.357 Magnum history and comparison

Compare the performance of .357 Magnum cartridges with slow-burning powder fired from barrels of various lengths.
https://www.shootingtimes.com/editorial/Popular-357-Magnum-Marches-On-Not-Forgotten/516126

"When it comes to reaching maximum velocities with all available bullet weights, I have found W296 impossible to beat."

"Hornady XTP bullets weighing 110, 125, 140, 158, and 180 grains fit the bill perfectly. ... The five bullets have the same cannelure-to-nose measurement, and they differ only in full-diameter shank length. When loaded to the same overall cartridge length, free travel prior to rifling engagement is the same for those bullets."

"The revolver used for .357 Magnum velocity checks was a Dan Wesson Arms Model 715-VH ... with interchangeable barrels measuring 2.5, 4.0, 6.0, and 8.0 inches."

"A Ruger-made Marlin 1894 lever-action rifle with a barrel measuring 18.125 inches from boltface to muzzle was also used for checking velocities. ... Also serving as a paper-puncher ... was an old, reliable 6.0-inch-barreled Smith & Wesson Model 686 revolver wearing a ... scope in 2-6X magnification."

"Increasing barrel length from 4.0 to 6.0 inches resulted in an average gain of 120 fps (60 fps per inch).
Going from a barrel length of 6.0 inches to 8.0 inches increased average velocity by 119 fps, for virtually the same gain per inch.

Increasing barrel length from 8.0 inches to 18.125 inches resulted in an average gain of 469 fps, or roughly 47 fps per inch of barrel length increase."

"As bullet weight increases, velocity gain in longer barrels decreases ... When going from a 2.5-inch barrel to an 8.0-inch barrel, respective velocity increases for the 110-grain, 125-grain, 140-grain, 158-grain, and 180-grain bullets were 506 fps, 396 fps, 362 fps, 251 fps, and 210 fps. When switching from a 2.5-inch barrel to a barrel measuring 18.125 inches, the 110-grain bullet gained more than twice as much velocity as the 180-grain bullet (1,114 fps versus 519 fps)."

"I also proved to my own satisfaction that from a practical point of view, there is not a lot of difference in accuracy among the five Hornady bullets fired from my guns. Among several factors that could be at work here, all bullets being quite close to the same diameter along with all traveling the same distance prior to engaging the rifling had to be influential."