Helping out a friend, we were breaking in a full size stainless 9mm Springfield 1911, bushing type barrel, target sights, full length guide rod.

Before the range, I disassembled, cleaned, and lubed the gun (wet) with CLP.  This gun was tight, frame to slide, barrel to slide, etc., tight as my GSR that I used to have.

We were shooting 115gr PMC rounds.  This gun was a jam-o-matic, with stove pipes, fail to feed, nose dives, etc. The slide would often not lock back after the last round.

After around 100-150 rounds, it didn't get any better.  I cleaned it at home, and re-lubed.  The slide, when you pull it back manually and try to slingshot it forward, would hang on the corner of the hammer sometimes, and not return to battery.  If you just eased the slide forward, it would hang up every time.  I verified it was the hammer by putting a screwdriver through the hole and taking pressure off the hammer, the slide went to battery.  I manually cycled the slide over and over trying to break it in.  The oil at the slide gap was noticeably black, as the surfaces were obviously lapping each other and removing some metal.

This one may need a trip back to the factory.  I was tempted to put some compound on the rails and polish the hammer surface where it rides along the slide, but I don't want to screw up the warranty of a gun someone else owns.

Sounds like an extractor issue. Make sure it's properly tensioned and try new mags. It also sounds like the slide is traveling faster than the magazine can keep up.

Polishing the slide/hammer is not really a thing.

To me it actually seems like the recoil spring is overpowered.  The extractor didn't draw me to it, but will look at it the next time I am around it.

I gave him some HST ammo, which I think will improve things.  Most of the symptoms seemed like the ammo was under powered.

I have no other experience with the PMC 9mm, and I wish I had taken a couple boxes of my full powered reloads with me.  It was a .38spl day for me, so I had nothing else in my range box.

I did recommend the CMC Power mags and at least I could make sure they fit his gun before he went home.  I would have taken them to the range if I had known we would have issues.

I can't say enough how tight this gun was, tighter than I have seen for quite a while.

People goof on Kimbers, but mine have run 100% out of the box.

I have the RO  in 9mm and while I did have some "new" FTF's they were very random and not of concern. My reliability after some break in has been outstanding. I can also comment that my RO has the smoothest functioning as far as precision slide to frame fit. I also polished the feed ramp, it's something I do on all my semi's . I also like to polish the inside of the feed lips on my mags. My RO feeds all the common 115 and 124 gr ammo.  My Kimber 10mm Target II long slide feels no where near the smooth slide action that my SA RO exibits. I've read nothing but positive CS from Springfield, so worst case scenario is it has to go back , but they will make it run right.

I had problem with my Loaded target in 9mm when first got it. Bought some Tripp magazines and it ran flawlessly after that.