Originally Posted by MrWray
Show him the difference between a .357sig bullet "which the G31 takes" and a .357mag bullet. Then let him explain how it is possible to shoot a .38 out of it.
I'll be pretty impressed if he can simply load a mag.
OP- If your friend wants cheaper range work, he can add a 40sw barrel or (40-9) 9mm barrel for about $120. Both are a lot more affordable than 357sig. The 40sw will run fine with his stock mags, and the 9mm probably will as well.