.357 vs .45acp
honest comparison between the two, fired from the same platform, pros and cons of each.
rather than jump directly to the cartridges performances, lets focus for a moment on your question about how the compare,
fired from the same platform... (and I will assume platform refers to the gun, and not the location where you are shooting
)
First off, there are very few
platforms that can shoot both rounds. The choices of identical guns (same model,...same size, weight, barrel length, etc.) is very small.
Basically you are looking at a large frame DA revolver (S&W N frame), a Single action revolver (Colt SAA, or clone Ruger Blackhawk or new Vaquero) the T/C Contender single shot pistol, and, if you can find one, an LAR Grizzly.
All these guns are, or have been available in both .45acp and .357 Magnum.
And, you want full house loads to compare with, as target loads really don't tell you anything useful. So now we look at cartridge performance. And you must also decide if you accept the "one shot stop" rating concept, and the data supporting it.
But that is a whole different discussion than one about how they feel to shoot, which is what you are asking, right?
Well, in the same platform, what you are looking at is the difference in the feel between the two, and that comes from the energy being launched downrange. Equal and opposite, no getting around that fact. Autoloaders don't really "absorb" any of the recoil energy, they just seem to. And this is because they change the rate of energy transfer, changing the feel of the recoil in our hands, compared to a fixed breech pistol. Autoloaders also add in the weight & momentum of the moving slide to the feel of the recoil. Not to the actual recoil energy, but to the way we feel it.
But either revolver or auto (or single shot) as long as you stay with the same platform, then all you are looking at is what each round does in that platform, and can discout the difference in feel between a revolver and an autoloader.
The .45acp develops 360ish ft/lbs of energy. The hottest loads up this a bit. The .357 delivers over 500 ft/lbs. And remember this is also the energy coming back at you as recoil. Here's an example...
Ruger Blackhawk, shooting with a normal single action grip (allowing the gun to roll in the hand, as opposed to a DA style "locked down" tight grip hold), the .45ACP lifts the barrel 35 to 50 degrees depending on the load (in my hands). The .357 is nearly double that, depending on the load. One could do a scientific comparison with a machine rest removing the shooter variables. I don't have one of those.
For the rest of it, compared to the .45, the .357 is a fire breathing dragon. The much louder report of the magnum is not because of it being supersonic, its supersonic because of the pressure (type and amount of powder being burned) which also results in the louder blast. Also there is something about the .357 bore size at those speeds which produces a stunning report, seems to be worse than a .44 or .45 caliber at the same speeds. Its..sharper, for lack of a better term.
In the same platform, .357 will "kick" harder (somewhere about 25% but everyone feels it differently) and blast louder (NEVER shoot without hearing protection of some kind unless a life hangs in the balance, as far as I'm concerned)
In a full size, reasonably heavy gun the .45acp is mellow, and the full .357 is manageable. In a compact gun the .45 can be managed, but the .357 turns vicious. Not sure what else you want to know, but will give any answers I can.
Oh, yeah, one other thing, the .357 SIG. Its a neat round, but kind of a one trick pony. It was designed to replicate one particular .357mag load, the 125grJHP from a 4" barrel. And this it does, pretty well. However it can't quite match the other, heavier bullet loadings that the .357 Magnum has.