Building a super mosin….

I’ve been lazy about posting for a bit due to holidays, trying to get a piece of property, work, ect. Posting should pick up again, unless I get that property then I’ll be moving stuff.

I have been busy out in the garage, working on various projects. Lately it’s been a mashup of small things from the hit-miss motor restoration to model engines and firearms. I took a series of pictures on the latest Mosin Nagant 91/30 overhaul and figured I’d share them with everyone. The 91/30 is a WWII era Russian rifle, the one in the pictures was made in 1936 and bought surplus from a box store. Firing one of these in it’s as-purchased configuration is painful, it kicks solidly and the buttstock has a metal plate on the end. Somewhat uncomfortable on the shoulder after a few rounds. Also, it doesn’t have any place to put an optic on it as it came from the factory unless you want to use a WWII era PU scope, which I dont. Optics have come a long way since the 1930’s, and even a ‘cheap’ optic made recently is easier to see through and use.

On to the pictures and descriptions…..

There’s the basics of the rifle with the bolt removed and taken out of all the woodwork. Not a lot of parts there, basically the trigger, trigger spring, chamber and barrel. I will be doing a trigger job, installing an optic rail, changing the bolt handle, refitting an M1944 muzzle break to fit the 91/30 and installing it, putting it in a more comfortable stock, and putting a bipod on it. To give you an idea how radical the change is here is a before and after of a previous super mosin I built.

As you can see, it’s a tiny bit o’ difference.

Time to get the trigger out for a little modification. The trigger is held in by the trigger spring, which is held to the gun by that big screw in the middle of the pic, and a pin that acts as the trigger pivot. Thats it, remove the screw and the pin and everything comes out. What those parts look like….

The trigger spring is on the left, trigger on the right, pin and screw in the middle. The trigger spring passes through the trigger out the other side. That weird block on the spring is the sear, when the trigger depresses the spring enough it releases part of the bolt and the firing pin sets off the cartridge. The problem with this is that there is usually a gap between the trigger and the spring, allowing the trigger to just kinda flop around before making spring contact. I don’t know about you, but that annoys the shit out of me. Floppy triggers suck and need to be fixed. Fortunately, a little time and a set screw can go a long way to remedy this situation. First we need to get the trigger in the mill (or a drill press) to drill a hole.

Trigger is in the vise, wrapped in a surplus business card from my last employer. No need to mar 70 years of patina if I don’t have to.   😉    Next comes a center drill to make sure I place the dimple in the right spot and get a good penetration on the surface for my drill bit. Center drills arent expensive, they are very rigid, and they beat the heck out of trying to start a hole with a drill bit wandering all over trying to get a start. Buy them, use them. On to drilling the actual hole.

In case anyone is wondering, I’m going to install a 4-40 set screw. Go bigger if you want, I don’t think it will hurt anything, I just have always used 4-40. I typically use a HSS numbered bit for drilling tapped holes. Tapping charts are available everywhere to download so I won’t get into numbers. Once the hole is drilled, time to tap it.

Whoo hooo, the joys of free hand tapping. Slow is best, break off a tap in that hole and you’ll be shooting with a sloppy trigger, guaranteed. Once again, retired business card to preserve the patina. I use a tapping compound to keep the threads going smoothly, picture of that later in the series I think. I also use mineral spirits and an old toothbrush to clean the tap about every two full turns , it gets the grease and any trapped debris out of the cutting threads and helps prevent chip binding. Learn from what I say, don’t add to your scrap pile by repeating mistakes I’m trying to help you avoid.

Once the hole is tapped, put a set screw in it and reinstall the trigger. Access to the set screw is through the receiver from the top with the bolt removed. Even without the bolt you can adjust the set screw and get a feel for the adjustment possible on the trigger. I usually take the slop out of the trigger, install the bolt, feel the trigger break, and then remove the bolt and make adjustments as needed. Once I find my happy place, a drop of green (bearing retainer) loctite keeps it from changing.

By the way, here’s a pic of my loyal shop companion. Usually hangs out right by my side through all of my workshop time keeping me safe from roving bands of shopping-cart-pushing zombies.

I bet you thought it would be a dog……. lmao! Next post, optics rail.