But in the context of this OP, which is the greater threat, an English Bulldog or the Cocker spaniel? Yes, there is a whole host of things more than mass v energy but OP wanted to talk about just these two small parts.
If the discussion were couched in purely theoretical terms, that would make sense. The OP clearly states that the context is "a defensive situation" which makes the discussion practical, not theoretical.
John, of all of my 44 mags, the one I carry is a Smith & Wesson model 69. compared to the duty guns some of us carried it is neither that big or that heavy. It is big enough however, that it allows for full control.
I'm well aware of the S&W model 69 and its weight and size, in fact I owned one for awhile. Nice revolver, but even if I still had it, I wouldn't choose it as either a carry or a nightstand gun. I have other guns that have more than adequate power, a lot more capacity and better shootability.
Capacity is a non issue if have means of rapid reloads available and are a master of your revolver.
There are certainly people who can reload a revolver very rapidly. But no matter how good they are, it's faster to pull the trigger on the next round in the magazine while the revolver master reloads. And when it's time for the revolver master to reload a second time, it's faster to repeat the trigger pull again because the magazine still won't be empty at that point.
Not only that, when I reach for my nightstand gun, there's a good chance I'm not wearing a belt with two reloads on it. Capacity is pretty nice in that situation.
The only situation I personally see where a hi cap 9mm...
I didn't say anything about 9mm. My nightstand gun is a 10mm, for whatever it's worth--not that I would have a problem with replacing it with a 9mm.
The guys that spank me @ 3 yards on multiple targets can't hit the target past 15 yards.
It's a mistake to assume that someone who can shoot fast can't also shoot at distance. Awhile back I took a class where one of the students outshot all the others for speed and accuracy up close. He was also the only student in the class to make a first round hit on a bowling pin set at 50 yards. Coincidentally, he was shooting a 10mm.