[Doe Eyes]

I doubt it would be able to accurately fire continuously for a full minute, but thats just me.

You're right. It only hold 120 rounds.

[sukhoi-30mki]

That’s only the number of rounds in ready-to-fire state.

It can carry several times more in it’s mounting. Which is what almost all naval guns do.

http://www.navweaps.com/Weapons/WNSweden_57-70_mk123.htm