"...if S&W knows how to build a stronger K-frame why didn't they do it back then?"
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Making new frame forging dies and machine tooling for a new size frame costs lots of those $'s. S&W did a very good job with the K-frame .357's and they worked fine with the ammo of that time; what threw egg in the fan was the advent of super hot, light bullet .357 ammo that caused cracking of the cone (not the frame). The initial idea was to provide a gun that was light to carry but capable of occasional firing of .357 loads, without having to do a major rework of the revolver line. But John Q. Public demanded light guns that could handle heavy loads. Sort of like wanting a sports car that can carry ten tons of coal, but then who said Mr. Public has ever been reasonable.
Jim
$
Making new frame forging dies and machine tooling for a new size frame costs lots of those $'s. S&W did a very good job with the K-frame .357's and they worked fine with the ammo of that time; what threw egg in the fan was the advent of super hot, light bullet .357 ammo that caused cracking of the cone (not the frame). The initial idea was to provide a gun that was light to carry but capable of occasional firing of .357 loads, without having to do a major rework of the revolver line. But John Q. Public demanded light guns that could handle heavy loads. Sort of like wanting a sports car that can carry ten tons of coal, but then who said Mr. Public has ever been reasonable.
Jim