Looked for info on this for some time after seeing it in a Sam Fadala article.

Here's the elusive info on ballistics:

The Harper's Ferry and Springfield Models.
First, the Harper's Ferry:

1982 Black Powder Loading Manual
Projectile: .575", advertised 500-grain, Lyman minie (mould # 575213)
Note: The actual weight was 525 grains, not 500.

30 grains FFg; muzzle velocity 577 fps; 388 ft-lbs muzzle energy
40 grains FFg; muzzle velocity 657 fps; 503 ft-lbs muzzle energy
50 grains FFg; muzzle velocity 730 fps; 621 ft-lbs muzzle energy
60 grains FFg; muzzle velocity 802 fps; 750 ft-lbs muzzle energy

And now the Springfield:

This test was done in the 1860's.

Projectile: Supposed to be 450 grain .5775" Minié, according to government specifications.
Actual weight for this test was 468 grains.

40 grains "Musket Powder", held to be superior to the FFg of the day.

Velocity was recorded to be 603 fps with a ballistic pendulum.

Weight for the Springfield was 3.5 lbs, 5 lbs with stock.


I hope this helps, because I looked for these figures for a long time.