M&P Full Size 40 Conversion to 9mm

[Whit]

A friend has an opportunity to get a M&P FS 40. It is possible to convert it to 9mm by replacing the barrel, recoil spring and mags? It would be a range pistol. Thanks in advance.

 

[scattershot]

I’ve done it. A barrel and magazine are all you need. Easy peasy.

 

[WR Moore]

Just be careful you're dealing with the same mod (1.0 or 2.0) version parts.

 

[1sailor]

Never done it with a 2.0 but did with my 1.0. You don't even really need new mags they just will tend to lock the slide back when there's still one round in the mag. I put a few thousand rounds through it in both calibers with no problems other than the slide lock.

 

[Oldsalt66]

From .40 S&W to 9mm it's just a barrel and magazine swap.

The recoil spring/guide rod assembly remains the same.

From 9mm to .40; it's a no go.