Well... to begin with, there is (what I would consider) "a proper" way and the "other ways".
Depends I guess on what you are looking to do... make a reproduction type rifle... or what?
Also, I assume that if you are looking to make a "reproduction", that you are talking about a 91/30.
look around on the web and find some pics of Mosin sniper rifles, notice the scopes... notice the mount?"To create the sniper version of these rifles, high quality examples of the 1891/30 were pulled off of the production line. They specifically looked for high quality barrels. They took these hand picked rifles and then turned the bolts down for operation while using a scope. They mounted a scope; both the PV (4x) and PU (3.5x) versions were used. The PU was preferred and used on most of the sniper versions. There was no bayonet issued and the foresight was raised 1mm, which allowed the open sites to be used out to 600 meters. The trigger was also lightened to 4.4-5.3 lbs (2-2.4 kg)."
Google Mosin Sniper... and read. You could start here: http://www.russian-mosin-nagant.com/sniper.htm