Mosin-Nagant Trigger Mod

[TMan]

As I mentioned in another thread, I added shims to my Mosin-Nagant (MN) using the procedure described in the following link:

surplusrifle.com/shooting2005/mosinnaganttrigger/index.asp

My MN is the "sniper" version and has the holes where the scope mount was mounted, filled in with some sort of metal.

Prior to modification the trigger was breaking at 5-3/4 lbs on the RCBS scale (don't ask where my digital scale is ), and it was very creepy

My first thought of using the metal from floppy disks didn't pan out. It would have required too many shims. So, I picked up some sheet metal at Home Depot that they use on roofs.

I drilled the holes in the sheet metal first, using a 17/64" drill bit. I then cut the shims using tin-snips.

After a few trys, I determined that 4 shims would give me the most practical adjustment - or so I thought.

Then using a Dremel and Flitz, I polished the sear and the part on the bolt that the sear contacts.

After adding the shims, I found that the trigger pull was now 5-1/4", which was disappointing, but I'm thinking that is because of the spring that is in the bolt. However, all of the creep was gone.

Today at the range, the first 15 rounds worked well. The groups weren't as tight as the Mauser or Swiss K31, but better than they were prior to the modification. Round 16 was okay, but then when I pulled the trigger for round 17, it didn't fire because the bolt wasn't cocked. Looking at the trigger, it was obvious that it didn't reset. Just a little nudge and it reset ok.

So, I'm going to take one shim out and see how it does.

[TMan]

Actually, on close inspection, the problem was that the trigger was rubbing up against the side of the trigger guard. So, after a little filing, it went to the range today and worked flawlessly. The very first round was a flyer, I'd forgotten that there wasn't any take-up anymore, and it went off before I was ready. The next 19 rounds were in the center.

One of the nice things about the modification is that there is no permanent change to the rifle. Well, if I shim it anymore, then the bolt will fall out. So, I think I'm going to stone a little off the bottom of the bolt because I can feel just a little creep.

[MLB]

While polishing parts doesn't concern me too much, I'm always worried about stoning anything too much. I need to invent an "unstoning" stone that works like an "undo" button.

[5ontarget]

tman said:

So, I think I'm going to stone a little off the bottom of the bolt because I can feel just a little creep.

When I first read this, I thought, what good is stoning the bottom of the bolt going to do? Then I got to looking at the bolt of my M38 I have out on the floor(don't ask why), and realized what/where you were talking about.

On a similar but different vein, we had some strong sustained winds here a couple weeks ago. It proved too strong for some of the metal roofing on one of the old barns. It was so badly damaged, that it could not be salvaged. So I got busy with some metal snips, and my rivet gun, and now I have a make shift E-Z bake rifle oven for cooking cosmoline and warming/backing on finishes. A couple of 100W bulbs warm it up nicely. With the weather around here recently, I'll have to put a blanket or two over it to boost the heat for the finishes, but it gets plenty warm for melting cosmo. I got the idea from www.surplusrifle.com/shooting2006/lowheatmethod2/index.asp except mine is longer/bigger to easily accommodate something as long as a 91/30.

[TMan]

Armed with stones, the Dremel, and sheer lunacy, I pulled out the bolt, disassembled it, threw caution to the wind and started on the cocking piece.

Then some amount of sanity struck me and I stopped, checked Numrich gun parts, and went back to work. (Numrich has the cocking piece for $7.65, and it isn't a part with the serial number on it.)

The stone on the Dremel took the tab down quite quickly. I should have measured, but it looks like I removed about 1/3 of the metal.

Then I stoned it by hand to smooth it out. On closer examination, I could see that the engagement surface, although was polished to a mirror finish, wasn't completely smooth. So, I applied some Dykem and started stoning the engagement surface. It didn't take too long, and then using the Dremel and Flitz, I polished it to a mirror finish.

Before putting it back together, I checked again and found out the Numrich carried the trigger spring for $5.10. I then cut off one turn on the spring and stretched the spring out a little bit. I'm not using government surplus ammo, so I don't think the primer strike needs to be as hard as it has been.

End results: I didn't have to remove any of the shims, which pleased me because I didn't have to take the rifle off the stock again. There is no longer any creep and it is breaking at slightly less than 4 lbs. Not bad for a military trigger.

[5ontarget]

tman said:

There is no longer any creep and it is breaking at slightly less than 4 lbs. Not bad for a military trigger.

Not bad indeed! I'd say that is excellent, especially for a Mosin-Nagant.

My 91/30 actually has a pretty good pull.

So, is it a single stage trigger now too? Did you take the notch/bump out of the trigger?

[TMan]

Hmmm, now I'm not sure which model I have. There wasn't any notch or bump on the trigger. The spring goes through an opening on the trigger. When you depress the trigger, it pushes down on the spring, which moves the sear, since it is part of the spring.

After shimming the spring, it introduced a lot of take-up, which of course is still there. However, there is no resistance to the take up i.e. it is in ounces. Then the stop, and you pull and once in awhile you can feel a little bit of a creep, but mostly not.

Incidentally, I only shot 10 rounds today (shoulder), but it was the best I've seen this gun shoot. The trigger does make a difference.

[5ontarget]

My mistake I was getting th MN trigger confused with the Mauser trigger. To make it worse, By taking the bump off, pretravel would be increased on the mausers. Sooo, forget I said anything. My brain must have been working even slower than normal.