....after placing an M357 barrel in the S40 that is. I only fired 50 rounds of WWB .357 Sig ammo purchased from Wallyworld. Results? No malfunctions at all; very accurate round through the gun; but.....one round discharged but sounded a little different than the other discharged rounds. I later discovered why...well sort of...that round's primer was pierced. I could clearly see the anvil of the primer. Despite that, the gun handled the round with no problems. Anyone else try this combination out? Now to get some hotter ammo and see how the gun handles it.