ORIGINAL: salukipv1
leupold vx-ii shotgun model 2-7, I think they may make a 3-9, really I don't think you need any scope other than a 1.5-4.5 or a 2-7, just get some solid mounts and I think you'll be fine.
If you're that concerned get a vx-7 1.5-6 it'll take abuse I'm quite sure.
+1
I have this exact scope on my 870 w/ cantilever. After some technical difficulty w/ the gun, I gave shot over 30 rds through it w/o failure