I picked up a new M&P .40 pro recently, and like others, i cant find any mags for it. This gun is for USPSA limited division. I have enough 17rd mags that i am thinking about trying to modify one to work with the .40. Has anyone tried this? Ive already order a couple .40 followers, the mags measure almost exactly the same except the feed lips, they would need opening up a little. Would like to hear any first hand encounters on this.
Anything is possible, but the width of the 9mm mag should be too narrow for the 40 cartridge to fit in. Even if you could get them in, you would have feeding issues. If you try to bulge the mag wider, then it won't fit into the mag well. Keep looking and get the correct mag for your gun.
You might give them a try just as they are. I've had a few that work without any changes, just for range work. I wouldn't mess with the feed lips myself if it doesn't work as is.
Last edited by handgunner356; 02-07-2013 at 02:08 PM.
I know were talking about different guns here but I had a Beretta 96 in 40 and a 92F in 9mm. The mags from one worked good in the other. Never had any feeding problems in either caliber using either mag.
Give them a try the way they are. You might get lucky and they work.