I am new to this site and my question may have already been answered, but I can't find it. My SD40 does not like PMC 180gr ammo. It will load and fire absolutely wonderfully, then the slide will not go completely forward and seat the round. A sharp tap on the rear of the slide usually feeds the round. New gun, only about 200 rounds thru it. Yes, it was thoroughly cleaned and lightly oiled before first range time. It will feed 165gr HP just fine, not a single FTF. My stupid question is: would polishing the inside of the slide rails with something like Flitz polishing crème be a sensible solution?
I have a new SD40 and when I was cleaning it before the first range trip, I noticed the feed ramp on the bottom had a bit of a lip. Almost like a milling or finishing mistake. I took a very fine file and slowly worked the lip off of it. It took about 40 minutes of painstaking work, but it is smooth now. I felt the rest of the ramp was plenty smooth so I left it alone. Mine has shot Remington UMC 180 grain with no issues
Doin' what I can, with what I got.
Any light weight framed auto pistol can suffer from "limp wrist" related malfunctions. You noted the 165's work fine, but the 180's are problematic. The recoil impulse of the 180 is slower and you may be allowing the frame to move too much in recoil causing it to short stroke enough to cause this problem.
Most folks relate limp wrist to stove pipe ejection problems. Lesser degrees of limp wristing can cause feeding/locking problems.
Hold on tight and slow fire a few rounds. Does the problem persist? It could be the ammo made at the PMC factory called "Pretty Much Cheap"
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