Re: wolf conv. barrels for glock 31
I have a G20 that gets a 40SW conversion barrel so I can shoot both calibers. I don't change mags, I just swap the barrels and shoot them.
The LWD barrels also have a fully supported chamber (at least my 40SW does) so you don't get the dreaded "Glock Smiles" in your brass, you can load hotter rounds with it and not worry.
With the 40 barrel I can push a compressed 40 load faster than a 10mm load because of the brass being supported.
For a 9mm, you shouldn't have any issues whatsoever. The other nice thing is you can put some super hot 9mm loads in it, load them long because the action is there to take the extra length, and shoot them without an issue. The heavier recoil spring will help mitigate the normal recoil problems.
Clearly this isn't a starting practice, you should work up to it, but it's possible.