I wanted this until I seen it has issues with the factory mags
Sorry, this is a long post, and I don't want to hijack this thread.
However, if you're referencing the M&P 2.0 10mm, I got the 4" version back in 2022. I also picked up the 5.6" PC slide and barrel last year. I've put about 6,000 rounds, from the weakest (Federal) to the heaviest (Underwood, BB) loads with all sorts of factory ammo in between. I've recorded all of the failure to feeds, and these failure to feed problems were from several different ammo manufacturers.
Underwood SKU247
Blazer Brass FMJ
PPU FMJ
S&B FMJ
Double Tap (230 grain HC), though this could be from the larger grain bullet
Magtech FMJ
I'm a little OCD on this one, but I wanted to see what caused the FTF's everyone reported. Originally S&W was taking them back and polishing the feed ramp, but many reported it made no difference. I never sent mine to S&W and I never polished the feed ramp myself. Others recommended increased guide rod strength and magazine springs.
Along the way, I have added the following parts.
Galloway Precision 22lb and 24lb guide rod assembly
Springer Precision extra power mag springs (both version 1 and the latest version)
Apex Failure Resistant Extractor
New magazines (with the Springer Precision 140mm ext and extra power springs)
By far, the biggest difference was the Apex FRE, with only one FTF over the last 2500 rounds. I did change to the 24lb guide rod at this time too, though I tested the 22lb for a little while with the same good results. Prior to these changes, I had about 10-15 FTF's in the first 3500 rounds. Maybe that's not alot, but certainly more than I would like.
All of this info above just to get to what I found recently. In September of last year, I started getting the slide locking back when rounds were still in the magazine. It only happened on the 3 original magazines, with ~1500 rounds having gone through each one. One was worse than the other two, but the magazines with the Springer ext mags never had this issue, and I know I wasn't riding the slide lock on the original mags. I thought maybe the worn followers were causing an issue, and since AB1263 was coming, I contacted S&W to order some spare followers. I was lucky enough to get some spares before they stopped shipping to CA. When I replaced the followers on the original mags, the slide locking back problem went away completely, and it hasn't happened since in several hundred rounds. What I did notice is that the follower design has changed a little since the original magazine release. Maybe the FTF issue this whole time is the follower design?
Apologies for a going on, but I wanted to dump this info before I get too lazy to share it. It would be interesting to see if all of the recent M&P 10mm's have the new follower design or whether S&W ever shared their design change. I'm at the office, but I can add pictures of the followers later.
Oh, sorry, I never introduced myself to the forum. Tim here.