I've heard of one course where the rental rifle was shooting way off target, but don't know which provider put that course on.

But on ammo yes, if you use some which is different from the ammo the gun is zeroed with you will likely get a deviation from the zero.

But the distances for the deer shoot are also not long at all:

100 meters - prone, 3 rounds in a 4 inch round target, and if successful then you move onto:

100 meters - 3 rounds at a deer shaped target(having to hit the heart area),

60 meters - 3 rounds sitting or kneeling

40 meters - 3 rounds standing.