Thanks!
Thanks for the better diagram and the great description of what the hammer lock may be and how it may operate. I've owned my Winchester Model 100 308 since it was new, in 1969, and hunted deer with it ever since. My dad gave it to me when I was 11 years old. It recently had it's first failure. It went "full auto" and emptied itself. After inspection, a couple of single shots, and then working correctly in semi-auto, it then fired while closing the bolt while loading, with the safety on. I took the gun completely apart and cleaned everything. The 3-piece bolt assembly was dirty inside, with metal shavings present, and it worked rough. After cleaning, it worked smooth. The hammer lock operation wasn't clear to me. These answers will help me inspect this. Since cleaning, it has worked fine for about 20 rounds. The gun has the safety recall firing pin installed. It will be going to a gun smith for a check before it gets used again. Can a dirty rotary bolt assembly cause problems like this?
Bill