I can't find a Ruger rmr. Are you referring to the Ruger precision Rifle?

I think that would suit you better than the American. I have the American predator and it is a great hunting rifle. It is light and I can carry it all day. For long range shooting, I very much prefer a heavier rifle and one where I can adjust length of pull and comb height.

The 6cm would be a great round for your purposes. Just keep in mind they tend to have a short barrel life. 2000 rounds ish depending on how hard you push them.

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