Originally Posted by Scarecrow
I tend to accept the anecdotal evidence from people who've been shot by .20, .25 and .28 when they say the .25 and .28's hurt more than their lower weight counterparts.
As I said. I think you also have to count in wind resistance and distance to target. You're not firing in a vaccum.
Additionally if you do the math, a gun shooting at 400 fps with a .20gr BB imparts 1.49 joules, where as that same gun at 400fps at .25gr BB imparts 1.86 joules. Let say you shoot that out of the same gun and the FPS drops with the .25gr's to 360fps, the joules is still 1.51. Of course all of these calculations presume you're shooting in a vaccum with no ballistic arc or gravity effect which would influence it further.