I'm having troubles with 9mm 147g ammo. It finally motivated me to stop lurking and join this forum.
ANYway, My I'm trying to load something quiet for my 9mm BRP. I test fire vertically into a bucket of sand in the basement. Not the safest perhaps, but it works for me.
147g/3.6g of TiteGroup ran away. Apparently not enough zip to send the bolt far enough to trip the sear. I bumped the load up to 3.8g, same problem. By this point, the ammo is pretty hot according to the specs I have.
It COULD be the fact that I'm firing the gun vertically, but I'd rather the angle not be a critical factor in reliability