upper ar/15


when building an upper do you need a tool to align the gas system thru the barrel nut?
I was thinking of just using a punch? as you can tell it will be my 1st upper build.


If the barrel nut is timed properly you can pretty much eyeball it to get the gas block lined up right. The hole in the block is bigger than the one in the barrel so you have a tiny bit of wiggle room. You can also see where the tube enters the upper, not hard to see if it is too close to either side of the hole.

Crunchy Frog

Active Member
My first upper build used a "standard" barrel nut; we were able to "time" it by eye.

The other approach is to use a rail/but that does not require timing. The UTG Pro Rail is an example.
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The rails I've been getting from Matrix don't require timing either, just have to get the torque right.