Back when I lived in Georgia, before they "regularized" deer hunting regulations with surrounding states, they briefly had a strange rule for handgun hunting: To be legal, the handgun had to develop 500 ft/lbs of energy at a hundred yards. This pretty much eliminated all but the most powerful .357 magnum handloads, since no factory load in the caliber at the time had that kind of wheaties. It was also silly because the only way it could realistically be enforced would be to have game wardens carrying chronographs in the woods...
Needless to say, that particular regulation didn't last very long.
Within the last ten years, Georgia, Tennessee, and Alabama have adjusted their statutes for allowable hunting firearms until they were all broadly similar, one notable difference being that GA and AL let you hunt Bambi with a .22" or larger centerfire rifle while TN stuck to .24" or larger.
Not so in my new home state of Indiana. Oh, no. No shooting real rifles at deer up here. Hoosier hunters have to use muzzle loaders or shotguns with slugs or "pistol-caliber" carbines...
This all confused me when I got up here. Despite having Illinois on one side and Ohio on the other, Indiana seemed pretty laid-back about guns. Maybe, like any dumb law in Indiana, it had something to do with John Dillinger? But no, I saw the Johnny Depp movie and nowhere in it did he shoot a deer with a centerfire rifle. It turned out that the regulation sprang from a different reason entirely:
Whitetail were actually hunted to extinction in Indiana in the early 20th Century and had to be re-introduced. When they let people hunt them again, they made them do it with one hand tied behind their back to give the deer a chance. Well, as the saying goes, give a deer a chance and he'll take your bumper. Now the deer have spread like hoofed rats and do $40,000,000+ damage to windshields and corn crops in this state EVERY YEAR and we still have to hunt them with one hand tied behind our backs.
No scoped .30-'06s, no old Winchester "thutty-thutties", not so much as a single shot Thompson/Center rifle if it's chambered in an honest-to-O'Connor bottlenecked rifle cartridge suitable for Bambi zapping.
“Pistol caliber” rifles are okay, provided they meet the following criteria:
a) fire a bullet of .357 diameter or larger;
b) have a minimum case length of 1.16 inches; and
c) have a maximum case length of 1.625 inches.
You know where this leads? This leads to crazed young men taking measurements of exotic AR-15 cartridges and thinking strange thoughts, that's where it leads.