I have told friends for years not to shoot the alloy guns any more then necessary for familiarization due to guns not designed or built for large amounts of shooting that a all steel gun will withstand.

Even steel frame guns in magnum calibers have had problems lasting with steady usage. I got rid of my 642 because of the same reason you mention and went eventually back to a G29 for CCW as much as I hated to make the switch back to the Glock. I always felt under gunned with the 642 and the G29 is in my favorite caliber, 10 mm, and I shoot it much better then the 642 and have twice the rounds in the gun. I do however hate chasing my brass from my automatics when at the range.

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Cranky Old Retired USN Guy