Indeed that's true. You have less than two seconds to assess the threat and act and it's all over except for the smoke in the air in 10 seconds.
Sometimes folks in forums dwell on the possibility of an active shooter. It's a different situation than self-defense. It's more of an offensive strategy than a defensive one. Taking cover, moving, longer shots, not shooting innocent bystanders... whole 'nuther thing. Not to mention the likelihood of that happening is on par with a plane crash or being hit by lightning.
There's a lot of ballistic gel tests that show how the solid copper or composite bullets perform and the wound cavity they create. It is interesting for sure. As callous as it seems, the bigger the wound, the better. Especially if no vital organs are hit. It takes six minutes for a bad guy to bleed out. That's if a major artery is cut. Hitting the heart, trachea, spine, lungs ... that's disabling. Thus the focus on hitting that 8-inch circle of the center mass. Or the melon. Instant neurological failure. But headshots are far more difficult under duress.
