If I remember correctly, the 457 has a different spring set up due to the compact size. S&W used a double spring to help with problems with the short barrell length. With that being said, I know my 457 liked hotter loads. It ran flawless with +P ammo, but as with you, it didn't like some weaker loads, especially handloads. You might try a different spring setup and see if it helps any.

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