'39 Tula Mosin cleanup and upgrades

BCRider

CGN Ultra frequent flyer
Rating - 100%
33   0   0
Location
The 'Wack, BC
I couple of weeks back I posted about getting my new Tula and a couple o' SPAM cans full of ammo.

When I used some mineral spirits to slew away the cosmo it also took off some pretty big patches of the shellac as well. CURSES ! ! ! ! ! !.... OK, let's get out the coarse steel wool, add some lacquer thinner to the mineral spirits and strip it down. Got it down to the wood with a bit of elbow grease and the solvent.

Stained it with some dark brown leather dye and after it dried for a few days I used a couple of coats of polymerized tung oil on the wood. Still need to do two or three more coats. But as you can see from the picture below it's not too shabby looking for military wood. It's a little darker in real life. The flash lightened up the wood by quite a bit. More of a darker coffee with just a little milk sort of look.

Over the past couple of days I did some small upgrades.

First was to pack the sear/spring with a "washer" cut from some of the soft steel pipe hanger strapping.

Next was to eliminate the floppy trigger by making and installing a spring that pushes the trigger back. Now it stays lightly against the sear instead of flopping around as with stock. And the roughly one lb of positive trigger pressure slightly aids in reducing the trigger pull. I need to get a "fish scale" to measure the pull but it seems like it's around 6 to 7 lbs as it sits now. These two mods of packing the sear spring and the trigger tensioning spring worked so nicely that I'm going to do the same mods to both my M44 and the '43 Izhevsk 91/30 as well.

The points where the trigger rubs the sear spring and the sear to bolt hook surfaces were stoned to polish them with a super fine ceramic knife sharpening stone. As a result the trigger has a nice smooth pull with no "gravel" feel up to where the sear breaks with a snap.

The forestock end was resting against the barrel so I made up a thin shim and put it into the forward screw recess in the stock. WIth that the action seated down with just about a millimeter or less of movement needed for the front of the stock to touch the barrel. I "corked" the stock using a single layer of file folder card stock. This produced a slight amount of friction to pull the foregrip into place. Over the top I had to add two more layers to allow the upper cover to push evenly all around the barrel. So now the barrel is free floating other than the "corked" point at the forward stock band. Does this sound about right?

Finally the rear sight was fixed up. The groove was slightly widened and deepened to almost double the stock depth. My old guy eyes need this sort of help or I may as well stand back and just throw the bullets by hand for all the accuracy I'd have. With the groove widened slightly and greatly deepened I can see the front pin centered between the sides of the rear groove far more easily and the top corners of the groove are far easier to line up with the top of the pin.

Front sight body was bumped over to center it on the mount to hopefully compensate for not normally shooting with the bayonet in place. Further bumping will wait on results from range testing.

The hinge pin was punched out and the blade and elevation adjuster removed for this U mod. At the same time I filed off a fair amount of metal from the lower bevel edge of the adjuster body so it should hopefully shoot lower for the closer in stuff. The notch and adjuster body work were then cold blued to touch them up along with cold blueing the new refurbished muzzle crown.

The picture here was taken once it was all back together. Now for a sunny day to take it to the range and try it out.

010.jpg
 
Isn't it better to try it stock to see if you are helping or hindering the accuracy?

The only part that'll possibly hinder it is the "corking". The rest is an iron clad cinch that it'll help since it turned a trigger that needed something like a 15 lb pull into one that needs around 6'ish. And as mentioned with my eyes I could barely see the rear notch. Let alone use it to aim. So that too was an iron clad improvement.

I wanted to at least get the shims sized for the "corking". They aren't glued in place at all so they are easily removed for a back to back trial. Which I'm planning on doing to see if it does help or hinder. Putting them in or taking them out is nothing more than slipping the barrel shroud bands off then on.
 
I just finished making up and installing the same shimming on my M44. This time I took pictures.... :D

The main part shows the trigger with the sear spring shim and tensioning spring installed. In front of this is samples of the pipe strapping and an additional shim already made up that I'll use for my '43 Izhevsk. Also you can see the tensioning spring that I made from 1/32 music wire. The block of steel with the drill and pin stuck into it is the quickie jig I made up for winding the coil. The coil being 2.5 turns around the 5/32 drill bit shank. The pin that holds the wire is a 1.25 inch finishing nail drivven into a 1/16 hole then cliped off and filed down so it sticks up just a touch more than 1/32 inch.

The pop can metal and shim is what I used for fine tuning the front mounting lug seating height. The pop can metal punches out nicely using just a regular 3 hole paper punch and the holes are just a nice bit bigger than the bolts that hold the Mosin action together.

Mosinmods.jpg
 
That spring looks the same as the C & R Surplus Spring LLC design. That's OK though cause they won't ship to Canada.

Our two springs actually work totally opposite. The C&R spring pushes the trigger forward so you have to pull through the pre-travel. My tensioning spring puts the trigger back in light contact with the sear spring so as soon as you move the trigger it begins moving the sear. No pre-travel at all.

I saw where the C&R spring was said to have a "two stage trigger". The thinking being that the useless pre-travel is a "preparation" stage before the trigger actually begins to move the sear. Yeah, about a half inch of "preparation" before it does anything at all. Once I read what they meant I had to laugh a little at the idea of making what I consider to be a failing into a feature.... :D
 
I do like your concept better. I can understand the need for long two stage triggers in military thinking, but for us plinkers I prefer a nice single stage any day.
I set mine up like the Finns did. Optimized the sear angle, bend the spring a little and polished the contacts. From a 12lb gritty pull it's a nice 3lbs with just a bit of takeup I can live with. I don't need any shims that way.
 
I saw a video of a guy that bent the sear spring to reduce the pre-load. And now I see you makin reference to it.

Given that I've had some issues with leaf springs in the past and that sprung parts such as this on SAA style guns can fracture from being overly bent I opted to stick with the shimming idea to reduce the sear pre-load.

An interesting thing I noticed with my M44 that was made in 1953. First off the machine work is of the very highest quality. This rifle is REALLY NICE! Even the back side of the sear spring that is the target for some polishing came from the factory pre-polished. Also the engagement face of the sear hook was also polished.

How do I know it was done at the factory? When I took it apart the cosmoline grease was still packed in around the sear spring and trigger base. It was a MESS in there!

After reading more about the corking/shimming aspect I'm going to try shooting it with the shims removed. I shimmed the action bolt points such that the barrel on the '39 Tula is actually free floating by a touch more than the thickness of some writing paper. So it's worth trying it like it is first. I'll likely then put the corking shim in and see if any improvements can be made.

The M44 is pressing slightly to one side at the muzzle against the wood. I'm going to slightly sand out the barrel channel and try some half shimming in the action screws to see if I can tilt it by a hair in the stock and get the barrel free floating as well.
 
Back
Top Bottom