Gas block on an AR 15

[k4swb]

Is there any way to make sure that you have the gas block exactly positioned in the correct spot before you touch off a round?

I recently changed out my stock handguard with a different one that required a low profile gas block that locks on with set screws and I'd prefer to know it is correct before I take it to the range so I don't have to do smithing at the range.

 

[troy fairweather]

blow down the barrel with a fired round in the chamber.

 

[badkarmamib]

Use a pencil to mark the barrel shoulder in line with the center of the gas port. Use a pencil to mark the rear face of the gas block in line with the center of the hole. Line up the marks, keep the block off the shoulder 1/32" if you are not using a handguard cap. Tighten, and shoot.

 

[Chuck R.]

On a set screw gas block one set screw is directly counter to the gas port.

You can use that set screw hole to align the block to the gas port, mark it with a pencil etc on the fwd edge, then rotate 180 degrees.

I bought a gas block jig, which makes it a snap, but I've done multiple barrels with it. I also dimple my barrels:

https://slrrifleworks.com/index.php?route=product/product&product_id=579

 

[Varminterror]

Empty case with fired primer in the chamber, blow into the muzzle as you move the block around. You'll feel the resistance change. No way to fake it that way.

 

[k4swb]

Thanks for all the suggestions. If I had been thinking I might have come up with something easy like these.

I'm bad about over thinking things.