Smoothbore muzzleloading fowlers are used quite a lot with lead round balls. Patch them and load them the same as a rifle. Some guys prefer no patch at all and swear by their smoothbore's accuracy.

But I did read the post too quickly. I'm so used to associating .490 balls with .50 calibre weapons I misspoke. The bores measuring .490 would be on a par with a 39 - 40 gauge.