It takes the average human something like 1.5 seconds to cover 21'.
How many shots do you think you can get off in that time (keeping in mind that you will most likely have to draw your weapon).
Standing your ground is only going to end up with you being cut. Move dynamically off the line of attack while engaging.
Oooh "moving off the line". Someone here has gotten training! Or read up on it.
Shooting multiple shots in a row accurately is pretty darn hard. If I shot 3 shots in 1.5 seconds, I'd be happy if one hit the target. I'm not a pro though- I have probably only fired a couple thousand rounds.
At that range, you are going to have to aim a shotgun as if it were a rifle. At that range the shot is still in a ball and is being followed closely by the decelerating shot cup or wad, if not still partially inside the cup (although this depends on the cup design).
As for the 21 foot rule, it's true, and nothing new (multiple studies and tests have been done by police agencies, .gov departments, etc.) The average CCW'er would be lucky to at least clear leather (or Kydex) before the guy got there. The smart CCW'er will either be running, or drawing while running away (if their piece is in a position to allow it).
As for "shockwaves", "knockdown power", and the like - oh please. Disregarding range for a moment, only a CNS hit is going to stop someone that quickly, unless the attacker was total psychological ***** and dropped like a box of rocks when the bullet that was prematurely fired while drawing approximately 4.7x faster than ever was done in practice grazes their Skechers.
I have either Rangers, Hydrashoks, Gold Dots, or Starfires in mine.
That's why I carry a semi-auto .45 that was originally designed for officers to stopped drugged up soldiers who would not go down when shot once as my CC... With hollow-points might I add. If I shoot you in the head I wish them luck identifying your body.
I fail to believe that even one or two shots to the attackers center of mass with PDX1 in my mag wouldn't stop them short. Momentum might carry their corpse closer, but while I'm back stepping, It's going to gain me a few extra seconds. Of course this is all in theory, in practice is another thing. Make it 22' and they are fucked!
Honestly though, worst case scenario, some big scary dude is charging me like a bull with a knife in his hand swinging like a mad man, I'm probably going to just turn and run. I'm a pretty quick dude and doubt he could even catch me, but while I run I could have enough time to draw and prepare to turn and empty my mag into his ***.
Who waits for a man armed with a knife to run at you before you draw your weapon? I don't know about you but if I had a gun, and some man with a knife was threatening me I would already have my gun out and aimed at him.
What would you rather have 21 feet out from a guy with a knife? A knife or a gun... I think we would all chose gun.
The key is simple, move off line, and do everything you can to stop the attacker, that includes shooting and grappling with them to prevent them from continually stabbing you if possible
The issue with everyone saying that they're going to keep stabbing you is that not many people are going to stay in an weaver stance and keep trying to shoot while being stabbed. Once you're that close and its clear the attacker is not stopping, perhaps its time for other means. Either try to get a point blank shot in the face/head to destroy the brain, or subdue them by other means (break their arm, hold their arm so they can no longer stab you, grapple them to the ground, throw them off balance away from you so you can get distance, run away, etc.)
Basic human nature is fight or flight. If you're going to fight, dont rely on just a gun.
WHY THE **** ARE YOU STANDING STILL AND GETTING OUT A GUN. RUN THE **** AWAY.
I mean seriously, is it that complicated? You're not a ******* cardboard cutout for christ's sake. I may not be able to draw and take down that gobber with his sword, but I sure as hell can out run the chubby ****. I'm never opposed to running the **** away.
The whole idea of self defense ( I took this form a Tactical Medic Class) it to assess the threat and defuse the situation. If it is beyond defusing retreat, and while retreating reassess the situation and act accordingly with lethal force or less than lethal force. The key is to remove yourself from the environment or remove the threat from the environment by any means you can, in short RUN THE FAWK AWAY!!!
Sorry fellas, but running is a bad idea. You're placing your bets on a guess that you're faster than they are. Personally, I'd rather be stabbed in the front than the back, and be stabbed while fighting the ****** than fleeing in terror.