The bolt on my Sub (par) 2000 continues to lock. On a recent outing I broke it out and loaded it with 30rds in a GLOCK factory 33rd mag. 4 shots and the bolt locked open and could not be moved. Upon my return home I broke down and cleaned the barely used gun and fired a few rounds with out incident. There was a loaded mag in, I removed the mag and cleared the gun. I put an empty mag in and drew back the bolt and again it stayed in the locked open position. I would be grateful for any help any one could offer for this issue. I would prefer not to spend any more $$$ on this gun and my experience with "customer services" was less than satisfactory, to say the least. I am disappointed in the over all quality of this gun and I am more disappointed by this because I love the design of this firearm as I do many of the other Kel-Tec designs, ( PMR 30, KSG, RFB etc...). At this point I have no confidence and would not buy another Kel-Tec. I know most people on this forum are fans of Kel-Tec and have not gone into any senseless bashing of the company, I just want to solve my problem. I would love some help in solving this issue, I have gone to the expense and time threading the barrel, so I would be happy for this to be a reliable firearm.