The only big issue I've ever heard of regarding light .357 ammo was in Smith K-Frame Magnums. Supposedly, the light bullets, being shorter than the heavier bullets, clear the end of the cylinder sooner than the heavier bullets would, allowing unburned/still burning powder to blast the forcing cone, top strap and such, causing extremely accelerated wear, cracked forcing cones and severe flame cutting. Using heavier (and thus, longer) bullets is supposed to take care of much of the problem. When the Magnum K Frames were first designed and sold, there weren't many (maybe not any?) light bullet .357 loads and they were supposedly designed around 158gr loads. The cracked forcing cone problem comes from where S&W milled away part of the bottom of the forcing cone to allow clearance for the crane to close. This thin spot weakens the forcing cone and this is where they tend to split. From everything I have read, the splitting forcing cones tend to be more prevalent on blued guns rather than stainless, although stainless guns can split, too.
Another problem I have read about is the supposed fragility of the K Frame Magnums with steady diets of .357 ammo. Allegedly, they will wear out, go out of time and so on a LOT sooner than larger/stronger .357s with a steady diet of .357 ammo. From what I have read, this is because they were designed for limited amounts of actual .357ammo, with the gun designed for practice with .38 and carry with .357s. When they were designed and marketed, this was common practice. In the mid/late '70s, Police Departments started practicing with their carry loads, which is allegedly when the problems started cropping up.
With light bullets (110gr and 125gr), even with heavier guns, flame cutting is supposedly a common problem. It's really not that big of a problem; from everything I have ever read, flame cutting will progress so far, then stop. Makes the gun look bad but not supposed to progress far enough to compromise structural integrity.
Myself, I've never encountered these problems. I only ever had one K Frame, a well-used (though still delightfully shootable) Mod 66. It was a recreational gun, however, and I only ever shot .38s out of it. The rest of my .357s are larger/heavier/more well designed (4" GP100, 2 1/4" SP101 and a 2 1/8" S&W M649 Magnum Bodyguard) so I don't anticipate any trouble. If you're worried about it, not much you can do other than retire the gun for recreational purposes only, only shoot .38s out of it or reload so that you can tinker with powder/bullet combos to minimize the problems. Those are about the only options. The .357, even in it's modern semi-neutered form, is still a powerful handful for a portable, concealable handgun. Not much you can do about that, it is the nature of the beast. It works well out of well-designed guns but can quickly beat to death lighter guns or those that are poorly designed.
Bub
Howdy another curiosity. I keep reading here and there about 125gr and 110 gr loads being hard on 357s. Has anybody actually destroyed one or seen one destroyed. How long does it take. Years ago I kind of enjoyed shooting 110 gr. at aerosol paint cans. Blow the base out and you have a nice although messy rocket. I never noticed any damage but didn't keep it long before swapping for the next must have gun. Any way just another curious James question. Thanks in advance.
