Broken end of cartidge in barrell

I just finished shooting (2) 50 round mags through my PS90 today and had inserted my 30 rnd mag. The next shot fired but when it did the bullet end of the cartridge blew off into the barrel. The next round slammed into the broken part defoming it substantially. I must be a little slow because I tried two more rounds with same results. I'm used to the AR's and sometimes you just need to hit them harder. I am using brand new factory rounds, SS197SR in the white and Blue box. I am going to have to find out how to extract the case and try to find out why this happened. Any other experience with this out there?
My wifes purse was stolen today, the gun jammed up, and the garden pitchfork broke. That should be my trouble in three's, time to move on.