Joe,
The TSXs (and all the other "banded" bullets from Barnes) don't have the same fouling problems as the original X's. I shoot them a lot with some gilding-metal fouling in rifle bores, due to shooting a bunch of different handloads in a single rifle for articles, and can't recall any problems.
Hornady and Nosler monolithics are made out of the same gilding metal as most rifle bullet jackets, instead of pure copper like Barnes, so there's normally no problem there either. (Gilding metal is a mild brass, mostly copper with a little zinc.)
