I am a machinist and I thread barrels for myself and customers all the time. I would NEVER use a die to cut threads on a barrel. Now, if you want to chase some existing threads or straiten up a "ding" on some threads - sure, no problem. As far as matching threads to the suppressor, it's your barrel, but that's not what I would do. I do not want a barrel that *may* only fit one device correctly. You are counting on the threads of the suppressor being perfect - and they may very well be, but I wouldn't bet on it. Make sure the barrel is in the lathe correctly, indicated to the BORE, not the O.D. - and cut the threads to spec. I use a combination of a quality pitch mic and a flash hider for "functional check". If your numbers are in spec (major, pitch, minor) - and it passes functional check - your golden. Not dissing your gunsmith, just sharing how I have done MANY barrels that have made 100% of my customers happy.
