[fiveman]

M40 A1: What can it do, what can go with it ?

What I do know is that:
Current M40 can be converted to 357 sig with a barrel change
M40 and M357 mags are interchangable if not the same
IGB and Steyr sell conversion barrels
There are stocks available but no 16" barrels
BT and and an Israeli company offer recoil solutions
BT sells other cool stuff
There are 10 and 12 mags availalble
What else ?...

This is the section that should be nesrly empty:
What I don't know is:
What calibre barrels drop in to the M40 frame without mods
What converts caibre without cutting ?
Can I convert to 9x18 or 9x19 or .22 rimfire at all ?
What aftermarket mags work with M40 ?
Which mags work with mods ?
What Mods ?
Does anybody do mods ?

Tell us what we don't know please.

 

[ETH77]

The .357 SIG barrel and the .40 barrel are identical except for the caliber and they use the same mag (since the .357 SIG is just a necked down .40). The 9mm barrels are not, and you need a new slide so you might as well buy a used 9mm weapon for the $$.

As far as mags, size wise the M&P mags are the same as are the S&W Sigma mags. The mag release notches are not, and there is the problem. I have successfully hacked M&P and Sigma mags to work in a M40-A1, however other members were unable to get my mags to work in their weapons, so obviously YMMV! I do so love having a 19 round .40!

As for doing mods, I don't know who does. Like I said, I just hacked mine, they are definitely not precision, but they work in my weapons. This is a real DIY project. Start with the notch too low on the mag and sneak up on it. You'll need a Dremel tool, or the HF equivalent. Get diamond bits, don't bother with the frangible crap that comes with the tools.