RBH--
The reason a ".426-432 bullet is a .44" is that the original cartridges were externally lubricated with heeled bullets
like the only surviving member of that clan....the .22 LR. When externally lubricated bullets became a problem (grit, lint)
manufacturers went to inside lubricated bullets, in the same cylinders. So now the bullet is smaller, while the case is
still an actual .44 diameter (or .38 diameter).
Remember, at each step, the folks at the time were solving a particular, current, local problem. They had no long term
goals, didn't know where it would all wind up. It evolved and is odd. But each step made sense in isolation.
So here is the thinking of a guy in about 1866 or so:
I have a .44 Colt 1860 Army, only 3-4 yrs old, but I want cartidges. OK, how to most cheaply do that? Cut the back off the cylinder
and make a rear section with firing pins, and put rimfire cartridges in it....the only kind of cartridges that existed. How
big do I make these new rimfire cartridges.....well, the cylinders are .451-.453, so let's ream them a touch for consistent
diameter and to smooth them up, since inside smoothness was unimportant to a muzzle loader cylinder, to say .460 and
have .457 cartridges. And these .457 soft bullets will fit fine down the barrel which used .451 diameter
round balls. That works, and upgrades my only a few years old expensive revolver to cartridges. A step forward.
And a few years later....people are complaining about grit and stuff sticking to their goopy externally lubed rimfire
bullets. So, some guy says, let's put more of the bullet inside the case with grooves to hold lube. Problem solved.
Oh, the accuracy went all to hell? Hmm. Bullets now too small? OK, we'll step the cylinder to fit these new smaller bullets.
The next problem solved.
And we wind up with "44 caliber (which was really .45)" as .430ish. And .38 caliber, which was really about .375, is
about .357ish. All through the same step by step problem solving. .375 muzzle loading cylinders "cleaned up" to
.385ish, for .380 OD cartridges, originally heeled with .380 bullets, fine for barrels for .375 round balls.
I have examined an old Colt . 38 Colt caliber revolver, and it had straight thru chambers in the cylinder. This, with hollow
based bullets was apparently sort of satisfactory, but within a few years the chambers were stepped to better match a
bullet which fitted inside the case., and barrel diameters reduced, too.
And the resulting drop in bullet diameter due to inside lubrication means that the ".44" (which was really a .45) is dropped
from .457 case OD to a .430ish bullet (.013 ish case wall thickness). The .38s, starting with a .380 case OD, winds up with
.357 ish bullets, leaving about 0.011ish case wall thickness.
And a few years later, in 1873, Colt invented a REAL .45 with normal inside lubed bullets, so the case OD had to be .480 for
a .454 bullet.
And the .44WCF (.44-40) used a very thin necked .443 case OD, and that produced .426 bullets. So they were sort of
following the same rimfire concept that the case OD was the caliber, even when switching to inside lubed bullets
was changing the reality from under that paradigm. Case necks are only about .008, and are easy to crunch in loading.
And the .44 Henry, a Civil War rimfire cartridge, had . 446 bullets and .44 cal external case, heeled bullets. It was following
the rimfire std set by S&W with the first cartridge ever, the .22 RF (now short).
This I have learned because long ago I asked the same question. "Why in the world is a .44 .430 diam and a .38 .357 diam?"
Bill