There is a discussion on another board as to the legality of 4 Bore shotguns in the US. Since you guy's are the experts, what's the answer? Is the ammo itself legal? Where to get ammo?
http://www.tennesseeguns.com/firearms/shtguns.html

What say you the guru's of the over-bores?

hunting with shot-guns shooting shot larger then 10 guage is illegal. owning one and shooting one isnt (in my state at least). Owning a 4 gauge rifle and hunting with one isnt illegal... the hunting part should be checked by state

smallfry

I think you mean that hunting migratory birds with a shotgun over 10 gauge is illegal.

But hunting jackrabbits with a 4 bore is not illegal.

No sir, My state does not allow you to hunt with a shot-gun shooting shot larger then 10 guage, for any animal. Though this does not include 4,6,8 bore rifles.

What state is that?

I think what SmallFry means is that it is illegal to hunt with a shotgun with a bore larger than 10 guage for any game, but he can hunt game with a rifle that can be any size (2,4,6,8 bore or what ever). It's the difference between what weapon you use, i.e. Shotgun vs. Rifle. This leads into the question: What is a 4 bore gun? a rifle or shotgun. If the bore is fully rifled and it can shoot both shot or lead bullets, what is it? or what about the Paradox guns of old with a partially rifled barrel?

Federal law states that the 10 guage is the larest bore that can be used to hunt migratory birds, many states use this as the standard size for largest bore of shotgun that can be used to hunt any game, however that criterial may not be used when it comes to rifles. To my knowledge I have only have expreience with minimum caliber requirements (no .22 cal for big game, etc.) for rifles)

500grains... arizona.

hsp223... you are correct... I could junt jackrabits with a 4 bore rifle, but not a 4 bore shotgun shooting shot. And just to note... "Bore" designated guns were rifles long before they became shot guns.

Smallfry, You are correct about the use of the 4 bore "shotgun". Here in Missouri, any shotgun larger than a 10 ga. is not legal for any hunting.