Mk -M-GOBL, The 454 would be a great choice. I dont know what you have shot with before, but the.454 does have a fair amount of recoil. However its pretty managealbe with some practice. As far as barrel lenght I would be happy with the 7.5 in barrel but thats just my personal preferance. For a scope mount which I use on my F/A and recommend is the SSk Tsob mount (3-4 rings) providing they make them for the Ruger. I would recommend a good scope such as a luepold or Nikon. Hope this helps..Jeff