay someone 64.37 to install them.

 

[rpoL98]

I pay someone 64.37 to install them.

wow, for that kind of money, I'd verify the hole sizes with pin gauges, both barrel and gas block, measure the gas port set-back from the shoulder with calipers (barrel & GB), calculate the correct set-back taking into account the GB hole being bigger than the barrel gas port, get out the right feeler gauge to insure the correct set-back, draw the afore-mentioned lines, do the install using a small flat piece of alum in the clamp-on gap, reverse the screws to apply very slight expansion of the block (maybe 1/8 turn) so that it slips on without scratching any of your expensive barrel, verify alignment with a bore scope and flashlight into the gas tube hole. probably have to take bore scope pics and send them to your fon as proof of alignment. There's probably some additional steps that the real pros use that are trade secrets that I'm overlooking (my nick-name is bubba), or I plumb Jethro-forgot.

or maybe I wouldn't because of liability, no insurance, etc.

 

[roostercogburn98]

wow, for that kind of money, I'd verify the hole sizes with pin gauges, both barrel and gas block, measure the gas port set-back from the shoulder with calipers (barrel & GB), calculate the correct set-back taking into account the GB hole being bigger than the barrel gas port, get out the right feeler gauge to insure the correct set-back, draw the afore-mentioned lines, do the install using a small flat piece of alum in the clamp-on gap, reverse the screws to apply very slight expansion of the block (maybe 1/8 turn) so that it slips on without scratching any of your expensive barrel, verify alignment with a bore scope and flashlight into the gas tube hole. probably have to take bore scope pics and send them to your fon as proof of alignment. There's probably some additional steps that the real pros use that are trade secrets that I'm overlooking (my nick-name is bubba), or I plumb Jethro-forgot.

or maybe I wouldn't because of liability, no insurance, etc.

All that for 64.37!! That’s a real bargain when you add it all up.

 

[rpoL98]

make sure that alum plate doesn't hang into the gap and scratch your very expensive barrel.

 

[Powder_Burns]

I use an end cap from the old carbine handguards made into a gauge for the spacing. i make a witness mark with pencil for tdc on the barrel and on the edge of the gas block. line up the pencil marks, remove the gauge, tighten bolts, wipe pencil marks off.

 

[supercorndogs]

Oh no, don't scratch an AR-15 barrel. You spent so much getting it painted to match your fingernail polish.