I have the same rifle and put a Vortex Spitfire 3x on it and love it. I was going to go with the Strikefire, but my eyes aren't what they use to be so the 3x helps.
http://www.vortexoptics.com/product/vortex-spitfire-3x-prism-scope-with-ebr-556b-moa-reticle
http://www.vortexoptics.com/product/vortex-spitfire-3x-prism-scope-with-ebr-556b-moa-reticle


















































