need 45 cal diameter input

[nekshot]

I got to cleaning these two 410 barrels today. These were intended for sav 170 so there profile is like a rifle. The smallest end of the barrel measures .623 outside, if I drop a .435 round ball in chamber it stops at end of chamber. So if I want to turn these into a 45 cal smoothbore what should I drill these out at? Or do you all have other ideas that would be better than the way I am thinking?
Thanks for input, nekshot

[wgr]

try a .400 round ball

[nekshot]

I am going to have to take out the chokes so if I am drilling I would like to standardize the bore as much as practicle. I have a 44 cal percussion rifle and a 58 rem revolver in 44 so that would be keeping things simple for me but I wanted to do this rifle as a 45 smooth bore.

[KCSO]

With a patched round ball you will need a 470 bore to shoot a 451 round ball. 451 + the thickness of a patch. Same for any other ball size. Remember a smooth bore will load tighter because you have no rifling for the patch to squeeze into. In my smooth bores I sometimes get better accuracy seating a naked bore size ball on a hard card wad. Remember you can't just drill you need to ream and polish too. finish ream taking out about one thousnad or less at a pass and finish with a felt buffer.

[nekshot]

thanks KSCO, thats the info I was looking for. When I was spinning them on the lathe the one is bowed a wee bit, so I get to try straighten my first barrel. Always looking to learn!
nekshot