As we go through each component of our rifle, we find little things can be improved with little or no effort. The trigger assembly in a Mosin Nagant is very simple. Some people prefer the original, unworked trigger in a milsurp gun. I guess a completely “authentic” trigger is part of the experience for purists. As is obvious, we are modernizing and modifying our milsurp. Anything that I can do to improve it, I will. Mosin triggers are not nice. Late WWII productions are particularly rough.
The first thing to do is to remove the trigger assembly from the action.
Use a flat bladed screw driver to remove the screw as shown. This screw holds the trigger spring and bolt stop into the rear of the receiver.
Once this is removed, remove the trigger hinge pin. I found this came out pretty easily, but there is a lot of variation between rifles. Some pins will require the use of a punch. I used a ball-point pen.
This is what the parts look like when removed.
Be sure not to lose anything! If you do lose something, I have found that these parts are usually available online. That said, losing things is aggravating. If you can help it, don’t.
Next we need to inspect the mating face of the bolt stop. My apologies for the fuzzy picture. Nonetheless, it can be seen where I filed the surfaces down. The front and top needed to be shaved by just a hair. One thing many Mosin triggers share in common is that the bolt stop and the cocking piece do not mate to each other in a square manner. This directly causes the rough trigger. One method of determining if your Mosin has this problem is to cock the rifle and then take up all the trigger slack. Watch the cocking piece very carefully as you take up the slack. With an unadjusted trigger you will see the cocking piece slowly creep upward as you continue the trigger pull.
I used a sharpie to mark the mating surfaces on the cocking piece and bolt stop, then cycled the action several times and dryfired the weapon. Then I disassembled everything again, and inspected the cocking piece and bolt stop. Everywhere the ink had rubbed off shows where the surfaces made contact.
Then I took a small file and some 600-grit sandpaper and filed the mating surface square. Apply very little pressure. You do not want to remove too much material. Then I sanded the surfaces to a shine. You can see how the bolt stop and cocking piece go together below. In the second picture I inverted the bolt so it can be seen clearly.
Reassemble the rifle and dry fire it to see if the improvement is sufficient. Repeat the process as needed, but remember not to take off too much material.
There is a test that you can run to see if too much material has been removed. First, reassemble the trigger assembly. Do not put the barrel and receiver back into the stock. Holding the rifle by the barrel with the muzzle up, firmly strike down onto the floor or some other wooden surface. If when the tang strikes the floor, the gun fires, you have removed too much material.
Next we look at the barrel, and how to shorten it…