Rock Solid mount, or what I used- a Weaver Side Mount as shown below.
You need the skill and equipment (drill press) for the d&t mounts.
I made my own bent bolt, not difficult if you have a welder..
Made pillars from steel rod, epoxy bedded the receiver into a Boyd's stock.
Timney trigger.
Cut (22") and re-crowned (11 degree target crown) with a PTG crowning tool.
Shoots sub moa with SMK handloads.
Good ideas, here:
http://www.gswagner.com/mosin-nagant/mnsporter.html