My best answer is call tech support for whomever you are ordering from and let them tell you what definitely will work instead of us just guessing. They have computer programs and charts with all those variables plugged in. My guess is low, but who knows if I am right? When I need rings, I call Midway or SWFA and tell them exactly what I am putting on what, and I tell them I want clearance, but bare minimal clearance between the bell and the barrel; they always give me just what I ask for.