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Suppressors In Michigan, suppressors are becoming quite popular and I have received several requests for barrels cut to an over 16" length and then crowned and threaded. I have discovered Mark Bozek many garden variety (budget model) barrels demonstrate some bore "wandering" that is quite apparent more in the middle section while being rather concentric at each end. I have chosen to decline the work until I can definitively confirm parallel threading to the bore and not just to the exit hole or O. D.

If it were a muzzle brake, the matter would be of little concern. Since some suppressors are quite long, the accuracy of the alignment becomes more critical as the hot gasses of the propellant are pushing the base of the bullet past each baffle plate prior to exiting the suppressor. I would have to believe the more concentric we are the better. My sketches illustrate this further. As the drawings indicate (purposely exaggerated) the last few inches of the bore proper would determine the bullet path.

With a brake or other short attachment, the angle of the bore at the point of exit would be far less critical. A 6-8" suppressor would require the last baffle set and baffle exit to be in line with the last few inches of the wandering bore. Though not absolutely necessary to avoid baffle strike, uneven, off sided pressures on the bullet base as it clears each baffle would create, in my opinion, a much more dramatic shift in P. O. I. between unsuppressed and suppressed.

It would seem to me there would be some way to jig the barrel and turn the barrel so the bore is running dead nuts true regardless of the O. D. of the barrel or the angle created by the offset. This problem seems to present itself when the muzzle end is shortened to a legal BATFE length of greater than 16". It appears the bores run relatively true near their manufactured ends which would explain

why there is so little concern when purchasing a unit that has been threaded by the barrel manufacturer. It seems to raise its ugly head when barrels of unknown heritage are encountered and a cut, crown & thread are requested. If I could fixture the barrel in such away to ensure zero run out of the last few inches of the bore, I could be quite certain the suppressor would perform at it’s highest potential. David Dumeah David Allen Dumeah Gunsmithing From Norman Johnson.

If the hole in your barrel is not straight, application of a suppressor could present an accuracy problem. I have not seen a crooked bore in many years. It would seem to me if your barrel is concentric, as cut off, there should be no problem in getting a well-centered thread. Wouldn’t your lathe tail stock center your bore perfectly for uniform thread cutting? Perhaps the suppressor manufacturer can shed some light on this matter for you.

Scope Mounting for Accuracy First, thank you for providing outstanding information. I have enjoyed American Gunsmith for years. The article "Scope Mounting for Accuracy" (March 2020) was great! What I failed to identify or learn was which gun vise provides the best or easiest platform to achieve level and hold the firearm? Everything else was there and I follow many of these steps, plus I learned why I want to do things I may not be doing consistently.

Rick Fitzpatrick Prometeon Tyre Group Commercial Solutions, LLC Author David Manney responds. I use a soft jaw in my bench vise. I can rotate the gun and raise or lower the butt end to get it level. Then tighten it to hold while doing the rest of the work. I used a Tipton gun vise in the pictures to make it easier to take photos. The soft jaws are sold by Brownells.

Enhanced Buffer Tube Concerning AR-15 bolt carrier tilt, would an anti-tilt buffer tube such as the Enhanced Buffer Tube from Primary Weapons Systems (the kind that has lips supporting the BCG) mitigate tilt in a standard internal pistol AR-15, even though the anti-tilt buffer tubes were originally designed for use with external piston AR conversions? Dylan Paterson From Joe Carlos. I tried that buffer tube and it didn’t begin to provide near enough lift. It gave me zero improvement. AG