View Full Version : Mosin-complete disassembly necessary?

October 19, 2011, 05:55 PM
Hi Folks, I'm picking up my first Mosin Nagant tomorrow, and am reading and seeing all of the methods of removing the cosmoline on the web. Trouble is, I want to shoot it this weekend at the range, and won't have time for this complete disassembly. Can I just do the obvious exposed parts, bolt, bore, etc. and then fire it? If not, why not? Not being a wise guy, I just need to understand...

Can I use kerosene or mineral spirits?

As a winter project, I will indeed do the complete disassembly, 'cause I'm going to refinish the stock, & make it very purdy. :D

Thanks for the help!

October 19, 2011, 06:01 PM
What do you mean "Complete disassembly?

You can take the action out of the stock in about two minutes, it is 2 bands and 2 screws.

Pulling the action and wiping everything down should only take a bout a half hour, probably more like 20 min.

October 19, 2011, 06:02 PM
Definately clean the bore and chamber and bolt, the rest can be done later any old gun cleaner will work

October 19, 2011, 08:17 PM
Complete take apart and reassembly should take no more that 15 or 20 mins... Cosmo in the trigger workings may be a bit messy and your trigger pull will be even worse than normal if you don't get it cleaned up... Good luck.

October 19, 2011, 08:53 PM
be careful when loosening the metal bands up front. It's the easiest way to damage the stock. Use some lubrication to slide the bands off and avoid prying it with flathead screwdriver. Otherwise the mosin is one of the easiest to disassemble

May 21, 2012, 09:36 AM
You dont really need to disassemble it at all, they were packed up to be used at a monents notice. But a quick paper-toweling of the chamber and action would be wise if you want to extract casings :D

Te Anau
May 21, 2012, 10:26 AM
Use mineral spirits AND wear nitrile (not latex!!!) gloves.

May 21, 2012, 10:37 AM
well I have recently bought 2 mosin nagants. both had so much cosmoline that neither would fire without being cleaned first. mineral spirits and kerosine are the two most recommended cleaning solvents but I just filled my bathtub up with the hottest water my heater can manage and threw all the metal pieces in with a little dawn and let them sit for a while then I scrubbed them with a greeny weeny. at the minimum you'll have to soak the barrel/reciever to loosen up the cosmoline in the barrel and chamber and if you don't soak the bolt then you stand a chance of your bolt seizing, not to mention depending on the state of the cosmoline you may end up having a bolt that's so slippery you won't be able to cycle it due to your hand slipping off. so if nothing else you need to clean your bolt, barrel, and receiver.

Don P
May 21, 2012, 11:28 AM
Folks I think the OP dated 10/19/2011 has his answer well before now and the responses do him no good being he had plans to shoot that weekend:rolleyes:

May 21, 2012, 11:57 AM
Here is a video of me using 540 foot pound of torque and Kroil to get a Mosin Nagant barrel off the receiver.


May 21, 2012, 05:19 PM
Mineral spirits for the metal and stock...
Brake cleaner works great on the metal parts also, but keep it off the wood stock or it'll damage the finish.

Bolts, I completely disassemble-including removing the extractor- and boil.
Cosmoline is usually caked behind the extractor and cannot be removed without dis-assembly

On a hot sunny day, you can place the stock, wrapped in newspaper, in a black plastic garbage bag on the dash of your car, the cosmo will heat up enough to leach out of the wood.

the rifleer
May 21, 2012, 06:34 PM

What did you need the barrel off for?

May 22, 2012, 11:53 PM

I got some VZ59 Machine gun barrels that were threaded and extractor relieved to fit on Mosin Nagant receivers.

Unfortunately, Tennessee Guns, or who ever they did biz with, did not understand about the variations in clocking of threads from receiver to receiver.

That old receiver in the video that I was pulling the barrel off was the only receiver that would clock with the 4 barrels TG sent me.

It is impossible with 90% of my receivers to get a barrel to headspace and clock with the extractor relief at the same time. Those bore are Chrome lined, and no one wants to loan me a reamer.

Then I slowly experimented with trigger jobs on that rifle, until I found out that most of what people do to improve the trigger is a waste of time.

Here is a video that starts out with many independent variables for the dependent variable, trigger pull force, and then narrows it down to one independent variable.
That is math talk for, "The sear spring is the trigger pull force driver."

the rifleer
May 23, 2012, 12:06 AM
I saw those today. It looks like you bought them all, they were sold out. Have you gotten any to work? is it as accurate as described?

May 23, 2012, 01:39 AM
Like so many things I build, a couple days in the shop, followed by a trip to the range, shoot two groups, go home, write up a report, and I am done.
Range report 7-28-2011

A) M44 with barrel set back one thread, so I could ream out the rust spot in the bottom of the chambers. Perfect bore. Borrowed Dennis' reamer years ago and did this, finally test fired with Preston's stock. Vari X-III 6.5x20x40 boosted by Premier Reticule to 13x40x40, large un cut Limbsaver recoil pad, Boyd's stock pillar bedded and glassed to fit Preston's 91/59, Paul welded the bolt handle, ATI scope mount with third mounting hole drilled and countersunk, 150 gr Hornady 3130 spire soft point .3125" diameter, moly, S&B brass, Rem 9 1/2 primers, 2.950" OAL, trimmed to 2.1", 50 gr Surplus IMR4895 = H322 in Quickload performance and density, 20" barrel, predicts 61.4 kpsi, 2921 fps. 9.5 pounds as tested.
I fired 9 rounds from the big Doggone good bag and rear wedge.

Gun did not group great. At least it stayed on the paper at 50y.
2" 3 shot group at 50y.
Shows no sign of Copper fouling.

B) 1937 Iz Mosin Nagant receiver, VZ59 barrel turned round and an internally stepped sleeve added with Loctite. ATI scope mount with third mounting hole drilled and countersunk. Pillar bedded. .045" shim under rear of sear. Sierra .311" 180 gr Soft point #2310 47 gr Surplus IMR4895 = H322 in Quickload predicts 59.8kpsi 24" barrel 2744 fps
16 pounds as tested.
I fired 8 shots from bi pod in front and mono pod in rear.

Gun groups well. The vertical adjustment in the rear is really nice, but the swaying side to side is not. I need to put an ejector in that rifle.
.5" 3 shot group at 50y
.96" 3 shot group at 100y, there was a 10 minute cease fire between the first two shots and the last shot of this group. During that time I got in a snit with another old geezer [ I could crush him like a bug] over me taking a shot during the 1 minute to cease fire time, and he had his ear protectors off. There were a dozen guys there, including the range master, shaking in fear as the two titans faced off with angry words.
Then my trigger ceased working.
The shim may have got knocked out by the wimpy recoil.
The rear action screw was not accessible at the range, as it is under the scope.
There are 4 lands in the muzzle and two of them show a little Copper.
When I got home, the postman had left my new Timney Mosin Nagant trigger on the doorstep.

May 23, 2012, 04:09 AM
Interesting. Is that a homemade Kydex cheekpiece?

May 23, 2012, 09:55 AM
That is a Karsten's Custom Cheek Rest A-Model.

I put in $250 in parts, $50k in engineering hours, and I get two groups at the range and a rifle worth $100.

It is the tried and true Al Bundy business model.

May 23, 2012, 12:03 PM
Always thought the VZ-59 barrel was a bit overhyped...it's a MG barrel, not a Shilen...
If I were loco enough (and might be someday) to want to re-barrel a MN receiver, I'd get a .308 match blank and find a smith willing to take it on.

I shoot my 91/30 sporter at 600 yards routinely, minute of angle rifle, nothing exceptional by modern standards, but gets the job done.

May 23, 2012, 07:22 PM
Kerosene, mineral spirits and Goo Gone will all dissolve cosmoline. So will boiling hot soapy water.

Mosin-Nagants come in varying degrees of cosmoline saturation. And the cosmoline may or may not be caked. You certainly do want to make certain that your bolt is operating very smoothly. You will probably want to drop out the magazine follower. Whether or not you will need to remove the barrel from the stock is another question. But at some point, you probably should unless you're buying a Mosin (like several of mine) that have actually been shot (and thus cleaned) since WWII.

The bolt is NOT difficult to disassemble. Hopefully, you have the teardrop shaped tool with the "go-no go" gauge for the firing pin.

I have fallen in love with these rifles. They're reliable, fun to shoot, easy to care for, inexpensive to feed, and very intimidating in appearance.

Here is a friend shooting my M44 (gotta love the muzzle flash!!!):