Quote Originally Posted by NeiljohnUK View Post
I always wonder why with rifle barrels they don't recess the crown, with my PH bull barrelled target rifle it was the best way to protect the crown, would that help the situation with threading I wonder?
Since I am not a gunsmith never claimed to be one and have not played one on TV, I cannot give a qualified answer to that question. I can state from my own experiences that even a small nick on the rifling will affect the predictability of a bullet's trajectory. When I bought My .270 the end of the barrel liked like someone had driven a tapered pike in it the riflings were flattened about .050", I made a brass guiding tip for an internal chamfering cutter then carefully cut a chamfer in the end of the barrel afterwards with the aid of a 4-inch magnifying glass I used a very fine jeweler's file to remove any burs on the rifling. Now it will strike kitchen matches at 300 yards. So, there may be a plausibility to your question since the crown might be damaged during the machining process if the smith was not attenuative if he used a centering arbor for a threading die holder.