The Mosin-Nagant Rifle
Field stripping is the term for disassembling a gun into its major components or assemblies. You don't completely disassemble it, but you break it down enough that you can clean and lubricate it. As the term suggests, this is something you might do in the field while further disassembly requiring special tools would be done back at the armory or shop. Let's see how to field strip the historic Mosin-Nagant rifle.
See the dedicated page for lots of details and background on the Mosin-Nagant rifle, properly the Винтовка Мосина, the Vintovka Mosina or "Three-Line" Rifle.
This rifle has been around for a long time, coming from a Tsarist Russian design project that began in 1882.
Sergei Ivanovich Mosin's design was adopted in 1891, hence the designation M1891 Винтовка Мосина, or the Model 1891 Mosin Rifle.
Let's break this down into its major assemblies.
Start, of course, with an empty rifle!
Rotate the bolt upward 90° and retract it to the rear.
Make absolutely certain that the weapon is unloaded.
If there are rounds in the magazine, you can release its floorplate with its catch release. This tends to dump the remaining rounds onto the ground, but it gets them out of the magazine.
Pull the bolt as far back as it will travel.
Pull the trigger, releasing the bolt. Move the bolt slightly forward and then pull it straight back out of the receiver.
To field-strip the bolt, start with it as drawn out of the rear of the receiver, as seen in the first picture.
Holding the cocking piece in your left hand, rotate the bolt handle and main bolt body 90° toward you, as seen in the second picture.
The bolt handle, main bolt body, firing pin and cocking piece can be lifted off the bolt head and firing pin guide bar, as seen in the third picture.
As you can see in in some of these pictures, you will find some rough machining on internal components of some wartime rifles. This rifle was manufactured in 1942 in Izhevsk.
This is probably as much disassembly as needed for routine cleaning. However, you can remove the two screws holding the magazine and trigger guard onto the receiver.
If you are really ambitious, you might try removing the two bands holding the upper handguard and stock on the barrel. For each one, press the retaining latch into the handguard far enough to allow the band to move forward. If you can get both bands to slide completely forward and off the forward handguard, you can remove those stock pieces.
But you may find this more challenging than needed for routine cleaning and maintenance.
Unscrew the cleaning rod and withdraw it from the stock. Your Mosin-Nagant is now fully field stripped and ready for cleaning.