Here's figures for a Remington with a 5.5 inch barrel. Pyrodex P is usually more potent than Goex black powder, and Swiss black powder can deliver slightly more power than Pyrodex P. The longer R&S barrel can deliver slightly more velocity too.
Gun Barrel Powder by Volume Bullet Weight Average Velocity Calculated Energy Calculated Momentum
.44 Remington, 1858 5.5 inch 28 grains 3F Pyrodex 138 grain, .451 ball 593 ft/s 108 ft-lbs 11.69 ft-s
.44 Remington, 1858 5.5 inch 32 grains 3F Pyrodex 138 grain, .451 ball 700 ft/s 150 ft-lbs 13.80 ft-s
.44 Remington, 1858 5.5 inch 32 grains 3F Pyrodex 140 grain, .454 ball 850 ft/s 224 ft-lbs 17.00 ft-s
.44 Remington, 1858 5.5 inch 35 grains 3F Pyrodex 138 grain, .451 ball 875 ft/s 234 ft-lbs 17.25 ft-s
.44 Remington, 1858 5.5 inch 35 grains 3F Pyrodex 140 grain, .454 ball 945 ft/s 277 ft-lbs 18.90 ft-s
.44 Remington, 1858 5.5 inch 35 grains 3F Pyrodex 143 grain, .457 ball 960 ft/s 292 ft-lbs 19.61 ft-s
.44 Remington, 1858 5.5 inch 37 grains 3F Pyrodex 138 grain, .451 ball 950 ft/s 276 ft-lbs 18.72 ft-s
.44 Remington, 1858 5.5 inch 37 grains 3F Pyrodex 143 grain, .457 ball 960 ft/s 292 ft-lbs 19.61 ft-s
.44 Remington, 1858 5.5 inch 42 grains 3F Pyrodex 143 grain, .457 ball 1019 ft/s 329 ft-lbs 20.81 ft-s
.44 Remington, 1858 5.5 inch 46 grains 3F Pyrodex 143 grain, .457 ball 1050 ft/s 350 ft-lbs 21.45 ft-s
.44 Remington, 1858 5.5 inch 37 grains 3F GEOX Black Powder 140 grain, .454 ball 898 ft/s 250 ft-lbs 17.96 ft-s
.44 Remington, 1858 5.5 inch 40 grains 3F GEOX Black Powder 140 grain, .454 ball 949 ft/s 280 ft-lbs 18.98 ft-s
.44 Remington, 1858 5.5 inch 42 grains 3F GEOX Black Powder 140 grain, .454 ball 964 ft/s 289 ft-lbs 19.28 ft-s
http://www.thehighroad.org/showthread.php?t=674419&page=2
Here's some one shot stop percentages:
Cap and Ball Ballistics
By Ed Sanow
Handguns February 1998
Cap and Ball Wound Ballistics
http://www.thehighroad.org/showthread.php?t=255957&page=2&highlight=sanow
Calibre
Firearm
Bullet
FFFg
Velocity
Energy
1 Shot Stop
.31 Pocket
Baby Dragoon
46gr RB
11gr
821 fps
69 ft lb
30%
.36 Navy
Colt 1851 Navy
70gr RB
22gr
1038 fps
189 ft lb
59%
.44 Army
1861 New Army
141gr RB
35gr
935 fps
274 ft lb
75%
.44 Walker
1847 Walker
141gr RB
60gr
1287 fps
519 ft lb
87%
.44 Calibre RB Ballistics
0.44
1860 Sheriff
141gr RB
30gr
756 fps
179 ft lb
59%
0.44
1861 New Army
141gr RB
35gr
935 fps
274 ft lb
75%
0.44
Ruger Old Army
141gr RB
40gr
1031 fps
333 ft lb
79%
0.44
1848 Dragoon
141gr RB
50gr
1181 fps
437 ft lb
85%
0.44
1847 Walker
141gr RB
60gr
1287 fps
519 ft lb
87%
Cap and Ball versus Modern Cartridges
.31 Pocket
Baby Dragoon
46gr RB
11gr
821 fps
69 ft lb
30%
.22LR
Revolver
37gr LHP
FL
975 fps
78 ft lb
29%
.36 Navy
Colt 1851 Navy
70gr RB
22gr
1038 fps
189 ft lb
59%
9mm S
Semi Auto Pistol
88gr JHP
FL
1000 fps
189 ft lb
59%
.44 Army
New Army
141gr RB
35gr
935 fps
274 ft lb
75%
.44 Spl
Revolver
200gr LHP
FL
810 fps
292 ft lb
73%
.44 Walker
Walker 1847
141gr RB
60gr
1287 fps
519 ft lb
87%
.41 Mag
Revolver
175gr JHP
FL
1250 fps
608 ft lb
89%
Posted by Voodoochile
Ballistics:
Chronograph was placed 10' in front of the muzzle to get these results.
Bullet = .457 143 grain Cast Round Ball.
Powder = Goex FFFg black powder.
Primer = Remington #11
5-1/2” Barrel Average Ballistics.
40gr. Volume = 916 fps. 266 ft. Lbs. 5.5” group @ 20 yards & Violent.
35gr. Volume = 838 fps. 222 ft. Lbs. OK punch with 4” grouping @ 20 yards.
30gr. Volume = 754 fps. 180 ft. Lbs. little recoil with 2.5” grouping @ 20 yards.
25gr. Volume = 667 fps. 141 ft. Lbs. almost not there but with having to use a wad my groups opened up to 3.2" @ 20 yards.
Bullet = .456 220 grain Cast Lee conical bullet.
Powder = Goex FFFg black powder.
Primer = Remington #11
5-1/2” Barrel Average Ballistics.
35gr. Volume = 745 fps. 270 ft. lbs. No room, Violent, & 5” grouping @ 20 yards.
30gr. Volume = 672 fps. 220 ft. lbs. Recoil OK, Decent group of 3” @ 20 yards.
http://www.thehighroad.org/showthread.php?t=387881&highlight=lever