Accurizing A Mosin-Nagant

Discussion in 'Curio & Relic Discussion' started by Joshua M. Smith, Mar 29, 2011.

  1. Joshua M. Smith

    Joshua M. Smith New Member


    Author's note: I wrote this in response to a question asked at The responses were such that I thought maybe someone could benefit from it as an article instead of just an answer, so I'm sharing it out as such.

    I've been getting asked on the board and via PM how I accurized my MN 91/30.

    With all due respect to N_K_1984 and his hard work, I do not believe that the answer lies in floating the barrel. I'll get to that in a minute.

    First, torque the action screws to 50in-lbs and shoot the rifle. It may be good the way it is! The PU snipers were just ones pulled from the line because they demonstrated better-than-normal accuracy.

    If you're unhappy with the accuracy, you'll need to shim the sear spring/trigger/return spring. They're the same thing. Pull that piece out. While it's out, dress the sear down with a fine stone -- I like to work up to 600 grit for this, but any fine stone should work. Just don't change the angles! Also, stone the area on the sear spring contacted by the trigger. It's all very easy and straightforward.

    Next, get a piece of shim stock. It should be 0.020" thick or so. Cut it to fit, drill a hole, and install it between the sear spring and the action. Do not go overboard; you should have an 8lb pull that resembles a revolver trigger. Any less, I consider dangerous, and if it's smooth, it doesn't feel like 8lbs.

    Go shoot it. The improved trigger will help you get the inherent accuracy from your rifle.

    Now, with regard to the barrel, there are two schools of thought: Floating and bedding. I am usually in the school that says “float”, but the barrel of the Mosin-Nagant is really too thin to float well.

    With apologies to N_K_1984, I will pick on his targets because he has the most awesome sporterized Mosin-Nagant I’ve ever seen. However, it needs improvement and this may help him some, too!

    I believe this to be the first target he shot. The reason is that the three-shot group near the bullseye speaks of a cold barrel. However, as the barrel heated up, it threw the last two a bit high.

    In what is probably the second target, you can see how the circle becomes pronounced.

    I am guessing this is the third target shot. It shows a heated thin barrel: It’s shooting large rings.

    Floating a barrel is great, but only if it’s not skinny. A fix for this barrel would be a de-resonator about an inch in front of the stock, and a series of o-rings rolled down the barrel to the end, all touching. As is, the circles are not a whole lot bigger because the “cosmetic” thing he has hanging off the barrel’s muzzle is acting a bit like an old BOSS unit (it’s really doing something there, man, not just decoration as you stated in another thread!)

    The next option is to bed the barrel.

    1. Go to Autozone. Get thin cork gasket material. It should run you about $5.
    2. Sand the barrel channel smooth, cut a strip of cork gasket material, and lay it in the barrel channel.
    3. Put the barreled action back in, and cut off the excess cork wherever you see any.

    Go shoot it. The bedding is allowing the stock and handguard to act as sort of a heavy target barrel. That’s not exactly right, but you won’t be shooting circles and the harmonics will be way down.

    Now, bed the action. Just pillar bed (instructions of all sorts are on the Web), heck, I just cut more cork and put it between the points on the action where the screws enter and the stock, then torque to 50in-lb. You just need known pressure points, not random ones.

    The rest really depends on the ammo. The 7.62x54r uses .311” bullets, while domestic ammo uses .308” bullets. If you want accuracy, you’re going to have to go with Priv Partisan or S&B. You can reload these cases too, and .311” bullets are readily available as are dies and reloading data. If someone will measure a 7.62x54r from Winchester, please post it. I may be wrong in that it’s still .308, but it was about five years back.

    I hope this helps someone.


    Copyright© Joshua M. Smith. I don't give a tinker's damn if you share this out or not; the "©" thing just seems to be in vogue right now! Haha!
  2. jpattersonnh

    jpattersonnh Active Member

    Joshua, I have read many threads about accurizing a 91/30. Your trigger approach is standard, there are some that do more work in that respect then you. It seems to work for some. Any rifle that has a barrel that is surrounded by wood is going to be less accurate compared w/ a floated barrel in a modern bedded stock. My experience w/ the 91/30, M44 is that both shoot heavy ball better(180gr). Surplus light ball weighs between 147 and 152 gr's. Light ball also has a hollow cavity in the nose of the bullet. The dimensions of a heavy ball and light ball bullet are almost exactly the same, but w/ that cavity the light ball takes more time to stabilize its' rotation. The higher BC of heavy ball makes it more accurate. The rifle tends to be secondary in this case. I'm good w/ hitting a milk jug at 100 yards w/ light ball. That goes to 200 w/ heavy ball shooting both off hand. If you want real accuracy in a 91/30, get a Finn. They knew more about accurizing these rifles then we will ever know. I'm ok w/ 4" groups w/ light ball or 2" groups w/ heavy ball. My PU w/ 2" groups at 100 meters equals 8" groups at 400 meters(437 yards). Not something I would want to be in front of. It is a battle rifle, not a bench rifle. To me, time is money. So spending time accurizing or attempting to is a waste of $$$. If it is a tinkering project that is fine, don't take it to seriously though. For me an altered 91/30 is not something I want to buy. That is just me. I own Swedes and Swiss surplus rifles for accuracy. My original K31 is the only one left of my Swiss rifles. I paid $129.00 when I bought it years ago. Still have some .10 cent a round GP11 that I bought back then too. I reload 7.62x54r. 180gr Speer RN I believe and 170gr GC cast lead that is great for 1200fps plinking or up to coyote sized varmints at 150 yards. Makes for fun shooting. U.S. ammo uses ball powder. not stick. IMR 4064 works great.