Making the scope on your Mosin Nagant stay put

The Mosin Nagant is a rifle first built by Russian and French firearms designers in the late 1800's. It's a reliable weapon and was used in the Russian military before and after the revolution.

Today, the surplus firearms market is saturated with these firearms, which are typically on display by the case at local gun stores. Their caliber (close to .308) allows them to be used for cheap hunting rifles, and they are pretty accurate, reliable, and tough.

The challenge with these firearms is that the 3/8 sight rail is a bit anemic for mounting a scope. A common problem with them is for the sight ring screws to loosen up after a few rounds (even with locktite).

This instructable documents my 3rd (yes third) adventure in mounting a scope to my Mosin Nagant M91/30.

Note: This documents me making permanent modifications to a firearm. I am NOT a professional gunsmith and am not responsible in any way if you make modifications to your firearms. If you are not comfortable with the modifications in this instructable either structurally or for retaining historical value...don't do it! If you perform this modification...IT'S ON YOU !

Step 1 Required hardware

For the hardware, steel is ok. I like to use stainless steel, but couldn't find it in such small hardware.

(4) Metric #4-.70x12 Cap Screws
(4) Metric #4 Wave Lock Washers
(4) Metric #4 Split Lock Washers
(2) 10-32x1/4 Set Screw
(1) 1/16 Allen Wrench (or whatever fits the set screw).
(1) Tube of locktite.
(1) 10-32 tap
(1) #21 Drill bit
(1) pair of medium height 3/8 dovetail scope rings (I used the cheap NCStar ones off Amazon).

With the sight rings, but not including the scope, I have about $15 in the mod.

Comments

[tyeo098]

Id just tap the receiver so I wouldnt have to deal with long eye-relief scopes.
Neat 'ible though, Locktite is very useful!

[Tinker83]

the trouble with tapping the reciever in a 91/30 is that the bolt action is at a square angle. you'd have to either replace the whole bolt, or have a smith bend it down to something like 60* which is absolutely horrible to work with.

[rizingf3nix]

ATI actually has a great kit that includes a bolt handle and rear sight mount with very good instructions. Anyone with simple machine skills will be totally comfortable with the installation. It also holds a full scope quite well.

[nickitzi]

One problem I find with this mod is that you are using rimfire scope mounts on a centerfire gun. What I would recommend using a universal weaver mount and drill and tap four 6-48 screw holes and remove all possibility of scope shift,
most rimfire mounts lack any real holding power even on the intended gun the use of set screws is a old gunsmith kink. PS I think it is great you did not use the worthless rear sight mounts.

[rizingf3nix]

The scope setup of the platform in general doesn't give many options short of diy gunsmithing, which at the time I wasn't comfortable with. Since this instructable, we've put about 300 rounds through the gun and it still hits where expected. Nothing has loosened up, but I would agree that rimfire rings aren't the best thing for it. So long as they hold...

Ironically, I've recently purchased an M44 (carbine version of a 91/30) and fit it with the ATI rear sight mount, subsequently putting about 20 rounds through it. The accuracy was astounding (using a Russian VOMZ scope) and I prefer shooting through it rather than the 91/30. The sighting for the scope mounted over the bolt feels more sure of itself. I'm looking forward to fall deer season with this gun.

[tyeo098]

Also, your mosin could use a good refinishing with something other than 100yr old varnish!

[Tinker83]

that's not varnish... thats cosmoline...

[rizingf3nix]

Update on the scope mod. I've since put about 100 rounds through the rifle, and the scope is still holding zero.