I have been reading with interest, although I have had to re-read some parts several times! That comment about John Barsness saying that a smooth barrel increases friction due to more bullet contact really intrigues me. It seems almost counter-intuitive to me. Does anybody know where I can find where he wrote that? Article/book? It would be interesting to see if any other gun loony agrees or disagrees with that theory. (At least I assume it is a theory??) May need to start a new thread on that!
From this
thread in 2015:
That's exactly what happens. Beyond a certain point, and even smoother finish results in more bullet contact with the bore, and hence more friction, resulting in more copper fouling. This is why some barrelmakers caution against using JB Compound very much in their lapped barrels. Eventually it creates an even smoother bore. Instead they like the bullet to be "riding" on top of the miniature striations created by a slightly coarser lapping grit.
JB usually doesn't affect unlapped barrels, however, because their surfaces aren't as smooth in the first place. But it can. My .338 Winchester has a take-off Sako barrel, which despite being pretty smooth tended to foul badly. Chemical cleaners took too long, so I started cleaning it with JB every time. That got rid of the fouling, but it started coming back even quicker. I was about to rebarrel the thing because it became caked with copper within 20 rounds, but then DBC came along and solved the problem.
