Re-thread Barrel?

I've threaded on a blackout directly to a BCM barrel w/ no issues. If concerned, have a good smith check it (bet you $10 he'll clean it up a little and tell you is was a little off, which it probably is).

Cap,

It can be that simple, but MtnCreek offers some good advice. A good smith can check the concentricity of the bore for you. That is the problem more often than the threads. If the bore is not centered in the barrel, baffle strikes are likely. Folks like Mike Stannard at Tornado Technologies have the equipment to ensure the bore is centered in the threaded end. Others do as well; you can probably get some recommendations on here.

I would argue the "most firearms" part of the original statement. A lot don't have a problem. Some do.

I had a baffle strike on one of my cans a while back. Interesting.

Easy way to check:

Take a pair of dial or digital calipers (cheap ones will do) and measure from the ID of the barrel to the OD od the threads at 4 clock points (12, 6, 3, and 9). Make sure you note if you are on the rifling landings for each measurement.

If the mesurements are equal you're GTG.

Mot45acp said:

Easy way to check:

Take a pair of dial or digital calipers (cheap ones will do) and measure from the ID of the barrel to the OD od the threads at 4 clock points (12, 6, 3, and 9). Make sure you note if you are on the rifling landings for each measurement.

If the mesurements are equal you're GTG.

Click to expand...

very good answer

Yeah I would definitely do that at the very least... especially if it is a bigger caliber taking a more expensive suppressor. Heck make that any suppressor in my book lol.

I had my local machine shop build 2 alignment rods which will just barely slip into my 223 and 308 barrels. They are long enough the stick out the end of my YHM suppressor and still enter my barrel at least 3 inches. The rods started out a bit larger than the bore dimension of my barrels and the shop turned down one end of the rods to fit in my barrels. So there is a "step" that stops the rod from entering the barrel more than 3".
I install an adapter on my barrels, screw on the suppressor, then insert the check rod. If it is centered in the exit hole of the suppressor it's good to go.

BUT, the simple 4-point measurement given above should be sufficient. If you can look through the bore from the breech end with suppressor installed, you should not be able to see the suppressor at all- just a round hole.

For what it's worth-I have not had to do any modifications to any of my factory-threaded AR barrels. A total of 7 so far and some of these came from Blackthorne......

edit-MY YHM QD suppressor is 308, but I use it on several 223's as well.

Here's a nice write up on barrel threads done by Adco Firearms. LINK HERE.