Biggest Musket Ball found

Found this, what I believe is a Musket Ball. Found on old wagon trail near Santa Fe NM. What would this have been fired from?

Could be artillery cannister shot or a solid lead ball from a shotgun ?

At 1" I’d go for a canister or shrapnel. Depending what date is connected to the battlefield/item.

The English Brown Bess was the largest caliber musket used in any army.

Nominal bore 3/4" firing @ .725-.730" balls (room for paper wad, crud and what not)
@1" is 4 bore and way to big for military sidearms.

I like the canister, shrapnel, suggestions. The shotgun slug, holds water. Didn’t think they made shotguns that big. It was an old wagon trail. Appreciate the help. Think I’ll go back to the same area an have another look. I’m pretty sure the military did use this trail. My other found round balls and slug.

Check out Carl P. Russell’s Guns on the early frontiers (1957). He has a chapter on such things as swivel guns and light artillery employed by civilians and military in the American West, 1815-1845 or so. It appears to me that several of the swivels guns he discusses (some like small cannons, others stocked as enormous shoulder arms) were capable of firing a projectile of the size seen here.