I have a Volquartsen Predator in 17HMR , fairly rare. I was at the range today shooting Hornady 17 grain, I had ran twenty plus rounds of CCI 20 grain HP. I shot (17 grain) and the magazine blew out of the receiver in pieces. The projectile and brass case were left on the bench with the magazine pieces. Several guys shooting came over to see what happened. I am including pictures, check them out and see if you feel the same as one of them speculated. He felt that the bolt was pushing the round in the chamber and hit the rim enough it fired out of battery. It happened so fast I am not sure. I pulled the trigger and the round exploded.