One very big oops. I fired a round in my Polytech M-14s that hadn't been taper crimped. The bullet lodged in the barrel and Idiot Moron Trigger Puller failed to notice that little teeny fact. The loads I was using were running around 2900 fps and the next bullet blew out the side of the barrel. No idiots were harmed. How much taper crimp is enough for a semi-auto .308?