New PMR 30 issues

Bought a new PMR30 at the beginning of November. Over the next month I fired 600 rounds of ammo through the gun, a mixture of CCI, Federal and Winchester 40 grain ammo. The gun functioned great. I disassembled and cleaned the gun every 200 rounds. Then out of the blue I started having issues with the gun. I started to have 2 to 3 failure to extract or failure to eject stoppages per magazine. When I had the failure to extract stoppage the fired case was stuck in the chamber, the slide had cycled and the subsequent round from the magazine tried to feed. To clear the stoppage I had to drop the magazine, lock the slide to the rear to allow the live round to drop free and then use a range rod to push the fired case out of the chamber. When I had the failure to eject stoppage I would find the fired case stuck between the breech face and the barrel hood and the next round from the magazine partially fed. To clear it I would pull the slide to the rear and the fired case would drop free and when I released the slide the next roound fed. I took the gun home, disassembled it and cleaned it using an Otis Ripcord for the barrel. I lubed it and took it to the range again. I still had the same issues. I returned home and contacted Keltec online and initiated a service ticket. Then I disassembled the gun again and took a close look at the barrel. I didn't notice anything unusual, but I decided to use a bore brush to clean the barrel and chamber rather than the ripcord I previously used. I also use a .243 nylon bore brush to scrub the chamber. After I cleaned it I took the gun back to the range and lo and behold it shot great, until I reached the 85th round.

When I pulled the trigger the gun fired, but I also received a face full of powder and metal shavings (thank God for eye protection). When I examined the gun I found the slide pushed back, a round attempting to feed from the magazine into the chamber, but the chamber contained a ruptured case from the CCI ammo I was using. It appeared the case ruptured at the rim out the top of the case. I am not able to lock the slide to the rear. I am able to see down the barrel and it is not bulged. I have not attempted to disassemble the gun. I updated my service ticket with Keltec and also called their customer service to request a return shipping ticket. Unfortunately they are going on Christmas and New Years vacation and told me to call back in January. I will wait and see. At this point I have fired just under 900 rounds through the gun.