I purchased a new Kel-Tec Sub 2000 9mm Beretta 92 this November at a Dealer/Range. The dealer checked and lubricated the carbine for me. On the range the Sub2K 9mm failed to eject spent shells 4 times in the 1st 50 rounds fired. The spent casings would get caught in the ejection port by the bolt head and prevented the next round from loading. I was using Federal American Eagle 9mm 115 gr. FMJ in the 10 round Mec-Gar clip (MG-B92-9MM) that came with it from Kel-Tec.
I emailed Kel-Tec about the problem and they responded promptly offering to send me a ejection port clip to help resolve the problem.
I cleaned and lubricated the sub and fired another 100 rounds of the same ammo using the Mec-Gar mag. and also a Beretta factory 10 round mag. (PB CAL.9 PARA MADE IN ITALY). The PB magazine had a much stronger spring making loading 10 rounds difficult. I had 2 failures to eject with the MecGar clip and 10 with the PB clip. With the PB clip on 3 occasions the spent shell case stayed in the breech jamming with a new cartridge being loaded by the bolt and denting the next round being loaded. I cleaned and inspected the sub.
I received 2 metal ejection port clips within a couple of days from Kel-Tec and installed one. Installing the clip is simple and takes seconds to do. I went back to the range this time with Winchester 9mm 115 gr. FMJ. I fired 40 rounds using both mags, no more ejection problems! But the metal ejection port clip broke on the breech side right about where the 90 degree bend with the short lip is. I installed the 2nd ejection port clip and fired 120 rounds using both mags no problems.
I hope this information is useful to anyone else experiencing ejection failures. The metal ejection port clip is an effective quick fix, but I question the long term durability of the clip. I feel confident now that the problem is with the right receiver (part # SR-210R) in the area of the ejection port. I have read online that new versions of the sub have a modified right receiver that resolves this problem permanently. I intend to contact Kel-Tec in regard to this matter.
In all other regards I like the Kel-Tec Sub2K very much. It's light, compact, very accurate, light recoil, easy to clean.