S&W M&P Fail upon mandatory chambered reload. Fix?

[garybusey]

the .40 mag feed lips are a bit too wide for the 9mm and are not reliable enough.

hmmm, instead of cutting the followers or cutting the springs why not try running 40cal mags in it?
i know they fit in the 9mm fine.
i also know they hold 12 9 mm rounds.
so if you loaded them with 10 there would be a a lot of room still in them, thus them not being so tight when you try to slap a full 10rd mag in.

i dont shoot comp but i do have a M&P 22, 9, 9 CORE, 40 and 45 and i noticed that the 40cal mags fight in the 9mm.

might save you doing alterations.
im kinda interested in this problem.
i have a brand new 9mm Pro CORE and i think ill to test this at the range next week to see if i can duplicate your problem.

 

[Canuck44]

hmmm, instead of cutting the followers or cutting the springs why not try running 40cal mags in it?
i know they fit in the 9mm fine.
i also know they hold 12 9 mm rounds.
so if you loaded them with 10 there would be a a lot of room still in them, thus them not being so tight when you try to slap a full 10rd mag in.

i dont shoot comp but i do have a M&P 22, 9, 9 CORE, 40 and 45 and i noticed that the 40cal mags fight in the 9mm.

might save you doing alterations.
im kinda interested in this problem.
i have a brand new 9mm Pro CORE and i think ill to test this at the range next week to see if i can duplicate your problem.

They should the 9MM. 40cal and .357Sig all use the same frame and inards. The slide and barrel are the only difference and that because the slides are engraved with the original barrel/caliber combo.

Take Care

Bob

 

[enefgee]

I doubt it's the mags, unless the force required to seat the mags is enough to cause the 'dead' trigger as mentioned earlier. FWIW I've just rebuilt all 6 of my mags with new springs and followers, have the old style block and am a ham fisted reloader and it hasn't caused me any issues. As far as recoil springs go, I've got 30K on the one in my gun now with no issues. Out of battery - I can go down to .17 splits and not have a misfire, and I only use CCI primers, so doubtfull there too, unless you're under .15 (I've done .15 on a couple of occaissions with no issues). I guess the key question is do you have the small sear spring or the larger one - and does the pistol have anything done to it (Apex forward set trigger can cause dead trigger if used with the small sear spring block). Dead trigger in the Pro is a known issue - check out the M&P forum.

 

[Messy Pants]

have you modifed your followers yet?

No I will be doing this for two mags tonight and range testing them. I am convinced now it is more likely the mags. It almost takes a hammer to seat the newer mags. I am going to shave a little off and test it.

If I eject a half empty mag and jam in a full one that is where the problem occurs almost every time.

 

[KevinB]

Never heard, or seen of that issue -- I have seen dead triggers on older guns, but never this. My M&P45T (threaded barrel) had the dead trigger earlier on - I ended up stripping it completely (I mean completely) and scrubbing the crap out of it, and that seemed to solve it.

The .45 10rd and 14rd mags and the Shields 7 and 8rd mags are fairly stiff to reload on a closed slide - but not impossible.

I don't have 10rd 9mm mags so no idea on your issue or if that can be an issue -- it does seem strange though.