Thread: A conundrum

When we were working soft loads for the 7.62x39 we found that if we went over 1100fps (or about) we needed gas checks. at about 1200fps we found the lead was "melting" in the bore and after about 4 or 5 shots he had turned his rifle into a smooth bore by filling the rifling with lead. Once the lead was removed and gas checks fitted to cast loads it went well. I do not know if this is what is happening to you as you mention that you have no lead fouling, but it could be worth checking into...