I just purchased a new mag for my S&W M&P 9mm. Got it from a reputable dealer. When I got it the bill said it was a 9mm mag but the writing on the mag itself said it was for a 40/357 S&W. When I called the dealer he said that was OKAY. I can actually load 12 9mm rounds in it. Not complaining just want to know if it's legal!
S&W M&P Mags for 9mm and 40 interchangeable?
- Thread starter Rob Beauchamp
- Start date
Ryan112929
Member
- Location
- Saskatchewan
I know a guy who'd buy the .40 mag from you if it doesn't work out and you have trouble returning it...
The dealer is full of BS. 40 Cal might work in the mag but it is more likely won't. None of my 40cal M&P mags would reliably feed and often would, with a tap on the bottom of the mag, unload the rounds on to the floor. You paid for a 9MM mag and you should have got one. Just saying. You are not going to be happy.
Incidentally my Beretta 92A1 loads 14 9MM rds in 40 cal mags but unlike the M&P mags, the Beretta mags are identical in every respect and do work.
Take Care
Bob
Incidentally my Beretta 92A1 loads 14 9MM rds in 40 cal mags but unlike the M&P mags, the Beretta mags are identical in every respect and do work.
Take Care
Bob
No it wont work. The lips are too far apart, and they are hardened and won't bend.
You can cut a relief cut at the base and then soften the lips with a torch and then bend them in a bit to fit a 9mm - but that would not be legal.
You can cut a relief cut at the base and then soften the lips with a torch and then bend them in a bit to fit a 9mm - but that would not be legal.
I can confirm.
Bought a 9mm Storm Lake barrel for my 40. Nope to the 9mm fit and feed in a 40 S&W mag.
- Location
- Blaster land, Okanagan BC
It works with the one .40s&w mag I have, but...
Because the follower sits at a higher angle, on the second last round the slide locks back. So you have to drop the slide manually to chamber the 12th round. I find some ftf when rapid firing or doing fast double taps, if shooting at a steady pace and rhythm mine feeds fine.
So being unable to legally modify the follower or bend the feed lips in more it's not worth it to shoot an extra two rounds if I have to manually drop the slide to chamber the last round, it works but it's not worth it. I'd rather drop the mag and reload, it's likely just as fast if I do my part.
Because the follower sits at a higher angle, on the second last round the slide locks back. So you have to drop the slide manually to chamber the 12th round. I find some ftf when rapid firing or doing fast double taps, if shooting at a steady pace and rhythm mine feeds fine.
So being unable to legally modify the follower or bend the feed lips in more it's not worth it to shoot an extra two rounds if I have to manually drop the slide to chamber the last round, it works but it's not worth it. I'd rather drop the mag and reload, it's likely just as fast if I do my part.
- Location
- Blaster land, Okanagan BC
Comparison pics between 9mm and .40 on page 2
https://www.canadiangunnutz.com/for...-9mm-mags-for-MP40?highlight=M&P+9mm+mags
https://www.canadiangunnutz.com/for...-9mm-mags-for-MP40?highlight=M&P+9mm+mags
I have MP40 range kit, and bought storm lake 9mm conversion barrel. NO PROBLEM using my five 40 mags for 9mm for the past 3 years. 13 rounds 9mm in them, but I won't bet my life on them. given all the reports and people here, I think I may just be lucky.
