M&P 9mm failure to feed

[SKM&P9]

After cleaning polishing the feed ramp to a nice shine, with no visible scratches or burrs, I reassembled the gun and took it to the range. Loaded it up, racked, and bang,bang, and the 3rd rd. was nosediving into the feed ramp. But if I pull back on the slide just a fraction, the round pops up into the chamber like normal. I cleaned both mags, tried each with different ammo, ( UMC and WWB), and same result. Any ideas ?? The gun has a little over 1,000 rds.

 

[olyeller]

Did we get a little crazy with the polishing?, like enough to remove metal and change the feed angle?

How did it feed before the polishing?

 

[Car Knocker]

Why was it necessary to polish the feed ramp?

 

[SKM&P9]

I don't think I could remove enough material to change the feed angle using 600 and 1000 grit paper. I was told by the range operator to try polishing the ramp, maybe there was a burr or rough edge holding up the case.

 

[DWARREN123]

Possibll the mag is at fault. Just polishing the feed ramp should not cause a problem but changing angle or removing metal is a no-no.
I would check out the mag, follower and spring then the ears of the mag.
Also check the face of the receiver where it contacts the brass.

 

[rbernie]

My experience has been that most nose-dives are the result of the magazine not getting the round pushed up properly. If the spring is at fault, this usually happens on a specific magazine when the mag is full, and the frequency of occurrence decreases as the magazine empties. If the feed lips have a burr or are malformed, the problem is usually traceable to a given magazine but occurs randomly and cannot be correlated to how full the magazine is.