[Bezoar]

Ive read over the ears about some guns chambered in say, 357 magnum, that the manufacturer says "only shoot full power 357 loads in occaissionally" and youll be fine.

But what i am wondering is, if a gun is chambered for a specific caliber, why isnt it safe to use the most powerful loading of that caliber in that handgun?

[GRIZ22]

I've never seen a manufacturer state what you say but it depends on the gun.

If you're shooting a N or L frame S&W or a GP100 those guns can take all the 357 you can put through it. A K or J frame size gun being smaller won't stand a lon term battering with full magnums all the time. Timing will go, forcing cones split, and frames will stretch. You are just putting higher stresses on smaller parts which will wear faster. The larger frame guns will also wear faster but much more slowly than the small frame ones. Safe in either size, wear is the issue.

There are design limits built into every mechanical contraption. Drive your Hyundai at 100 mph all the time and you'll pay for engines more often. No problem for your Porsche as that was designed to do 100 all day long.

[ZeSpectre]

edit - Grizz beat me to it.

[Myself]

There are also guns that date back to the black powder loads and much lower pressure levels than can be obtained today. A classic example is the Colt .45 SAA. If you try to fire a modern max load .45 Colt round in that gun you may blow it up.

[Bezoar]

say i go out and by a generic brand x revolver in 357, and then go buy a box of those "180-200 grain" 357 magnum loads for deer hunting, and then read a small print paragraph on the barrel saying "nothing over 158 grains please".

i mean more like the following:

"yeah joe, i use those 180 gr 357 because im using a 357 for deer adn they shoot GREAT"
instead of

"yeah joe, i know i have a brand new stainless steel 357, but i have to use 38 special loads to keep from blowing it up"