I bought a 6 7/8" slabside used and was experiencing FTE and misfires, about 1 out of every 10 rounds. I disassembled the gun and discovered some wear on the face of the firing pin and the corner of the extractor. Normal since this gun is 15 years old. I purchased a Volquartsen firing pin and extractor and it's performed admirally ever since. Definitely makes the MKII ultra reliable.