I played around with 3 loads in my M-77MKII 350 Rem. Mag.
I have a 2x7 Leupold on there and have a good solid rest. BUT, so far I have not been able to obtain a good group.
57.0 grains of VARGET, 225 gr kodiak bullet, Rem 9 1/2 primer, loaded to 2.87col Average velocity 2,536fps. 23 fps extreme variation. VERY Dirty load. 2.3 inch group
56.0 grains IMR 3031, 225 Sierra gameking BT., Fed 215M primer, loaded to 2.900 col. Average velocity 2,688fps. 20 fps extreme variation. Clean load. 3 inch group.
55.0 grains H-4895, 250 grain Speer Spitzer. Fed 215 M primer. Loaded to 2.88 COL. Average velocity 2,537fps. 15 fps extreme variation. Fairly clean. 3 inch group.
I am not all that happy with the rough feed ramp of the action or the timing set of the magazine rails. This thing does not chamber from the magazine very smoothly.
The next step may be to free float the barrel away from the plastic stock. But it would be nice to obtain a sub 2 inch group first.