I have a mini 6.8 new. I bought a prostaff Nikon 3x9x50 BDC scope for it but now I think it might be too big. What do you guys think? Are there better choices? The scope rings, size 5 are too short for this scope. What size do I need? Is there any specific rings you think would work better than the Ruger next size larger rings? Thanks for your help.