stress releiving is a process that removes, how can io put this, tight spots in the steel, some manufactorurs use heat then let the barrel cool down naturaly others use a process called cryrogenics you've all heard of it, working at the ends of the barrel does not cause stress, threading is a perfect example, anything else does. as far as harmonics, every time the bullet goes down the barrel the barrel sings a song, if the song is the same tone every time or as close as possible you have an accurate barrel, if its not the bullet will do some funky things and exit not spinning true to its axis, hence flyers. now on to lathes, if you check out what kind of lathes are being used in this area you'll find most to be chinese or korean, belt driven junk!!!!!!!!!
how can you produce proper results if the machine isnt capable of precision.
just alittle food for thought, my lathe is manufactured in germany and is a single production precision lathe. thought you guys would like to know. mike