Quote Originally Posted by bczrx View Post
Tang or lever safety? I have no knowledge of newer 99 rifles, as both of mine are from the '50s. If this were happening on mine, I'd also check hammer/sear faces to be sure someone didn't botch the surfaces. Probably not possible to cause your probs that way, but I wondered if the wrong contour on hammer., could make it not slide up sear properly to the 'normal' spot it rests. But, after firing, these two surfaces are not in contact, so the sear is no longer preventing upward hammer motion. And, sine the hammer is in the bolt, the bolt 'pops' up into full battery position.

More knowledgeable people will chime in and confirm my idea or destroy it. I am no expert: just thinking.

I don't know if this translates to tang safety designs or million plus rifles. I am basing my ideas on a sample of 2 99s from 1954 and 1957.

Good luck!

A 99 with a hammer? That's a rare bird !