Yeah, raw ballistic power is just a ballpark number, usually thrown around in "all other things being equal" discussions. Shot placement and other factors absol

Yeah, raw ballistic power is just a ballpark number, usually thrown around in "all other things being equal" discussions. Shot placement and other factors absolutely matter as much, or more, when it comes to choosing what firearm to carry for a given situation. But there is usually a "floor" to the amount of ballistic power you want, based on empirical observations over time. Eg, people have noticed that .22LR doesn't tend to work very well for bear defense, so they prefer a larger cartridge, etc. Note too that there are other factors (penetration depth, projectile expansion / fragmentation, etc) that come into play. And with many of those things, there's a lot of folklore around, some science which may or may not carry over (for example, the question of how projectiles fragment in ballistic gel, versus in actual flesh), and no small amount of controversy and debate. If you want to amuse yourself sometime, find a couple of friends who are avid shooters and ask them "which round is the best round for self-defense, vis-a-vis stopping power?" Most likely they'll still be arguing about it 2 or 3 hours later when you quietly slip away to go do something else...