If you look at the common 1871 pistol cartridges, the .44 Henry Flat is pretty spunky in comparison. Of the pre-1873 cartridges that proliferated, it was the hottest:
.44 Henry: 200 grain .442" bullet 28 grains powder
.44 American: 205 grain .432" bullet 25 grains powder
.44 Russian: 246 grain .430" bullet 23 grains powder
.44 Colt 210 grain .454 Bullet 21 grains powder
.46 Rimfire* 227 grain .456" bullet 20 grains powder
*also known as .46 French, or .46 short. Used in 5 shot conversions of Remington New Model Army (1858) revolvers.
All of these rounds had reputations a good fight stoppers. By comparison, the Army's .45 Scofield round (1875) had a 230 grain, .454" bullet, with 28-29 grains powder. It barely bested the .44 Henry round.
Posted in Henry board.
The .44 henry flat, with its 28 grains of BP and a 200 grain flat nose bullet, travels from the rifle at 1125 fps (confirmed by my 200 grain, 28 grain BP .45 Schofield .44 Henry Duplication load from my Uberti 1860 Henry). At the muzzle, it is around 575 ft lbs , which is better than the best 40 S&W and about 50-75 ft lbs shy of the standard 175 grain Winchester Silvertip 10mm round. At 100 yards, the .44 henry flat is still traveling about 950-960 fps! This still gives about 425 ft lbs at 100 yards - equal to a good 200 grain .45 ACP loading at the muzzle. No one disparages the 10mm or the .45 ACP!
Then we have the pistols: Smith and Wesson No.3 Americans and Colt 1871 Open Tops. Revolvers give around 800 - 900 fps (based on my 200 grain, 28 grain BP .45 Schofield Henry Duplication load from revolvers). That would give around 350 ft. lbs muzzle energy, the same as standard velocity 9mm or 45 ACP ball. Not too shabby!
Considering the proliferation of the .44 rimfire in the West, it proved itself effective in combat and hunting (as long as you don't get too ambitious!) for 40 or 50 years! With around 200,000 firearms (1860 Henry, 1866 Winchesters, and assorted S&W and Colt revolvers) produced, it certainly saw widespread usage. Was it better than the .44 WCF? Certainly not. It was, however, far more effective than we modern magnum and +P crazy shooters appreciate!