If I remember correctly, I am supposed to put the barrel into a receiver, install the bolt and the muzzle device, and then use a dowel down the barrel until it hits the bolt face to get the barrel length. Problem is my upper has not arrived yet. Can I stick the bolt face into the barrel and then do the same procedure? It I am at 16" I should be good right? Going towards the city is where I can have the muzzle device pined, so hoping this way of measuring will work.


Edit:

Just measured it this way and came up wit 16 -1/16"

Yup, just engage the lugs and measure. Muzzle device will be pin/weld, correct? A 1/16th is worth a measure twice

I'm assuming your goal is to verify the muzzle device is long enough to reach 16" prior to pinning? You don't need the barrel installed in the upper receiver to measure barrel length. Just lock the bolt into the barrel extension and drop in a dowel.

Attached File


From the NFA handbook.

Yes, you can put the bolt into the extension, lock it in place, and then measure it with the dowel. It's essentially the same thing they would do measuring it with the receiver in place.

I would recommend have the complete bcg so that way it can rotate and lock into place. You can use a 1/16 punch to lock the gas tube in place temporarily so that you can align the bolt carrier just right and lock it in. You don't want the bolt spinning and fall out as you're doing this.

It's always recommended to have a .1 inch clearance to account for any mishap with the bolt face measurement. If it is exactly 16" there could be wiggle room and you'd be hit with a technicality.