Two friends are leaving tomorrow for Africa. Last week they were firing more rounds in preparation for the trip and both guns failed. Gun #1 was a factory Sako 375. It would not extract. It was determined that the headspacing was 18 thousandths over. The extractor was hitting the rim and not going over it due to the extra length the cartridge was forward. A burr had formed after numerous firing. A file solved the problem until the barrel can be turned back a scoche. The second gun was a customized Rem Mod 30 in 375 H&H. The problem was solved with a new magazine spring. Better now than next week with a Buff hunt.