View Full Version : 9mm to 40? WITH A BARREL CHANGE?

January 7, 2011, 10:19 PM
] I saw today in another forum a report on changing a S&W M&P from a forty to a 9MM by changing barrels and mags???? Said it worked great and will save money on ammo.

Can an XD 9 change into a 40 w/barrel and mag conversion? Seem to be same platform?

January 7, 2011, 10:38 PM
same platform but breach face of the slide cut for 9mm will NEVER fit a 40 S&W case....sorry !

It's too big !!!!!!!!!!!

January 7, 2011, 10:50 PM
Sooo!. You can use a smaller ammo taking a 40 to a 9 but can't go up from a 9 to a forty. Right???

January 8, 2011, 12:53 AM
In most cases you can't go up from a 9mm. Most common swap is from .40 to .357 sig.

January 8, 2011, 02:59 AM
Some have made the change but leave out the word 'reliable' !! :rolleyes:
Bore , chamber, extractor, ejector and magazine all are different .

January 8, 2011, 03:03 AM
40>9 but not 9>40, correct.

January 9, 2011, 08:31 AM
.357 = .40 case necked to 9mm

9mm slug and .40 rim. With a .357 Sig chambered barrel you can reliably change from a .40 S&W to a more expensive .357 SIG. With the 9mm barrel as others have said the rim on the casing is smaller and the extractor will have some issues snagging that rim. (you might need a lighter spring, too)

January 10, 2011, 09:01 AM
There was an attempt to make this work years ago before the 40 s&w. I think it was called 40 AE using a case similar to the 40 s&w with a rebated 9mm rim. I've seen Browning HP types with both barrels/mags. A great idea that came before it's time. My recollection on this is a little fuzzy.

January 10, 2011, 05:11 PM
I think it was called 40 AE

.41-AE. :)