Hope everything turns out....
ToddG said:So someone modified your pistol ("great trigger job") and now it's not working. Did it have any of these problems before the "great trigger job" by chance? Did this "great trigger job" happen to involve polishing the feed ramp or any work to the chamber?
When you replaced the mag catch, did you use a factory standard part? There are folks on this forum who recommend doing a little "work" removing material from the catch. Done improperly, this could easily result in a magazine that isn't being held in place properly therefore resulting in misfeeds.
ToddG said:So your gun ran fine for 3,000 rounds and suddenly it's having a problem feeding?
More basic questions, nothing against you personally just a standard approach:
1. Have you been cleaning and lubricating the gun the same way as always? Same solvent, same lube, same method, etc.
2. Is it happening with all ammunition or just one particular load? If just one, have you shot that ammo successfully in the past?
3. Is it happening with all your mags or just one mag?
4. You said you replaced the mag catch. Did the problem only begin after you put the new mag catch in?
In my experience, guns don't spontaneously start having feeding problems like this. If the gun was new, maybe there could be a defect. If the gun was nearing the end of its service life, maybe something has worn out. But at 3,400 rounds you'd expect the gun to be just fine. So unless something has changed recently (like the mag catch) it's an awfully odd problem.
FieroCDSP said:This might help a bit. I have been loading 155gr Rainier flat points (they're cheap) since late last year. During my load work-ups, I found that my flat-point loads over 1.130" OAL were prone to jamming against the top of the chamberI reduced them to 1.125" and all traces of it stopped. I load a meduim load of CLays, so my energy levels aren't real high, but I have reliable cycle as long as the OAL is below 1.130". Usually, all it takes is a slight pull back on the slide for the round to free up and go about it's business of being potential energy. I think it's your bullets. I've shot 165gr WWB with no issues, but that ammo has had QC issues before. IF those rounds were slightly long, they might jam like that, simply because the 165's are a tapered down 180gr, very similar to the Berrys.
The kicker is the Mag fix. All of the M&P's have somewhat loose tolerances at the mag-well. Mine usualy has a little bit that I can force it up further into the well. When you jam up in the chamber like that, and you push the mag in further, you're reducing the angle of the bullet to the chamber, and it frees up.
Try a lower charge and shorter OAL with the berrys, or a different profile bullet. I'd put 10 on that being the problem. If you're convinced it's an actual wear problem with the gun, a RN 165, shouldn't work.