I used .457 round balls in my ROA , they hit so perfectly where I aimed alwasy right at the top edge of the sight at 25 yards that I never tried conicalls , I think placement is much more important when your shooting a marginal gun than a few more foot pounds of energy.

over powder wads prevent chain fire from the front , tight caps on tuned nipples prevent chain fire from the back

you can get a wad cutting punch https://www.trackofthewolf.com/List/Item.aspx/176/1 or I have a guy local that has some you put in a drill press

lubed wads seem to cost much more than they should as much as the ball in some cases , definitely more than my home cast balls did.

I think your right about a marginal gun and placement. Those conicals dont seem to be any more or any less accurate than round balls. They are quite a bit heavier and weight in a slow projectile is definatly advantagious. Think I'll get a mold for them since they seem to shoot good in my rifle also with two patches for a tight fit.

Barrels are Individuals .. a person cannot shoot one load well in a Gun/rifle and assume that is the best for all. My 50cal pistol above shoots the best with that bullet shown. Round balls or powerbelt bp conicals not well.

I dont know what the twist rate is in my pistol but its 1:60 in my rifle I see your pistol is 1:26. Rate of twist determines what shoots good.

5 barrels all same rate of twist. (*might) supposedly/ but cannot be trusted to group a certain load the same. Barrels are only similar.

the ROA with the 1:16 twist actually shot balls very well , but part of it is that they are actually moving rather slow compared to what they would form a rifle.

black powder has a max expansion rate of 2300fps meaning 2000 to 2200 is about all the faster you ever get a projectile moving

cap and and ball your maybe going to make 900-1100 fps so a faster twist helps stabilize rather than over spin.

I really like the LEE 6 cavity molds , they take a bit to get them hot but when they do the bullets you can make for the time you have into them is great. https://www.trackofthewolf.com/Categories/PartDetail.aspx/1198/1/LEE-450-200-6C

I even bought a track of the wolf 6 cavity made by lee .490 round ball mold it is great to be able to sit down an cast for an hour or 90 minutes and have a coffee can of round balls when your done

Same with my Ruger Old Army, I shot both round and conicals, and shot deer with both. Couldn't tell any difference other than using less powder (P Pyrodex (Green Lable)). Both stopped between the ribs and hid on the far side, only tested on two animals so not a very "scientific test" lol.

How far away were they when you shot Okie?