How strong is a mosin nagant action

[lunicy]

I will tell you right off the bat, I'm a butcher. I'm learning on my own. I learned to use my lathe with nothing more than the internet. Same with my mill.

SO...

I would like to rebarrel and rechamber a rifle or two. More or less, just to get my skills up. If I'm going to mess up a rifle, I want it to be a $70 rifle.:-D

I would not be chambering in magnums, or bmg or nothing silly like that.

How about 45-70

Is this as simple as looking up saami specs and picking cartridges with same/lower pressures than 762x54r?

[Skrenos]

Good luck getting the barrel off.

[500cadillac]

Why not 500 S&W? It will fit the Mosin bolt.

[waksupi]

Lunicy, save yourself some money. Get some cold rolled scrap, and practice your thread cutting, and chambering with that. Use both ends. I assume you have an action you can practice the thread and fit with. No sense burning up barrels on a learning curve. If you have a barrel maker or gun builder anywhere around you, you can probably get barrel stubs for the asking.

[Houndog]

I'll go Waksupi one better! If you have NO turning to diameter, facing to desired length, counterboring or thread cutting experience start with 1 1/8 diameter Delrin or Nylon scrap that can be obtained from a job shop or a metal supplier. One thing I think ALL can agree on is you WILL crash the setup! We all have and do. You will do less damage to your tooling using the two listed materials than you will using Steel. That's what I started with, and I had a VERY GOOD teacher to help me along.

[Bloodman14]

Houndog, +1! Ever seen what happens when you set "0" at the face of the chuck!? Saw it happen; the guy was SERIOUSLY injured.

[Dakoma]

I got a old Mosin with a rotted out bore and would love to rebarrel to 444 Marlin,it has been done before and with little modification other than more bite for the extractor and would be my choice.Just my 2 cent though for a ideal rifle.Let me know when you get good at rebarreling please.;-)

[Bret4207]

As far as strength, we had a member here attempt to blow one up. I forget the specifics, IIRC in the end he ended up warping the action, but it never let go.

[krag35]

I have a friend who had a Nagant that was rechambered to 30/06 by Bannermans I beleive. Didn't shoot worth a hoot. He sold it to a feller who put most of a box of factory 8mm Mauser ammo through it, then sold it off because it "Kicked" to much. I don't know what happened to it after that. I'd say they are tough enough.

[Freightman]

There use to be a thread on GunBoards about a dude who bought the five for 100 deals from CAI and blew them up. He stated that a full case of BE would crack the barrel and receiver but the bolt didn't turn loose. Now you can take that for what it is worth as I would have to see that from behind a cement wall to believe it.

[seppos]

We tested some mosins in gunsmithing school years back.
No ordinary load or even high pressure one blew the action.
Only problem is the relatively open costruction that might blew gasses and metal fragments from the primer towards back if the primer is pierced or the case ruptures.
we chopped couple of mosin actions for short cartridges like 7.62X39.
http://i459.photobucket.com/albums/qq319/seppos_photos/1257781361.jpg
To test the welding we put the regular mosin barrel (7.62X54R) to the action and loaded some cartridges +20-30 % over the max pressure and fired them in the rifles and checked the headspace.. No changes in it despite the fact that the cartridge cases where finished.. text in the cases where almost gone and the primer pocket were loose like barn door..;)
There is some flaws in that old design, but I would never say that the action itself is weak.. On the contrary.. I could say that some of the mauser actions are like timebombs.. among the the model 96:ses there is some that have so hard tempered actions that are like glass.. Little bit of over pressure and they are like granades..
Soft is better.. Soft action greates exess headspace issue, but it does not blow up.. hard tempered action keeps the headspace but turns to antipersonel mine when it eventually brakes up..

[lunicy]

I'll go Waksupi one better! If you have NO turning to diameter, facing to desired length, counterboring or thread cutting experience start with 1 1/8 diameter Delrin or Nylon scrap that can be obtained from a job shop or a metal supplier. One thing I think ALL can agree on is you WILL crash the setup! We all have and do. You will do less damage to your tooling using the two listed materials than you will using Steel. That's what I started with, and I had a VERY GOOD teacher to help me along.

Thanks for the advice. I do know how to face, and thread. I have never done it on a gun. I am by no means an expert. I can thread a steel rod, wanted to make something I can shoot. Mostly for the satisfaction.

Should mock something up with steel rod first though, thanks for the idea.

And yes, we have all crashed the lathe. (and brake the drive gear)

[mike in co]

i have seen pictures of an european 300 win mag done on an mn action....used for long range matches.

so pick a cartridge that i sclose to the bolt amd mag,or go single shot.

i bought a bunch of them for similar projects, but think a match bbl wiht a 7.62x54r match chamber might be fine too.



mike in co

[seppos]

I have even heard rumours of single shot Mosin in caliber .338 Lapua Magnum..;)
Actually when we chopped the mosins the idea was to cut two actions. One from the front and one from back and weld the pieces together.. One mini Mosin and one Magnum one..;)
The distance of the cuts in the action is about an inch or so..

S

[Multigunner]

I have even heard rumours of single shot Mosin in caliber .338 Lapua Magnum..;)
Actually when we chopped the mosins the idea was to cut two actions. One from the front and one from back and weld the pieces together.. One mini Mosin and one Magnum one..;)
The distance of the cuts in the action is about an inch or so..

S
They used to do that with Mausers, mostly cheap 1893 actions that could be had for 20 bucks or less. So long as the welding doesn't heat up the reciever ring the locking recesses aren't affected. Heat sinks and heat stop paste seem to do the job. A friend did a few of the Mausers. He'd counter bore the cut off bolt body and turn the rear section to slide in, then silver braze them together to get a shortened bolt.

The Finns used the Mosin Nagant action for a number of intense wildcats based on the 54R case.

To properly rechamber an MN for the 30-06 the barrel has to be set back 1/4 inch or more, some say 1/2", and then chambered, otherwise the base is too big.
The best of the conversions used a straightened magazine box.

The MN controled feed can be adapted to many cartridges.

Theres a target rifle conversion that re positions the bolt handle to a cut out behind the bridge, to allow low over bore scope mountings or receiver apetures. It looked easy enough.

I never over estimate any near century old rifles. many or most may be as strong as a bank vault but theres always a few that have hidden defects. Wartime manufacture of any design can produce a few bad receivers that passed proof but did so with below the surface damage not easily spotted by inspections with gauges.

Theres also the possibility of a replacement bolt head not being up to par.
I've seen boxes of the boltheads at gunshows, I'm not sure these were ever finished and heat treated much less proofed.

[seppos]

The hardness could be checked.
Idea with Mosins is the possibility to change the boltheads to create the proper headspace.
In armorys they used to have wide assortment of boltheads with different lenghts.
After rebarreling one checks the headspace and swap the right bolthead to create the proper one.
On old days that was much easier and quicker than fitting the barrel according to the headspace.

This same feature with interchangable boltheads makes the Mosin a perfect choise for custom projects. One could have different boltheads for different rim sizes.. For small ones like .22 hornet or .223 one just braze a support ring to the bolt head and replace the old extractor with a proper one. also the ejector slot has to be cut a bit deeper ..
The magazine will most likely be oversized, but one could also modify that quite easily..

S

[Buckshot]

As far as strength, we had a member here attempt to blow one up. I forget the specifics, IIRC in the end he ended up warping the action, but it never let go.

..............Bret, I'm amazed that my "Forgetter" actually remembered, and that would have been Jumptrap. I don't recall if he filled a case with Bullseye or Red Dot, but the action held. Additional details however escape me.

.............Buckshot

[Bret4207]

Yes, Rich, that's who I was referring to. I thought I'd kept a copy of his PM on just when he finally quit and what it did to the rifle, but I must have deleted it.

[littlejack]

Gentlemen, I have "worked up" some pretty healthy loads of IMR 4064 in my sporterized
1952 M44 carbine.
The bore slugs at .313. I shoot .312 jacketed bullets. I load the Hornaday 150 grain sp, And
a rn bullet that looks very much like the Hornaday 303 bullet, but I cannot be certain. I
bought these rn bullets from one of the members of this forum. Both of these bullets shoot
exceptionally well in my rifle. The rifle will shoot the 150 grain sp into 1" any time.
The 174 grain rn will shoot even better than that.
I have Chrony'd the 150 grainers at 2800 fps out of the 20" barrel. This powder charge is 3
grains lighter than the heaviest load I tested. None of the loads had any pressure signs.
The throat in this rifle is long, and I attribute the ability to use heavier powder charges
to that longer throat along with using a .312 bullet in the .313 bore.
I have read that the MN action will indeed withstand the preassures equal to the 30-06
cartridge. With the loads that I shoot in my rifle and am comfortable with, I agree
I do agree that the weak length would be the metalurgy of the action, either bad steel or too
brittle or too soft. The bolthead of the MN has two locking lugs as does the Mauser and all
of the modern Mauser renditions. The bolt also acts as a saftey lug on the right side of the
receiver.
All of this being said, the engineering and general mechanics of the MN action make it quite
strong.
Jack

[JIMinPHX]

If you do get that barrel off, I'd love to see pictures of it. I've never seen one of them apart before & I too would like to rebarrel one some day.

[Gee_Wizz01]

I have also been thinking about a rebarrel to 338 X 54R or possibly the new .338 Marlin. I have the perfect candidate sitting by the work bench, a beautiful 91/30 with a terrible barrel.

G

[ilcop22]

You'd probably have to torch off a MN 91/30 barrel. [smilie=l:

I've had a surplus cartridge blow up in one of my 91/30s without so much as a hiccup. My shoulder felt the difference, but those guns are absolute beasts.

[Suo Gan]

Good luck getting the barrel off.

Thats the truth

[seppos]

Nothing special in Mosins barrel..
Short stump of model 91 barrel from year 1898.
http://i459.photobucket.com/albums/qq319/seppos_photos/mosa.jpg
If I remember right it did not need any heat.. But.. little bit longer wrench..;)

S

[JIMinPHX]

That looks like it has right hand threads. That's a good place to start.

[Frank46]

Some of the mosins have a removable plug that allows one to pump in grease under pressure in theory it makes taking out the bbl easier. Second option is to use a grooving tool and make a groove all the way around the front of the receiver to lessen metallic compression forces between the barrel shoulder and the face of the receiver. I've dismantled two moisins for their actions and did not see the plus. Set up the action and shortened bbl between centers and proceeded to cut the circle all the way around the front of the receiver. Use plenty of lubricating oil and go at least1/4" deep. You should be able to unscrew the bbl with a pipe wrench. Hope this helps someone out. Frank

[MilSurpFan]

Please be sure that you are not cutting up anything collectible. Just because they retail for $80 doesn't mean they are all $80 rifles. I've pulled some valuable stuff out of the piles of supposedly "generic" Mosins. For example, a late 40's 91/30 is worth more than a dozen '42s.

[seppos]

Good point!
I bleeded my heart years back when I had to deactivate a dozen rifles and short weapons to one museum due to the harder gun laws.. They did not had the possibility to buy expensive exebition showcases for the weapons so the only possibility was to make them less dangerous..
Some old Webley revolvers, Japanese Arisakas from Russo Japanese war, like brand new Mosin Nagant presentation rifle with golden bajonet and so on and on..

Do pay attention to the possible history of firearms. Often in this modern world we tend to be short sighted.

S

[jkpq45]

I figure it's time to resurrect this thread--thinking of doing something crazy with my new Winchester M70 barrel in .300 Win Mag. Any outcome for this project?

[3006guns]

I rebarreled a MN to 45-70 some years ago on a Sunday when I was bored. The only lathe I had was a little South Bend 9" and not too much experience, but I got it done. It's a single shot, sitting in a cut down MN stock and you couldn't ask for an uglier duckling. But ya know what>.......?

It shoots!

[paul h]

The real bugger with conversion and the moison is the magazine. If you can live with a single shot, it's a crude but tough action that provides the option to make some interesting customs. But that magazine design is going to be a nightmare to modify and get consistant feeding.

[MBTcustom]

magazine design is going to be a nightmare to modify and get consistant feeding.
That's the bear with any custom conversion. Everything else is relatively "measure and cut" easy, but getting the blessed thing to feed reliably over a range of flat nosed boolit styles and lengths is my personal Waterloo.

[bob208]

a .25 krag. would make a nice varmit rifle even .25-35. a little more steam would be a .40-70 sharps stright. .30-40 is the parent case for it.

[swheeler]

Boolit Master





Join Date: Dec 2007
Location: PRNJ on the shore
Posts: 437 How strong is a mosin nagant action As strong as the brass you are using.

[Frank46]

I believe that the Finns did some sniper/competition rifles in 300 win mag with better stocks.
Cannot recall the model number think it was 85 as the last two numbers. Frank

[Multigunner]

I believe that the Finns did some sniper/competition rifles in 300 win mag with better stocks.
Cannot recall the model number think it was 85 as the last two numbers. Frank

That interested me, so I did a little googling. I haven't found much on it so far except someone mentioned seeing one used at a competition in Finland in 2006.

We should remember that the Finns have been modifying and rebarreling these rifles for generations so they know exactly what to look for when choosing an action for conversion, and have access to all the most modern diagnostic equipment for checking old actions for cracks or inclusions.

The MN is an old favorite there and has been the basis of a great many fine sporters and target rifles, in a number of wild cat and standard chamberings.

PS
Should one decide to rechamber one of these while using the original barrel, remember that sufficient neck clearance is a must if using oversized Boolits or J-words suited to the 7.62 Russian bore.
There are some Finn barrels that are much closer to our standards for a .30 barrel than the older Soviet barrels, so those would work best with any '06 or other .30 conversions.

Seems to me that a 7.62 NATO or .308 conversion would work out a lot better than a .30-06 conversion. The breech would still need to be set back, but the chamber would not be cut as deeply, leaving more meat to the reinforce at the front of the chamber.

[Frank46]

From what I gather the Finns prefer the older hex style actions. Maybe they know something we don't?. Frank

[Buckshot]

From what I gather the Finns prefer the older hex style actions. Maybe they know something we don't?. Frank

.............I think it may be that they used both (Hex and round) but the hex actions predominate due to the early years they accumilated so many of them.

...............Buckshot

[Hardcast416taylor]

I have seen examples of M/N`s rebarreled to wildcat cartridges on the 54R case. The larger dia. wildcats had a window cut out on the magazine on each side to allow the bigger dia. rounds to feed. The relief cutting on the barrel to allow easier removal is very sound advice.Robert

[Clark]

I worked up loads with the 7.62x54R cartridge until the bolt jammed.
It is a very strong action.
I don't think anything is hardened but the springs.

I converted one to 45/70 ~8 years ago.
Converting a Mauser to magnum requires opening up the hardened bolt face with carbide.
But I could grind a custom tool out of high speed steel to open the Mosin Nagant bolt face for 45/70.

I have had Mosin Nagants require over 500 foot pounds of torque to get the barrel off. It takes 200 to get the same barrel, when cleaned, back on.
That means they put them on with 200 foot pounds of torque, and then it rusted for 70 years.

All the MN receivers clock differently.
The extractor relief cut needs to be almost 180 degrees to clear the 90 degrees of extractor rotation plus two extractor widths.
But you want more than 180 degrees rim contact with the barrel to stand up to the firing pin and still get accuracy.
This all means the gunsmithing has to be done right.
Cut threads -> torque -> mark -> extractor relief cut -> finish chambering

http://i757.photobucket.com/albums/xx220/ClarkM/91-30extractorRelief-1.jpg
http://i757.photobucket.com/albums/xx220/ClarkM/452-70ExtratorRelief.jpg
http://i757.photobucket.com/albums/xx220/ClarkM/452-70ExtractorRelief45Degrees.jpg