Got a question about this gun. It's description makes it sound like it should do more damage than a ordinary gun (Man killer, tremendous stopping power at close range, making every shot count). But when compared with a Bolter it's actually equal in DMG 8, they got the same CC value -1, the Bolter is more accurate in PB 2 vs 1 and both got the same mod on SR 0. They both do Ballistic damage and neither got any load outs/ special rules.
All in all the M-13 Bolter seem to be the better gun.
My guess is that the S&W is incorrect on the DMG, perhaps 9 instead of 8. Or it's lost a special rule or type of dmg along the way.
Edit: fixed some typos, and added some fluff form the weapon description