Yes- What they all said. It takes time to understand what your needs are then find the right combination of bullet type, weight, velocity. Remember "stopping power" is a relative term to help us compare apples, oranges and bananas!! The formula for energy is weight in grains X velocity squared, divided by 450400 = ft/lbs of energy. As for your 642 I use speer 135 gr gold dot shot barrel in my 638 and titanium, accuracy is "good", expansion was impressive, in my limited testing. The Corbon your using should be fine if it hits to point of aim. Be Safe,

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