Mosin-Nagant accuracy - a start

Is the 20-22 inches that was mentioned the optimal length for the 54r cartridge as far as velocity goes? Or is that the best length to stiffen up a 91/30 barrel?

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^^
Longer barrel length would increase velocity (to a point).
Shortening the very light contour barrel (it's still only about 5/8" at 22") increases its stiffness and reduces barrel "whip".
For most, the slight loss in velocity is far outweighed by better barrel harmonics.
 
Oh ok, seems I remember reading that a cartridge is only gonna produce so much velocity out to a certain length. I see what you're saying now.

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Can't recall the figures, but there wasn't much of a velocity loss at all when I had one of mine cut back to 22 inches.
Denis
 
Good to know thanks Denis, I've always had the urge to do up a Mosin. I have a couple M39's too, maybe I'll do the Sako. I say this while ducking to avoid any flying objects while mentioning such a thing. [emoji2]

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My 22-inch "full custom" sits in a pillar-bedded Boyds stock with Rock Solid scope mount & extended bolt, under a Leupold scope, with a slightly-tweaked military trigger.

My cheap custom retains full barrel length, uses a Boyds stock (no bedding), Smith front sight, otherwise unmodified barreled action, military rear sight.

Looked up some figures.

Standard mil barrel length, "cheap sporter" chrono:
Win 180 JSP 2553 FPS
Horn 174 BTHP 2646 FPS
Surplus 147 2790 FPS

Accuracy:
Win 1 1/8 Ins
Horn 1 5/8 Ins
Surplus 3/4 Ins

22-inch "full-sporter" chrono:
Win 180 JSP 2641 FPS
Horn 174 2696 FPS
Surplus not chronoed.

Accuracy:
Win 180 1 3/8 Ins
Horn 174 3/4 Ins
Surplus 147 1 11/16 Ins

Chrono with one 5-shot string each load at 15 feet, accuracy best 5-shot group among three 5-shot test strings at 100 yards off rest.

The sniper has not been chronoed, but in original military configuration with Russian optic & no modifications at all after the Soviet refurb:
Win 2 1/8 Ins
Horn 1 5/16 Ins
Surplus 1 7/8 Ins.

Denis
 
Individual rifles & bore conditions will obviously affect the results, but judging from my limited sampling I'd say you won't lose anything in either accuracy or velocity by cutting back to something like 22 inches.

I wouldn't go shorter in the caliber.
Denis
 
OK, I cut the barrel down 5". Following Larry Potterfield's video, I went looking for a hardened dovetail guide, but the one he used is no longer made. I found one from Dixie Gun Works, but it turns out it is not really square on the ends, not much of a help to make a square cut. That's OK; I do cut dovetails now and then. So, I did my best (not bad) with hacksaw and file. I bought Brownell's 11 degree crown cutter and a "303" brass bore guide. Two reviews on their site: one says "perfect for Mosin", the other "too big". I'll go with too big, but a little emery cloth and a drill press fixed that. Brownell's also sells a handle, but it's aluminum. I simply tightened two 1/4-20 nuts on their threads and used a small ratchet drive to rotate the tool. Tested it before I cut the barrel, and I found that I had to reduce the pilot diameter a little more after cutting. Lands were more worn near the muzzle. The crown tool worked great. Finished with some emery cloth by hand. See my photo.

Got to the range today, and first thing I found is my POI is a foot higher than before cutting. I'll have to adjust the scope mount. I did shoot one group with a warm barrel and not taking my time really. See the photo. I should have checked the spotting scope each shot, but I didn't, so I don't know the order. I would like to think the 3 are my group, and the other two to the right are the barrel getting hot, but I am going to rework my loads first.

Velocity - here are the before/after results:

150 Sierra ProHunter (0.311) 52 gr H380
2,760/2,659 Std 7.0/18.5

Wolf commercial 180
2,619/2,552 Std 53/11.4

Haven't done a thing with the stock. I'm off to rework some loads.
 

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Mosins ... accuracy? LOL
Click to expand...

Before you laugh too loud, take in some CMP Vintage Rifle Matches. If a guy would take the time to learn to shoot the Mosin, they can be quite accurate.

I'm a CMP Master Instructor, I conduct GSM Clinics and Matches. One old boy went out the night before one such match, bought a Mosin and some surplus ammo, showed up the next morning to win the match the first time he shot the rifle.

Its not a Springfield '03, but it doesn't shoot in the Springfield Matches, its fired in the Military or other vintage military rifles and like I said, if a person takes the time to learn to shoot the Mosin, they will shoot.
 
I have 2 of them. Both have minty bores and both will shoot VERY well with good ammo.
Most imported surplus ammo is capable of about 3 MOA and some is a bit better, but much can be a lot worse.

But with PPU ammo or with my handloads and Sierra bullets, it's common for me to shoot a ragged hole with 5 rounds with either one at 50 yards. At 100 yards I can keep them slightely under 2 MOA and I bet they will do better, but that's all I can do at my age and with my eyes. And that only on good days.

I have made a few sporters on Mosins and re-barreled them with Green Mountain Barrels, installed Timney triggers and put side mounts on them for scopes. Those rifles shoot as well as any other rifle. Sub MOA is common.

So the action is for locking the bolt against the shell head and for feeding rounds. If the shooter does his job right, a Mosin Nagant with a good barrel can shoot as well as a Remington 700 given the same quality of barrel and the same quality of ammo.

Most bad news we hear about the inaccuracy of M/N rifles is because of bad bores on 70-90 year old guns that have not been taken good care of, coupled with so-so ammo. No rifle is more accurate than it's ammo and if Accuracy International Rifles or Remington 40XBs or the best Tikkas were allowed to rust and were given bad ammo I bet you'd find they would shoot badly too.

I would not rate the M/N rifles at the same level as the 96 Swede, the 1903 Springfield or the best grade of AR-15s, but that is NOT to say they are bad rifles. They shoot better than 99.5% of men can hold them if they have a good bore and if you give them good ammo.

3MOA may seem boring to many readers here, but I challenge all to go out and run 20 rounds from any rifle they own with any ammo they have at 100 yards and use NO artificial rest and see if you can shoot 3MOA. YOU! Not your rifle. Not your ammo. Not your scope.
YOU!
Prone, sitting kneeling standing or anything else. If you fail to keep all 20 round into a 3" circle then go fire another 20 using a pack or even a by-pod and see how you do, but NO bench and no truck hood or anything that may be called a mack-shift bench.

DO NOT feel insulted and DO NOT feel embarrassed. Do it and learn. That's how you will become a better marksman, but first admitting to yourself that you have room to improve.
The only man that can't get better is one that thinks he's perfect. If you are not god, you are not perfect! If you are god you don't need my advise and lightning bolts are more effective anyway.

So go try it and see what the real truth is, and then practice your shooting from the positions you are worst at. That's the only way you will get better.

If shooters are purely honest most will find that a 3 MOA rifle is better than they are.
 
To add to what Wyosmith posted, The X-10 Ring on the target used in the CMP vintage rifle matches, is 3.5 inches.

All the talk about sub min military rifles, you seldom see cleaned targets. You shoot prone unsupported except for the sling, setting w/sling and standing.

3 minute rifles ARENT when you add the shooter.

I get a kick out of those who talk about their constant MOA vintage rifles, I've shot enough CMP GSM matches to know that isn't gonna happen.

Granted some rifles are easier to shoot then others. For example I shoot the M1903A3 and M1917. Both are capable rifles, the difference is my 'A3 is as smooth as glass, the M1917 with its "cock on closing" bolt turns out to be a wrestling match in Rapid Fire.

None of my rifles shoot worth a poop in the off hand (standing) position.
 
When you cut the barrel, the muzzle is at a different point in space when the bullet exits the muzzle as the barrel "whips" (harmonics) due to both length and the now, stiffer barrel.
Hence, your change in p.o.i.
 
Oh wow no velocity loss at all a[n]d even picked up some.
Click to expand...
Every barrel is an island.
There is no other like it.

I chopped a .444 Marlin from 22" to 19" and lost absolutely nothing.
Another guy chopped from 22" to 18", just a few weeks later, and lost nearly 200 fps.

Every barrel is an island...
 
Hence my comment about individual rifles & bores. :)
You never know till you know.

Latitude sometimes matters, too.
I have a Browning Hi-Power that shoots faster up in Idaho than it does down here in Utah.
I THINK it's the proximity to the equator, but that theory remains unproven.
Denis
 
Latitude sometimes matters, too.
I have a Browning Hi-Power that shoots faster up in Idaho than it does down here in Utah.
I THINK it's the proximity to the equator, but that theory remains unproven.
Click to expand...
...Not the equator.
It's the extra freedom!
 
It might have more to do with altitude because there is less gravity at the equator than at higher latitudes. There is also less gravity at higher altitudes but there is also less air. If you want a really flat shooting rifle shoot it in outer space. Near zero gravity and near zero atmosphere and that bullet will fly "forever".
 
Accuracy up there is vulnerable to orbiting space debris, gravitational pull by nearby planetary bodies, cometary interference, and the black hole suck-factor.

There is no free lunch. :)
Denis
 
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