USFA Peacemakers have fixed firing pins, unlike my 2nd and 3rd generartion Colts
My 18 month old USFA .357's have fixed concave firing pins to cope with the high pressures generated by the magnum cartridge.
All SAAMI ammunition will work fine in USFA's and Colt Peacemakers without ever shaking them loose, as can happen with small frame .357's.
I carried a Nickel 4" S&W #19 every day for over 30 years loaded with Federal .357 125 grain JHP. Now, while I fired several huindred of these and Factory WW 158 grain SWC , I always realized it was basically a .38 Spl that took magnums. If I had fired thousands of these heavy loads it may not be the tight gun it still is today.
In a Colt or USFA the .357 will do no harm, there will be no damage caused to the hand or any other part!
Remember, these are made in the USA of good quality steel and good quality parts (unlike some of the Italian guns)
Duke York
SASS 15978
USFA CSS 199