Case Head Exits Rifle

[Kirk]

Jim:

The only way for a RRB to do what you describe is for the block to retract (the sear can't engage because you finger is holding the trigger/sear to the rear), the breach to open, the case head to pop out, the breach to close (powered by inertia?) and the the block to fall back to the fired position (finger still holding trigger to rear). The only way to power this sequence is for the firing pin to transfer enough push from the primer/gun powder to the hammer face that it actuates the block.

Check the clearance between your firing pin & firing pin hole. The 7 mm RRBs had a samll dia. firing pin. The black powder RRBs had a firing pin about .1" dia. It may be possible that you have a BP block & firing pin or that you have a BP block & smokeless firing pin. A contributing factor may be a weak mainspring since that is what keeps the block closed. The BP rifles, when converted to smokless rounds could do this. The fix was to bush the firing pin hole & use the smaller dia. firing pins. Remington recognized this problem & that is why the smokeless actions had the small dia. firing pin.

I own a BP RRB & have never experienced this although I use smokless loads almost exclusively. But, it's a .45-70 & pressures are low anyway. I once barreled a 7 mm action in .257 Roberts but kept loads to the 36,000 CUP limit of factory ammo. Again, never had a problem. What pressure level are you loading?