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View Full Version : Squeezing Accuracy Out of The Mosin 91/30!



One Doomed Space Marine
04-14-2012, 06:38 PM
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.
http://i1208.photobucket.com/albums/cc364/WesLeeBronson/P4140306.jpg

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.

http://i1208.photobucket.com/albums/cc364/WesLeeBronson/P4140292.jpg

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:

http://i1208.photobucket.com/albums/cc364/WesLeeBronson/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:

http://i1208.photobucket.com/albums/cc364/WesLeeBronson/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.

http://i1208.photobucket.com/albums/cc364/WesLeeBronson/P4140303.jpg

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.

http://i1208.photobucket.com/albums/cc364/WesLeeBronson/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.

http://i1208.photobucket.com/albums/cc364/WesLeeBronson/P4140277.jpg

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!

frumpy
04-16-2012, 08:26 AM
Good read, thanks for posting up. Glad you got it all figured out.

Rory McCanuck
04-16-2012, 11:28 AM
Now its time to start reloading for it.
Load testing, fiddling.
Casting oversize bullets.
Slippery slope, my friend, slippery slope.

Don't worry, we'll help you over the edge..... ;)

One Doomed Space Marine
04-16-2012, 05:23 PM
Now its time to start reloading for it.
Load testing, fiddling.
Casting oversize bullets.
Slippery slope, my friend, slippery slope.

Don't worry, we'll help you over the edge..... ;)

lol I know!
I do not reload at the moment.
I'm currently trying to find someone in the Petawawa area that is set up for this caliber who can "advise me" on loading up a few for a couple bucks.
I'm really curious to see what I can muster up with some real ammo.

Rory McCanuck
04-16-2012, 08:53 PM
Bah, just jump in with both feet.
A couple load manuals, yewtube, goggle, and forums to read,
is maybe better than learning someone else's bad habits.
An inexpensive kit will get you started, and will have paid
for itself pretty quickly.
A more expensive kit will probably do you for a lifetime.
It might take longer to pay for itself, but using nice tools
tends to make any job less onerous.

stencollector
04-29-2012, 07:31 AM
That's a nice group for iron sights and surplus ammo.

I have found that my Polish M44 likes 56 grns of BLC- (2) under a 124 grn bullet. Hornady make them, but pulled bullets from 7.62 x 39 rounds works jut as well. These loads shoot flat as a pankake.

http://i179.photobucket.com/albums/w315/Orriblebastard/IMG_1519.jpg

webster
05-04-2012, 08:59 PM
Awesome post! I may have to try some of these tricks. :)

stencollector
05-04-2012, 11:18 PM
I found that my M44 shoots crap with the bayonet removed, I think it's due to the fact that it has a floating barrel, and the weight of the bayonet dampens the vibrations by stabilizing it.

BTW the load I mentioned above makes bystanders very uneasy, it produces a very big orange fireball even on a bright sunny day. People think that the rifle is going to blow up, but it's really quite safe, there are no signs of excessive pressure shown on the spent cases.

Stephen
05-06-2012, 02:35 PM
My dad used to be very deadly with his. I'll shoot it more when I set my realoading equipment up.

Deniici
07-15-2012, 11:12 PM
Great post, I'm gonna have to try this on the M-44......thanx for the tips.
Stencollector, that's a beaut of a rifle.

Garetsu
07-16-2012, 07:35 AM
Oohh....

I think I'm definitely going to have to do at least one of these. The crown on my barrel is good, luckily, don't need to do anything there, but I definitely want to do that trigger job. The stock trigger pull is just painful, haha! Plus, it's pretty easy looking to do, which is also good for lazy people like me.


I'll have to do the mods before I go out to the range, next, so I'll have a before/after picture of my 100m targets, and maybe punch a hole in the 180m target for once. :-P