IMHO, which may not be worth much, I think for the higher price of .40 ammo vs 9mm, with no more gian than you really get... stick with the 9mm.
If you want bigger, step up to the .45ACP, or even 10mm if you are really in love with a .40 cal bullet.
If you want bigger, step up to the .45ACP, or even 10mm if you are really in love with a .40 cal bullet.