400 grain government  bullet,any wad,Old ensford 2fg with Remington  large rifle primers. Get a compression  die to seat the wad so you don't  use the bullet because  it will deform  it and you will have trouble  loading it.
If you just got it off gunbroker,  that's a nice rifle.

I've had better results with the 515 grain 515142 bullet than the standard government 450 grain 515141. Here's what the old Lyman handbook said: 515142. This is a special bullet made for the New York Seventh, Thirteenth, Twenty-second and other New York regiments. Shells are supposed to be crimped over the second band, making the cartridge over all longer, allowing more room for the powder. It is used for long range target work.

Do you know your bore measurements? That would be a good start.

fosjam wrote on Mar 11^th, 2020 at 1:37am:

Groove diameter should be .510.