I could give you as others have, the Taylor formula, bullet meplat, kinetic energy ad nauseum...The most simple and elegant of explanations as I once read was....
"A 9MM "May" expand, but a .44 will NEVER shrink...."
To add further exclamation to bigger is better.....
The coy and demure lass looked up at the large pistol on the roughneck's belt and excitedly asked "Gee handsome...why do you carry that big ole .45 on your hip...He slowly replied...because they don't make a .46"
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