The .36 Navy was used effectively by experts such as Hickock because it had good penetration and the man was insanely accurate with it.
Plus, the use of pure soft lead that seems to deform readily on impact.
Due to burn rates, pressure curves , etc etc There is a velocity limit when using BP, it seems to max out at ~ 900-1000 fps in a handgun
and somewhere between 1800-2000 fps in a rifle.
Thus If one wanted "more" , one needed into increase bullet mass, and that was done by increasing the caliber.
That';s how they ended up with those monster guns, like the 4 Bore African double.
and the .44 and .45 cal pistols.
As our good Coffin has pointed out ( from, gawd help him, actual field experience) what actually works is Big, Slow, Soft, Flatnose bullets.
There was a good reason that the US military went with the .45 ACP: It replicated the ballistics of the .45 Colt in a 5" barrel
The .45 ACP is Big, ~900 fps, only thing missing is soft lead(was not in the spec) and flatnose.
Alloq me to walk our dear readers down the garden path of BP revolvers.... and even if you already know all this crap it's at least entertaining ( to me).
In the Bad Old Days, Colt's Patterson was brought out in a variety of calibers up to .36 . As a repeater it was significant, but the little .28's and .31's
were somewhat anemic, but the .36 was at least effective.
from wikipedia,
snip-------------------------
The Republic of Texas had been the major purchaser of the early Paterson Holster Pistol (No. 5 model), a five shot cal .36 revolver, and Samuel Walker became familiar with it during his service as a Texas Ranger. In 1847, Walker was engaged in the Mexican–American War as a captain in the United States Mounted Rifles. He approached Colt, requesting a large revolver to replace the single-shot Model 1842 Percussion Pistols then in use. The desired .44-.45 caliber revolver would be carried in saddle mounted holsters and would be large enough to dispatch horses as well as enemy soldiers. The Colt Walker was used in the Mexican–American War and on the Texas frontier.[1]
Medical officer John "Rip" Ford took a special interest in the Walkers when they arrived at Veracruz. He obtained two examples for himself and is the primary source for information about their performance during the war and afterward. His observation that the revolver would carry as far and strike with the same or greater force than the .54 caliber Mississippi Rifle seems to have been based on a single observation of a Mexican soldier hit at a distance of well over one hundred yards. The Walker, unlike most succeeding martial pistols and revolvers, was a practical weapon out to about 100 yards.[1]
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Colt had already gone bankrupt the first time when Walker approached him to build what became the Colt Walker .44 Horse pistol weighing in at 4 1⁄2 pounds.
Thus, Colt contracted with Eli Whitney, Jr. at Whitneyville, Connecticut to manufacture these pistols.
With the soft .454 cal RB on top of 60 gr of "the best sporting powder" the Walker was effective out to 100 yards or more, and readily dropped both men and horses.
It was also supplied with a conical bullet, and it may be that using the concial in the iron cylinders led to the walker cylinders blowing up.
The next step was to reduce the cylinder length to accomodate only 50 gr of powder (to prevent blowups) and add a latch to the lever, resulting in the Colt Dragoon.
Even with the shorter barrel and cylinder the Dragoon weighs in at 4 pounds and a few ounces, so all-day belt carry for normal humans is less than comfortable.
As a result the smaller Colt Navy in .36 was brought out and was a hiugh success - but oddly not as succesful (in numbers bought by civialians) as the .31 cal Baby Dragoon. It was not until Colt was able to procure sufficient quantities of the new so-called "Swedish Spring Steel" , produced by the Bessemer process, that he
was able to create the 1860 .44 cal on the same frame as the .36, but with a rebated cylinder. The Swedish steel was far superior to the previously used
"Marshall Iron" that was imported from England and allowed for a stronger, lighter .44 belt revolver. The 1860 holds 30-35 grains of BP , and with a suitable conical can replicate the .45 ACP. Interestingly, due to the nature of BP combustion, by using cartridges with a firm crimp, one gets better performance.
Later, Remington came out with the .46 rimfire cartridge conversion for their Remington New Model Army ( usually referred to as the Model 1858) and later
some wacky fellers over in europe made even larger bore revolvers. Those zany Brits seemed to want .50 and .60 cal revolvers to take tiger hunting I suppose...
So basically, the pattern was established by trial and error - Bigger is Better, and soft Lead was the King except for Dinosaur hunting when penetration mattered more.
But since we are generally playing cowboy games rather than relying upon our sidearms to defend against Mauraiding Maoriau Attacking Morros or Grizzlies,
it is more a topic for discussion than a serious decision.
hope this helps
prof marvel