The Mosin Nagant is a simple design that is easy to repair and maintain, but proper technique and an understanding of the design is important. This page will attempt to guide Mosin owners through partial and complete disassembly and provide a pictorial reference of the various parts. For information on which parts will interchange between various models, see the Mosin Nagant Parts Compatibility page.

Tools Quality gunsmithing tools are imperative to prevent damage during firearm disassembly. Anyone who's handled surplus firearms has seen the stripped screw heads, scratched metal and scarred wood. While damage in battle is part of the history of a firearm, damage from poor maintenance techniques is a destruction of that history. Past damage can't be undone, but future damage can be prevented. A good set of hollow ground screwdrivers in various sizes is the most useful tool on the firearm bench. Following that, brass and steel punches and a light hammer are very handy. Forceps for handling small parts and a magnetic bowl for keeping track of them are useful. A well lit, clean work area also helps prevent the loss of small parts. A protective mat on the bench will protect the finish of the firearm and a gun vise can make the job much easier when "three hands" are required. Plastic picks, nylon brushes, paper or cloth towels, swabs and pipe cleaners make detail cleaning easier. A quality cleaning rod and patches will soon be appreciated over the discount variety for periodic maintenance. Types of solvent and opinions on their use are almost as numerous as gun owners and is beyond the scope of this page. Dummy cartridges for checking function, a firing pin protrusion gauge, and a set of headspace gauges round out the well equipped bench.

Exploded Views Below are exploded views of a Soviet M91/30. Other models have variations in the parts which will be covered later. The primary differences are in the stock hardware and sights, especially among the later Finnish models. For larger views, click on the pictures.

Disassembly The following pictures and comments will illustrate the disassembly procedure for the Soviet M91/30.

Depress the barrel band retaining springs and slide the barrel bands forward.

Slide both barrel bands forward past the end of the stock and remove the handguard. The barrel bands will not come off the barrel at this time due to the front sight. Other models may differ in this.
Hold the trigger back and pull the bolt straight to the rear.

Decock the bolt by turning the cocking knob 90 degrees counterclockwise and pull the bolt head and connector bar forward.

Rotate the bolt head 90 degrees clockwise and pull it off the connector bar. Using the large notch on the bolt tool or the connector bar as a wrench, grasp the firing pin between the fingers and unscrew it counterclockwise. Be careful to grasp it firmly as the spring is under pressure.

Remove the magazine tang screw.
Remove the receiver tang screw.

Remove the magazine assembly and receiver assembly from the stock. Some Mosins, especially Finnish, but Russian and Soviet also, have shims at the tang and recoil lug. When removing the action from the stock be careful not to lose the shims and note their location. The trigger pin is held in place only by the stock and if it is loose can fall out upon removal of the action.

Depress the floorplate latch and pull the floorplate away from the magazine body. Compress the follower assembly and pull it straight down from the magazine body.

This completes partial disassembly for routine cleaning and maintenance.
For detailed disassembly, including the magazine and bolt assemblies, continue below.

Unscrew the butt plate.

Drift out the front and rear barrel band springs from the opposite side of the stock with a small blunt nail or punch. A hole for this purpose should be visible. These springs are delicate and can be easily broken if pulled out by the leaf.
Remove the nose cap screw and slide the nose cap forward off the end of the stock. The nose cap screw will thread into the top of the cleaning rod retaining nut and can aid in pulling it out of the stock. Note: Removal of the retaining nut is seldom necessary or worth risking damage to the nose cap screw.
Turn the stock recoil bolt nut counterclockwise with retaining ring pliers or another suitable tool. Carefully drive the recoil bolt out of the stock with a punch. Note: Removal of the recoil bolt is seldom necessary and there is a risk of damaging it.

Remove the floorplate latch screw and pull the floorplate latch straight down out of the magazine body/trigger guard.

Drift out the follower pin and follower carrier pin. The follower carrier spring is screwed to the floorplate. The follower spring can be removed from the follower carrier by lifting up and back.

Drift out the trigger pin and remove the sear/trigger spring screw.

Lift the ejector/interrupter spring and remove the ejector/interrupter from it's slot. Remove the ejector/interrupter spring screw and slide the ejector/interrupter spring forward from the dovetail slot. Note: Early Russian ejector/interrupter were integral with the spring and are removed in one piece just as the spring is removed above.
Drift out the rear sight leaf pin and lift the rear sight leaf spring out of the rear sight base. Remove the rear sight slide from the leaf and pull the buttons and their springs out each side.
Drift out the rear sight base pins and drift the rear sight base forward off of the dovetail.

Drift the front sight off of it's base. The barrel band can now be removed from the barrel. Note: The front sight base is staked to hold the sight in place. It should only be removed if necessary.

Drift the extractor out the back of the bolt head. Note: Removal of the extractor is seldom necessary and there is a risk of damaging it. If it is necessary, a drop of penetrating oil beforehand is recommended.

Reassembly Reassemble the rifle in the reverse order of disassembly taking note of the following:

Screw the firing pin into the cocking knob until the back end is flush with the rear of the cocking knob and the slot lines up with the index mark. After fully assembling the bolt, decock it, make sure the bolt head is tight against the connector bar and check the firing pin protrusion with a gauge. The firing pin should touch the shallower (75) of the two center notches in the gauge and not touch the deeper (95) of the two center notches. If necessary, adjust by screwing the firing pin in or out of the cocking knob, always stopping with the index mark aligned.

A small C-clamp is useful for compressing the rear sight leaf spring. When replacing the front sight be sure to realign the index marks. When replacing the action in the stock tighten the magazine tang screw and receiver tang screw evenly and securely. Loose action screws are a common cause of inaccuracy.

Model Specifics The M91/30 was chosen because it is one of the most common models of the Mosin design and is more similar to all other models than any other model. Below are the exceptions to the above instructions for all other commonly encountered models of Mosins.

Russian M91	The M91 barrel bands are not retained by springs, but are held on by tension. The bands are loosened by turning the screw clockwise as if it were being tightened. The screw is captive to the band and if it is turned too far the wrong way it will break. The front band is removed first, the rear one is loosened to remove the handgaurd and then the rear band is removed. The bands will fit over the front sight to remove them from the barrel.
	The rear sight leaf spring is retained by a screw. The sight base is soldered to the barrel. The rear sight slide is removed from the rear of the slide and can be done with the slide on or off of the rear sight base. Line up the notches on the bottom of the slide with the notches on the bottom of the leaf near the rear.
	Depress the spring cap on one side through the notches with a small punch while depressing the corresponding button. Pull that side of the slide slightly toward the rear of the leaf to prevent the spring cap from reseating. Repeat on the other side and remove the slide.
	The buttons, springs, and spring caps can now be removed from the slide.
Soviet M38	The M38 barrel bands will come off over the front sight globe because it is closer to the end of the barrel. The front sight base is a sleeve held on with a pin. Removal is not recommended.
	The M38 rear sight base is a sleeve held in place by a pin.
Soviet M44 Eastern European M44 Chinese T53 Rear sight same as M38.	The M44/T53 has an attached bayonet that can be removed by taking out the screw. The screw is staked on the opposite end and can be difficult to loosen. The bayonet lug and front sight base are integral and held on by two pins. Removal is not recommended. The barrel bands cannot be removed without removing the bayonet/sight base.
Soviet M91/59 Same as M38.
Soviet M91/38 Rear sight same as M38.	The M91/38 barrel bands will come off just as the M38 bands. The front sight base is often made from a turned down M44 bayonet/sight base and cannot be removed without damage because the rear pin is partially removed in the turning process.
Finnish M91 M24 P-series Same as Russian M91.	Some Finnish long rifle barrel bands are retained by a pin which goes completely through the band and stock. It must be drifted out before removing the band in the same way as the Russian M91. Note: The pin can be delicate and should be removed with care only when necessary.
	Some Finnish long rifle barrel bands are retained by a small wood screw into the stock just forward of the band. It must be removed before removing the band in the same way as the Russian M91.
	Some Finnish long rifles use metal sling hangers in place of the dog collars and they must be removed before removing the rear barrel band. The screw passes through the stock and threads into the opposite side of the hanger. The rear hanger is attached in the same way but is larger.
Finnish M27 Rear sight same as Russian M91.	Some M27s have a sling swivel through the front slot. It must be removed before removing the rear barrel band.
	Some M27s have a rear sling swivel that is held in place by two wood screws.
	The M27 nosecap has a transverse and longitudinal bolt. Remove these to hinge the top of the cap open and slide it forward off the stock. Some nosecaps have extensions to the rear that contain the transverse bolt. The rear barrel band is retained by a transverse bolt.
	The front sight is soldered in place and cannot be removed without heating it.
Finnish M28 Rear sight same as Russian M91. Rear barrel band same as M27. Front sight similar to M27.	The M28 nosecap has a transverse bolt that is removed to slide the nose cap forward off the stock. Some nose caps have a seperate front plate that is attached to the stock by two wood screws. The nosecap will not come off over the front sight.
Finnish M28/30 Rear barrel band same as M27. Nose cap similar to M28.	The M28/30 rear sight base is a sleeve held in place by a retaining screw under the sight leaf and solder.
	The slide is removable from the leaf by removing the leaf from the base. The slide buttons are retained by pins. (M39 sight pictured)
	The M28/30 front sight has a blade that is adjusted with two screws, one on each side. The screws are removed counterclockwise and the blade is lifted from the base. (M39 sight pictured)
Finnish M39 Rear sight similar to M28/30. Front sight similar to M28/30.	The M39 has two set of sling attachment points. The lower rear sling swivel is similar to the the M27. The side rear sling attachement is held in place by two wood screws.
	The M39 barrel band is held in place by a spring similar to the M91/30. It also has a captive vertical bolt on the opposite side to provide tension.
	The M39 nose cap is held in place by a captive vertical bolt and transverse bolt. The top hinges to the left to allow the nosecap to be removed to the bottom of the stock.
Finnish M91/30 Sling hangers same as Finnish M91.	Some Finnish M91/30s have a blade front sight that allows the barrel bands to be removed over it. It also has "stacked" base.