Just took my Kel-Tec Sub2000 down for its first cleaning. Followed instructions to the letter. Now I can't get the bolt assembly to go in far enough. It will go just far enough to let the bolt handle line up with the end of the slot, not even with the hold back notch even. It was cocked and on safe when I removed the buffer to slide out the recoil spring and bolt which came out easily. Now I can't get it back together. Any suggestions as to what the problem may be?