RE: Best shotgun load for rabbits?
Like others have said, you want to use a good cheap low brass number 6 shot.
But that also depends on what choke you use and what part of the country you live in and what season you are hunting in.
The purpose of the low brass shot shells is that they expand their shot patternquicker than a high power shell. They cost less - which means you can shoot more for the same amount of money. Plus a rabbit is not dangerous game that has to be killed on the first shot.
Early fall, your shots will be close, because there is still foliage on the trees and the brush.
After Christmas, when the snow and the frosts has killed most of the vegetation - you have to go to a modified or full choke and a little better shell because the rabbits will see you sooner and your shots might not be as close - depending on what part of the country you live in.
I use the Remington Dove and Quail loads in the early fall and the Duck and Pheasant loads after Christmas - during our second season.
But I always carry some Duck and Pheasant loads, because you never know when you might run into some Pheasants.
I also carry some Turkey loads in the fall when Turkeys are in season.