thanks for the info. i was hoping for something besides the sa mount. it looks nice but is too much. i went ahead and ordered the streamlight mount.
i would caution against using a scorpion or anything else not designed as a weapon light. a shotgun has quite a bit of recoil and the batteries will slam into the lamp assembly. don't think it'll hold up for long. on a .223 it would suffice but not a 12ga.
check out the tac star 2000, it's around $79. includes mount. cheapest way to go, next up being M3 then surefire forend.