Take a look at this other thread also with a post from ErikZ's: https://www.hkpro.com/forum/hk416-hk4...mr762a1-2.html
Based on his suggestion and some of my own research I went with the same mount for my MR762A1 and Vortex Razor HD II HD 4.5-27x56. It is a Geiselle AR15/M4 Mount with 20 MOA. They were on sale this past weekend. It is rock solid, easy to mount the scope on and excellent return to zero. I checked that out this weekend shooting out to 980 yards. Zeroed the scope at 100 yards, removed it and mounted it back on at the range. Plugged in the distance into Ballistic AE and the elevation was spot on. Had to adjust for wind, but was getting hits at that distance.
I have a quick detach Burris on one of my other scopes, and it really doesn't seem to buy you much. It isn't that much quicker. Having tried both types, I wouldn't go with a quick detach. The Burris did have a good return to zero, but I only tried out at 100 yards....so not as sensitive to error.
Here is a picture of my setup...by the way, tech support at Geiselle suggested the same mount vs. the AR-10 one. I think it gives more flexibility with the mounting. I have the scope all the way back on the rings and all the way forward on the upper....that way I can move it back on the upper as I adjust eye relieve w/o having to remount the scope.