Squeezing Accuracy Out of the Mosin 91/30!

Travis Bickle

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So I decided I wanted to start a cheap project to occupy more time I can't afford :D
I opted for buying my 91/30 Mosin Nagant a couple months back.
She is a refurbed 1942 Ishevsk M1891/30 in average condition with an average bore.
As far as accuracy goes, these rifles are capable of some pretty impressive stuff.
Especially at the longer distances they were designed to be fired at. You can very effectively hit "minute of man" out to 600-700 meters with the irons and old surplus ammunition.
If you're lucky, you bought one that shoots very well. If not you bought one and found it shoots sewer lid + sized groups (my case).
I am not a fan of chopping up milsurp rifles. So I started doing some research on this subject.
I wanted to combine everything I have found which worked into one thread on here in case anyone wants to get more bang for their buck out of their old Communist War Stick.

1- Recrown the barrel.

This is probably the best thing you can do to increase the accuracy of the rifle. My crown was used rough and put away wet. There was clear damage from rough use with a steel cleaning rod. The circumference was almost egg shaped! :(
A weapon tech friend of mine put a new inverted crown on it with an 11 degree slope. A typical recrown will run you about $40-50 and this is the only cost any of this whole process will incur.

The new crown job.
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2- "The Trigger Job"

Part of the reason I found it was so hard to get consistant groups with this rifle is the ridiculous pull it takes on the trigger to release the cocking knob on the bolt and fire it. The design of this mechanism is probably the simplest of any around. There is a spring under the receiver, it runs through the trigger, on the end is a sear that holds the cocking knob back. Pulling the trigger bends the spring lowering the sear and releasing the cocking knob.
The best way to reduce the pull required is to shim the spring. I used an old expired OHIP medical card, it seems to be the perfect thickness and is flexible enough to mold to the round shape under the receiver. Just cut it to size and cut a small hole enough so that the screw can pass through on reassembly of the rifle.

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Now try it. The difference is unreal. It makes for a much smoother and crisper release. You may have also noticed that once the bolt is cocked, the trigger flops around like a wet noodle until you physically take up the slack. There is a way to turn it into a two stage trigger for free!
Get a clothes pin, a standard wood one with a metal spring. With a two pairs of pliers bend the whole thing as straight as you can.
You want to get it to look like this essentialy as a final product:

DSCF0801.jpg


The diameter of the hole should be as tight as possible so as to fit around the simple pin that holds the trigger in place under the reciever.
The easiest way to do this is to find a pole of equal diameter and use it as a jig to bend it around.
If you look at this picture you can get the idea of how it fits in place. I actually made my first one with a single loop as in the first picture. I then decided to try for a second loop to get more tension. It's not impossible but it's not for people who are short of patience lol One loop will still work fine.
Don't trim the long ends right away. Get the trigger pin through the loop(s) first then bend the spring up against the back of the trigger then clip it short. Like wise with the end that gives leverage. Make sure it ends up resting off to the side pressed up against the wall of the trigger guide wall or else it will impede the release of the sear. It should look like this once installed:

P4140296.jpg


Once you have it as tight as possible, assemble the rifle and test it a bunch of times before you use it with live ammo. I have fired over 100 rounds through mine since it has been installed and have had no problems. It works amazingly.

3-The Front Sight

The Mosin was designed to be used by unskilled uneducated peasant warriors. In most production cases they were never designed to be tack driving precision weapons with iron sights. They were designed to shoot high, some up to 16 inches at 100 meters (19 inches in the case of the M44 carbine). To unlock the impressive effectiveness of the Mosin rifles you need to push back to 300 meters or more which is the reason they were designed to shoot high. If the soldier aimed for center of mass at any distance he would still score a potential hit.
However, I prefer my rifles' POI to be where my POA is obviously. My 91/30's average mean impact of it's initial sewer lid sized groups was shooting very high, almost 24 inches at 100 meters! :(
So what to do. The rear sight will not go lower than 100 meters, so the front site post must go up! Like I said I did not want to do any permanent alterations and I tried to keep the cost as close to $0 as possible.
So, get yourself a small length of 12 guage insulated copper wire. Strip off the insulation by pulling the copper strands out a few at a time, carefully cut off the clear plastic sleeving. Each rifle will have its own required height of post to get your POI to match your POA. Marker the thing black to make it easier to pick up when using the sights.
Mine was about 0.8 cm but the idea is to cut it long and slowly shave off a sliver at a time with a sharp blade. Keep shooting 4 round groups until your vertical POI average is exactly where you would like it to be. I kept mine just a little high of my actual POA as I prefer a "6 o'clock" hold on my irons when I'm shooting.

In this picture is the actual 12 guage wire, The insulation stripped of the wire in the center. The front site "post" already has some insulation slipped on. You would barely notice the difference.

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Next you may notice that your average POI of your groups is off to one side or the other. Either way left or way right. This is an easy fix. The front sight is adjustable for windage. If your group is to the right of your POA, then use a punch and hammer to tap the whole front sight assembly to the right as you are looking at it while aiming! While holding the rifle as if you are aiming it, you will want to move the sight in the opposite direction you want POI to move. So if you want the POI to go left, you move the sight to the right! Vice versa if you want to move it the other direction.

4- Floating The Barrel

I can't say for sure if this really made a difference on my tightening my groups and accuracy but I gave it a go. I tried to "bed" the barrel using cork at first. After talking to my weapon tech friend again he convinced me of going the floating route. It is less work in the end.
Some Mosins may already have this modification done believe it or not. The Finnish would shim the stocks with metal or brass pieces on captured rifles to improve the accuracy.
Mine already had steel shims on the bottom under the magazine.

P4140288.jpg


If yours does not have the metal shims already under the magazine, you can use any thin metal material that is at hand. Just cut it to size, drill some holes and break out the JB weld.

Once this is done you will have to assemble the rifle.
Leave the upper handguard off.
Get a thick piece of paper and slide it (wrap it around the barrel) under the front of the barrel between the barrel and the stock. Slide it all the way up to the receiver. It should glide effortlessly.
If it snags anywhere mark the area with a pencil.

Dissassemble the rifle from the stock and start sanding down the inside of the stock in the spots where the paper caught where the barrel would sit (the barrel channel) with any grit sandpaper from 60-100 gr. BE CAREFUL IT WILL REMOVE WOOD FAST SO EASY DOES IT!
Reassemble and repeat the process until the barrel is not touching the stock in any area.
You will want the tip of the stock to touch the barrel. You should not be able to slide the paper under the barrel without pulling up slightly on it to get the paper between the barrel and stock cap initially.

If there is no compression on the barrel at the end of the stock, you can shim it with a flat piece of thin cork, or if you are really cheap (like me :D) you can use a piece of masking tape folded up to keep more pressure on the barrel in this area to hold it fast.

That's about it. There are other methods to smooth out the action etc but they involve polishing the bolt with grit sandpaper or dremels and I think this is not a very bright idea as it removes material from the one part of the rifle that has to have a relatively tight tolerance. I did not bother with any further tinkering.

This is the end result of my shooting my newly modified rifle. I shot 4 round groups the whole day while triming the post and getting used to the slightly thicker diameter of the 12 guage insulation, it changes the sight picture very slightly eliminating the spaces between the post and the sides of the notch in the rear sight leaf.

This 4 round group was about the best one I got all day.
I was using standard russian surplus ammo light steel core 7.62 x 54Rmm corrosive.
I shot this from about 150 meters from the prone using my dirty old range bag as a sandbag rest.
Not bad for a hastily manufactured 70 year old abused rifle with a dark, at best average bore.

I wish I had a picture of my previous groups before the modifications. I was barely on paper at 100 meters and my groups were all over the place.

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If anyone has any questions on how to carry out any of these mods should they wish to try them out, PM me, I'll be glad to guide ya!

Cheers!
 
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Great job Travis, thanks for sharing your tips and tricks.

Once my just-bought from Westrifle 91/30 gets here, methinks I'll be doing these modifications.

Mods, can we make this a sticky??
 
You have no idea how many mosins have loose screws & nobody notices.


Aye,
Lesser known ones are the one that holds the main tension spring down to the magazine latch inside the spring assembly in the magazine. The head of the screw is on the inside.
The other is the one just ahead of the trigger that holds the magazine plate latch in place.
 
Great job Travis, thanks for sharing your tips and tricks.

Once my just-bought from Westrifle 91/30 gets here, methinks I'll be doing these modifications.

Mods, can we make this a sticky??

The trigger mod is very easy and makes a world of difference.
I also polished the lug on the cocking knob that catches the sear with very fine steel wool to attempt to make the release more crisp.
I think it made a bit of an improvement but it might just have been psychosomatic :D
I can ship out a couple "two stage trigger" springs as I made a few before making the one I use now with the double loop.
PM me if you are interested or if you want to figure it out on your own that's cool.
Cheers!
 
Excellent job, Travis... I am working on one of mine in the same way. And the accuracy should be greatly improved with appropriate handloads too! ;-)

Would be VERY interested in your "two stage trigger spring" too...! ;-)))
 
Excellent job, Travis... I am working on one of mine in the same way. And the accuracy should be greatly improved with appropriate handloads too! ;-)

Would be VERY interested in your "two stage trigger spring" too...! ;-)))

I would love to get into handloading.
Especially for the 7.62 x 54R
But I can't justify the cash, time and space right now :(
I'm currently looking for someone locally who does load it.
I have a bunch of single fired S&B brass I've been hoarding lol
Hopefully I can find someone to make a deal with.
If you want one of my earlier springs PM me your address. I'll stick it in an envelope for ya.
Cheers!
 
Me and my dad were planning to accurize my Mosin and I guess I just got the thread to look on!

Honnestly my father isn't a gun enthusiast but the fact that it is a WW2 artifact ( 1939 91/30) really got him excited. I'm glad we agreed on this point (I'm in the army and he's a PQ member hahaha)

Anyhow, GOOD THREAD! I'll post my project check it out!
 
All those modifications will make a world of difference but for myself what really did cut the groups to around MOA was a tailored load with 170 gr .312 bullets just keeping shy of max load... JP.
 
If you want a more permanent front sight post solution, new ones can be easily fabricated using nails and cold blue. Once you've got a good front sight post height using the plastic tubing method, measure it, mark the front sing base's position in the dovetail, drift it out, remove and safely store the old post. Replace it with a nail of appropriate diameter, file to fit the base as required, cut to the proper height, cold blue, reassemble.
 
Can you explain a bit more what your doing with the front sight? Are you using placing the insulation over the front sight rod to extend it higher?
 
I have started in the same project.
My fist step was to remove the machine marks on the contact points for the trigger and trigger spring.

This in its self haves removed the feeling of sand out of the rifle.
 
Can you explain a bit more what your doing with the front sight? Are you using placing the insulation over the front sight rod to extend it higher?

Yes.

Basically, you are just increasing the height of the front post to bring your groups lower to match your POA.

There are other ways of doing it that are more permanent ie using nails, soldering, welding, filing etc but this is the easiest way that is also a non permanent modification of a milsurp rifle.

You will only need to do this if your mosin is shooting way high, which almost all of them do. If your Mosin is shooting very low then it is the opposite and your front post is too high to start and needs to be filed shorter to bring your POI to your POA.
 
Oddly enough I have a prewar refurb 91/30 that shoots low at 100 with the bayonet on. Great group but have to have the sight set to 200
 
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