id be surprised if your clearance problems came on the back side with the bolt....ive gotten to where i use one piece mounts pretty much on all my guns (dednutz, talley, rws, etc), and the 2 issues i usually run across is either the scope not clearing the blade sight in the back, or if i go with a high mount, the scope not having enough adjustment down to match up to the rifle at closer distances. I think the standard logic is go with a mount that puts the scope as close to the barrel as possible. What size scope are you putting on? Usually you can get away with a low or medium until you get past 40mm and then youre looking at a high mount.
I'm placing a Leupold VX-II 3-9x40 on the Savage 220F, I know a person with this shotgun and has the Dednutz 12200 (high) without an issue and he has about 1/2" of bolt clearance, I emailed Dednutz they said I could use the 18200 (medium) I like to get as close to the barrel as I can
whitetailcrazy, thanks for info on the medium height, I was going to go with the high, but happy I went with the #18200, getting it mounted, bore sighted after the new year