Jim - Nice write-up on cleaning and break-in. I am about to receive my first custom gun, a .338 wildcat with a 36" Lilja barrel. I want to treat it as royalty. I am an engineer with some training in metallurgy, and there is one question that I have never seen answered about break-in. I know one very successful mile shooter who does no break-in, and says he cleans his barrel "almost never." I know others who will clean after each group, if possible. So I am really perplexed.
The question: What does break-in actually do to the metal of the barrel? When you say that you fire the first round, then clean out all the copper, what has actually changed in the barrel to make the next round behave better? And each subquent shot & cleaning? Any metallurgist will say that sliding one little copper slug down a hard & polished steel barrel will not change anything. Copper is just too soft to move any steel around. If you tell me that the breakin pushes copper molecules into tiny pores in the steel of the bore, and those embedded molecules never come out, I can buy that. That would smooth over microscopic pores. If you tell me that it's not the copper, but rather the heat of the gases that somehow changes the surface metallurgy of the bore, and that cleaning out the copper after each round just allows the gases from follow-on shots to make better contact with the steel, I can buy that too. But I just have a lot of trouble believing that miniscule contact with soft copper that peals off a bullet will change the steel in any way. I really hope you or someone else interested in this aspect can explain it to me.
My Navy SEAL son-in-law said then never clean barrels. They don't carry cleaning stuff, and they don't want to change the way a gun shoots.
Thanks,
Walt
Lebanon, OH