probably not, historicly shotguns are smoothbore if you shoot a slug, THAT would be rifled.
nowhere
Remington now imports the Baikal shotguns under their 'Spartan' brand. Barrels for the "Remington" Spartan SPR-453 are the same as your Baikal.
SORRY, you will never find any because there are none available !
To remove the barrels from a Baikal TOZ-34FP shotgun, first ensure the firearm is unloaded and safe. Then, locate the barrel release lever, usually found on the underside of the action. Press or pull the lever while simultaneously lifting the barrels upward from the receiver. Once the barrels are detached, you can proceed with cleaning or maintenance as needed. Always refer to the manufacturer's manual for specific instructions and safety precautions.
On the Baikal/Remington SPR 310 O/U, you simply push the trigger forward to select the top barrel, leave it alone to have the bottom barrel fire first.
They probably denote what choke the barrel has.
Excelent single barrel shotgun... inexpensive russian made!
Rifle, handgun and shotgun can all have "long" barrels
The cartridges will pop out.
For a Baikal MU21-12, you might have better luck checking with specialized gun shops or online retailers that focus on aftermarket shotgun parts. Websites like GunBroker, ArmsList, or specialized shotgun forums might have listings for barrels or offer advice on where to source them. Additionally, contacting Baikal directly or a gunsmith who specializes in Russian firearms could yield useful information.
I would look at the number of barrels. If there is more than one barrel, you know you have at least a double barrel shotgun. If there are 1 or less barrels, then you don't.
Generally, no. While single shot rifles MAY have the rifle barrel replaced with a shotgun barrel, reverse is not true (usually) A rifle cartridge generates much higher pressures than a shotgun shell.