Historically, my gun-bunnies always kept a nice-cheap sawn-off T-250 on-person specifically for weird ammo (shock-lock requirements, flare rounds, Dragons'breath in old versions etc)
Does SR4 have rules for Coin Shot? This could bring the Roomsweepers back into action

Myself, I've never dealt with it before, but having just seen resident Evil:Afterlife, and playing too much Fallout:New Vegas, I'm curious as to the mechanics of it.
A) It looks like the mass of a slug, but spread like Flechette.... Would it be just a higher Power Flechette Round?
B) Is it just the same as Teflon Flechette, where the AP penalties no longer apply?.. or would they be worse as coins more likely to bounce of hard armour?
C) Secret option C)