traditions 1858 new army 44 cal revolver

[sandman228]

I own a traditions (pietta) 1858 new army 44 black powder revolver with a howells 45 lc conversion cylinder. ive got litteraly thousands of 45 cal bullets here that I casted for my 1911 45 acp in 200 gr swc 230 lrn and 230 truncated cone . ive been loading the 200 swc and 230 truncated cone bullets in 45 lc and shooting them from this revolver with mixed results. im thinking a heavier bullet would shoot better out of 45 lc so I decided to order the lee 252 .452 swc mold and a .452 sizer . well before I placed the order I decided to slug the bore and was very confused when I measured the slug at .444 ?????? ok I knew the gun was 44 cal and I cast a .454 round ball from pure lead for this gun that shoots great out of it I know in a normal gun .454 would be way to large for 44 cal I just figured it was a little different with black powder ( like a ruger old army taking a .457 bal for 45 cal) . ok how have I been shooting 45 lc with .451-.452 bullets out a .444 barrel ? also I know this conversion cylinder is meant for black powder but I was told by howells it would be ok with smokeless as long as I stayed below 1000 fps . so for pressure issues should I just stick with the lighter bullets?

[Good Cheer]

Just rechecked, slugged a Pietta percussion 1858 with .450 groove diameter. Best reading I could get on the bore diameter was .440. The chamber mouths average .445 with the ones the reamer was run in deeper being a little bit wider.