Safety

DiskDoctr wrote:
Not sure who picked out 21 ft or why? 20 ft barely takes more than point and shoot. Inside of that, don't even bother with sites.

People have twisted the 21 ft distance thing into something it was never intended. They have heard 21 ft rule but have no idea what it is really about. It's not about being in a safe zone at 21 ft distance. In fact, it's just the opposite. It's a drill to show that even at 21 ft you're not safe from handheld weapons.
Dennis Tueller was a defensive tactics instructor with the Salt Lake City PD years ago. He is the one who developed the 21 ft drill which is named after him in defensive tactics circle. His drill is to show that even if a person is 21 ft away from you they are still a threat with handheld weapons. In cop work you need to get close to a person so you can have some kind of conversation. Cops were thinking that if they expanded the distance that they'd be safe. Someone armed with a knife or club, 21 ft away, seemed like a long distance. Cops were still getting hurt at that distance. What the Tueller Drill demonstrates is if someone is 21 ft away and decides to rush and attack you, that you will not have time to draw and fire before they'll be on you with their weapon.
Even if a person was prepared for the attack and able to get off a shot that at 21 ft the person will still have covered enough distance to be able to inflict serious harm.
That's all the 21 ft drill is. It's to show cops that even at 21 ft distance you're still in the threat zone. It had nothing to do with over 21 ft you're safe. In fact, the drill now has been expanded to 30 ft. It was only intended to show cops that at a distance that seems far away you are still at risk of being harmed by handheld weapons. It's gets twisted by people who don't have a clue what it's about.