Always use the correct ammunition for your firearm as marked by the manufacturer.
That said, we hear rumors the Mosin-Nagant rifle can shoot the .30-30 Winchester cartridge in an emergency.
These guys test out the dangerous rumor for us, so we can save our bodies and guns from potential destruction.
If the zombie apocalypse happens and you are all out of ammo for your Mosin-Nagant rifle, what do you do? Maybe you find a box of Winchester .30-30 cartridges in an old hunter's cabin and figure they might work.
Well, your Mosin-Nagant has a larger chamber than the .30-30 cartridge. Will it work anyway?
As demonstrated in the video, the answer is a big, fat no.
The idea is too dangerous to be truly useful, because the cartridge case can rupture. You better just stock up on the correct ammunition. You'll stay safe, and your Mosin-Nagant will continue to work properly for years.