I came here to point out exactly this: If you only shrink the ball, without reducing its size, well… you’re gonna have problems carrying the ammo.
As a DM, I think I would let them both shrink and reduce the mass, and wait till they fired the weapon before invoking “conservation of momentum” and declaring that the cannon ball drops to the ground after about a meter.
Dunno about 5e etc. but in 1e, which I still play & DM, Enlarge and its reverse affect both the dimensions and mass of an object. So the cannonballs could be reduced to a mass a gun could shoot.
I came here to point out exactly this: If you only shrink the ball, without reducing its size, well… you’re gonna have problems carrying the ammo.
As a DM, I think I would let them both shrink and reduce the mass, and wait till they fired the weapon before invoking “conservation of momentum” and declaring that the cannon ball drops to the ground after about a meter.
Dunno about 5e etc. but in 1e, which I still play & DM, Enlarge and its reverse affect both the dimensions and mass of an object. So the cannonballs could be reduced to a mass a gun could shoot.