Thank you very much, Mr Davidson, for your posts. Yes, I will now definitely concede about the Henry rifling issue. My barrels indeed have the seven point rifling. You know, I was trying to remember what Ross Seyfried said to use in an old article, it might not even have been DGJ, and you brought it up - Cerosafe! Thank you for the clear directions on how to use this material and how to mic the finished product. You're right, of course, about the tapered barrel, so the "snugness factor" has to be dealt with at the chamber end. I think you're 100% correct about micing the rifling thereabouts.
On a related note, searching the internet I came across a Mike Venturino article about slugging bores. He uses a soft lead roundball and pounds it into the barrel with a wooden hammer and pushes it out with a right-sized dowel(!)
Do you, or anyone here, think there would be any harm in just trying an assortment of commercial .45 rifle bullets just for the heck of it? I know I'd be right lucky if both barrels ended up .458, but it could also be a way to practice paper patching, no?
