Hello, mechanic. Glad your not hurt! I have heard that these things can happen..powder and primers can and do explode when subjected to sharp jolts. Few years ago, at a well known bench-rest match, fellow had new rifle with old handloads, managed to get ctg. stuck in chamber. Removed bolt & tried to push it out with cleaning rod from muzzle. Wouldn't budge..so he wacked it with palm..still stuck..whacked it hard..& ctg. fired. Now the tradgedy was, his wife was standing behind line watching when case hit her in stomach, despite getting her to hospital in record time, she died on operating table. Case was recovered...& primer didn't show any signs of impact. Husband said blow from bullet almost knocked him off his feet, but he held on to rod. Could the sudden pressure from the rod jamming the bullet down into case, compressing powder set it off? This stuff needs more testing.