SM, ya got me...didn't even think of it until you posted. I just don't think they are worth the money when you can get a nice 1911 in 45ACP and 10mm for the same price.
Yeah, the 10mm has every bit the energy of the .357 with heavier bullets. If you like magnum power and prefer autos, it's the choice.
It is quite hard on 1911 style guns, though. I've seen a heavily used Delta Elite pretty battered up where slide meets frame. Not the best platform for an intensive high pressure caliber like 10 or .357 IMHO. It's designed for the low pressure .45ACP after all.
I've got a .45, good defense caliber, but severely lacking IMHO for an outdoor gun for hiking in bear country or for hunting even though mine has the accuracy. It's a Ruger P90 which started development intended to be over-built for the 10mm. About the time it was about to be introed, they switched it to a .45ACP because 10mm was falling out of favor. Needless to say, a Ruger over-built for a 10 is going to handle anything in .45ACP that won't blow the case.
I just wish Ruger would finish the deal and come out with a P90 in 10mm. I'd get one in a heartbeat!
I'd rather have a magnum revolver on my hip, even .357, to the .45ACP when I'm outdoors, though. But, the 10 IS a magnum for autoloaders. I prefer revolvers for outdoor guns, though. Nothing like a 300 grain .451" bullet out of my blackhawk at 1200 fps to make you feel secure in the field or stop that wounded 350 lb hog at close range.
When I think .45, it's a Colt. I like the caliber even better than .44 magnum. But, then, I do handload. And, when afield with a revolver, you can load your first couple with light loads for rabbits/small game and the rest of the four with fire breathin', but stompin' bear loads. Revolvers tend to be more accurate and stronger than autos and are much more versatile as field guns. I'd rather carry an auto for self defense, though. I'm a LITTLE slow (understatement) with speed loaders and work my reloads better with an auto. But, I do carry revolvers now and then and LOVE the .357 magnum 125 grain JHP load as a man stopper. Neediing to reload is unlikely and I usually carry a back up or two when I carry a big gun IWB.
Yeah, the Coonan is a nice gun, but the 10 will do anything the .357 can do, so if you want a .357 magnum in an auto, just look for a 10 and be happy. Ain't like you're going to be able to practice with .38 special in an auto, after all. That's one of the big advantages to the caliber in a revolver, especially for non-handloaders. Though it headspaces on the rim, I doubt the .38 round would feed reliably in a Coonan due to the short OAL even if you changed recoil springs for the lower pressure.