I have a couple rifle barrels I want to thread.  On one of them, I notice that the muzzle devices I'm considering attaching both slip over the unthreaded barrel and spin freely.  It seems to me, that if I'm removing material for the threads that the barrel should be a little bigger than the opening of the flash supressor, right?

So, what say ye?  Need a larger diameter barrel?  Smaller muzzle device?  I'm stupid and over thinking this?

NEED TO CHANGE SOMETHING.

larger barrel or smaller muzzel device.

Figgered as much.  Pretty sure it's an old AWB rifle and the threads were milled off.