Folks I had a scare today at the range. I had my Black Shadow 30-06 ready to test some loads. I cycled a round into the chamber and set the safety. I set the rifle into the sandbags and got into position. When I flipped the safety off, the gun went BANG . This is a "new to me" rifle, but I have shot it a few times. The previous owner said he only shot a 1/2 box thru it. The trigger is set on 3-1/4 lbs and seems OK. When I got home I dissassembled the bolt and cleaned it real good. After reassembly, I cycled the action 30-40 times operating the safety and the trigger. Everything seems OK.
What would cause such a scary thing to happen? The only thing I can think of is that the trigger-stop screw is set too far out.

Definitely drives home the "always know where the barrel is pointing" habit.

I would have a gunsmith look at it.

Hello Duckbill,
As RMiller said, find you a competent gunsmith, not a hobbyist or part time gunsmith, and have them check out and adjust/repair, etc. the trigger for you. Subject trigger is a good one and rarely gives problems unless someone has tampered with it and did not realize just exactly what they were doing or understand the mechanism of the trigger. Safety is paramount whenever a firearm is involved. Good Luck and Safe Shooting.

I know I should've taken it to a "smith", but you'd be hard pressed to find a good one in this area. Upon more thorough examination, I believe the previous owner attempted to reduce the trigger weight and inadvertently loosened the trigger stop screw. My guess is that there was barely enough back tension to engage the sear and after a few shots it backed out to an unsafe point.
When I first examined it after the slamfire, I just glanced at the trigger stop screw and noticed the GOOP was still on it. So I figured it was still where the factory set it. Not the case...it spun freely and in fact the nut was loose.
I set everything back to what felt like a solid engagement and set the trigger to an even 3 lbs. I took it out this afternoon and it performed just fine.