<< The Streetsweeper is a different gun. The one in Max Payne is the Pancor Jackhammer as seen here or here. >>
Yeah. You're right about them being different weapons.
They both are, at heart, the same: automatic weapons that fire shotgun shells. So why the shotgun and jackhammer use different ammo in the game..............I don't know. Again, I guess it's a game device.
I've fired a streetsweeper. Now that I see the jackhammer is different stuff, I want to shoot it too!