Birchwood-Casey Choke Tube Lube. Protects to 2000 deg F.

Been using that the past year and it's about the best thing I have used in over 35 years. Regardless of what powder (Black Mag'3, 777 2FG&3FG, Swiss & Goex Black Power).

The most important things are:
1) Use anti-seize lube of some sortliberally every time.
2)Do not reef breech plugs and nipples tight. Just snug them up.
3) Every 10 shots or so, slightly loosen and re-snug them.
4) Detail clean and the end of each shooting day. Even if you have only fired once. Ioften remove the breech plug or nipple immediately when finished shooting at the range if it's accessible.

Good Luck!