conversion barrels?

[mt-mag]

I have an M&P 40 compact and I want to get a 9mm conversion barrel for it. I can buy an S&W barrel for about $70. Or a Storm Lake barrel for around $140-180. Why would I spend the extra money for the Storm Lake barrel. I'm not a competition shooter, I just want a reasonably accurate gun for range and also for carry.

Am I missing something here? Would the S&W barrel do what I want? Help me before I spend more than I need to spend.

MTMAG

 

[rcmodel]

Just a guess.
I believe the S&W 9mm barrel fits a 9mm slide.
The Storm lake 9mm conversion barrel fits a .40 S&W slide.

The O.D. of the .40 barrel is larger then the 9mm barrel.
And so is the hole in the slide.

rc