My used $1200 MR1 came with a Burris 3-9 already mounted and the rear sight detached with the screws missing. Since I wasnt a fan of the iron sight setup on the gun to begin with, and my intended role for the gun was purely as a semi auto varmint gun. I did the unspeakable and CUT the front sight completely off! To solve the eye relief issue, rather than buying the ATR rail (which I didnt know about at the time), I simply bolted the original rail on backwards... That gave me the ability to mount the scope at the perfect eye relief. Because the front sight was removed, I was also able to the mount the optic super low, offering bolt gun height over bore characteristics. It turned out pretty slick IMO
As for optics, what it wears now is a $340 4-12x42mm Nikon P223 scope. Im a huge fan of Nikon optics because they are affordable, come with a 30 yr warranty, have great glass, clear reticles AND easy to reset turrets. But knowing what I know now, I WOULD NOT recommend this particular scope because the
turrets are exposed on it. Which means they can be bumped and therefore your zero lost when you least expect it... this cost me probably 3 coyotes in one go around once lol.
My recommendation instead would be just the plain $260 Nikon 4-12 or 3-9x42mm Prostaff 5. It is the same as the scope mentioned above except it doesnt have the .223 REM BDC reticle...
BUT IT DOES HAVE TURRET CAPS 
I had one for like 2 years beating around on my SKS and it function perfectly the whole time! shouldve never sold it.
These pics all have the Burris scope that came with the rifle mounted to it. The 4-12 Nikon sits waaaaaaaaay lower... like maybe 1/8" clearance between the OBJ lens and the forend.