My shooting friends and I have loaded and fired many tens of thousands of rounds of .30 M1 Carbine using H110, WW 296, and Hercules 2400 powder behind 120 grain RNGC Lee bullets and various Lyman RNGC bullets up to about 125 grains. No leading problems and no functioning problems either. If you don't use gas checked (GC) bullets the gas port may tend to clog up with extensive shooting and cause short recoil malfunctions. No problem. Just get a gas piston removal tool and clean the port using a hand-tuned drill bit that fits the port.

Using 110 grain RN jacketed and Hornady 100 grain half jacketed bullets, we have had no problems at all.