Sorry to dig up my old thread but I thought I'd post back.

It took two trips to S&W and about 2000rds over the last year and a half to get this sorted out.

I tried a lot of oils and good old 3 in 1 seems to work best in this gun. Put another 300 rounds in it Tuesday night and only had two minor feed issues at the last round. No jamming and no stove pipes.

I only saw some light machining on each trip to S&W so in retrospect I should have just shot the **** out of it and perhaps lubed it with some sand and oil. Kidding on the latter..