I've used 2 Nikon Prostaff 2-7x32 shotguns scopes, a VX2 2-7x32, Nikon Monarch 1.5-4x20, and a 3200 2-7x32 on shotguns. My main rig is an 1187 with 24" Hastings CL FR bbl and the 2-7x32 3200. It's pretty picky on sabots, but shoots the Win PTGs and Rem CSs fairly well(1.5-2" @ 100).
I just bought a 23" FR CL bbl for an 870 and intend to mount one of the Prostaffs on it. Have SSTs, Rem ATs, Fed BEs, and Win PTGs to try in it. I hope it shoots more slugs accurately than the Hastings bbl, that Hastings bbl will not keep some sabots on the paper at 100.
If you are looking for 200yds, I'd go with a MLer or the Savage bolt action 20ga. When we hunt IA I usually carry my ML10 or Omega for stand hunting and the shotgun for drives.
Good Luck
loder
