Here's a good one. I have a browning A-bolt in a 338 win mag. I noticed something strange on the bench one day trying to work up a load for it. I noticed some trigger drag in the factory trigger so I was dry firing to find the Break point. I noticed when the trigger broke, that the reticle in the scope moved?? I checked the mounts and base to make sure they where tight and they are. The scope is on another gun and shoots great on that gun with no movement on dry fire. I put the damned gun in a vice to see if it was something I was doing. The jump at trigger break was still present even in the vice! Again I'm 100% positive it has nothing to do with the scope or mounts. It jumps about 3/4 inch at 100yds. Possibly the firing pin or spring? What could be causing this movement in the gun?