Just because the ammo works in another gun, I would not rule it out. Consider buying a box of some other brand standard velocity.


No, I would not ream the chamber either.


Have you looked at the hammer spring? If the gun came to used, perhaps someone fiddled with it and spring is too stiff? Everyone jumps on the recoil spring, but the hammer spring also has an effect on slide operation.


Other than those, I'm running out of ideas that you haven't tried or addressed already.

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So many S&W's, so few funds!!