When I first tried my reloads in my new M&P Pro 40 it was a disaster. I was using a 175 grain TC lead bullet that worked well in my XD. Not in this gun. First effort was probably 30% failing to feed. I polished the ramp but also put a slight taper crimp on the rounds. This resulted in about a 3% failure to feed. I seated the bullets a bit deeper with no improvement of the 3% failures to feed. I inspected some of the failures and noticed a slight dent on the edge of the TC so now felt they were jamming into the top.

I had some Ranier plated RNFP bullets loaded up some time ago so took 50 rounds to range to test those. They all had a slight taper crimp. All 50 fed with no problem and the slide action felt so smooth now. I hap always noticed a slight "catching" while loading the first round on those TC and now that was gone.

I'm going to try the TC bullets once more but this time increase the COAL. Worse comes to worse I can use those TC rounds for practice as the bullets cost me nothing and use the RNFP plated ones for matches. Anyone have any other ideas on this?

Are your bullets sized to 0.401"? If they are fatter, you will have to either size them down to 0.401" or seat them to where the cone touches the case rim, no higher.

Both 9 and 40 barrels in my M&P have narrow throats. Bullets must be sized to 0.356" and 0.401" and no wider or I see scrape marks on the shoulder of the lead if it goes into battery at all.

You can test this out by taking some calipers to measure the vertical part of the lead projectile. If it's bigger than 0.401", use a magic marker and color the whole cartridge, then try the plunk test to see if the cartridge fits cleanly into the barrel. Pull it back out and look for the wear marks. Sometimes it may be at the bottom of the case where it was not resized fully, but in your case it's probably on the bullet.

Good luck

Thanks for your thoughts. My bullets are sized to .401 and on the last test with the TC they were seated to the spot where the taper meets the straight wall of the bullet. I have read where some folks have installed a new extractor to fix this problem so maybe I'll consider that option too.