First, I have found high quality 22 LR ammo like CCI, 'Stingers' to be highly reliable. Second, many countries (America included) arm, or have armed, their assassins with 22 LR pistols; some of which were setup to use low power cartridges! Third, I'm able to rapid fire every shot from a 10 round 22LR magazine inside a 6 inch circle at 10 to 12 yards. I can, also, do the same thing into a 12 inch circle at 25 yards. Finally, if I had to use a 22 LR as a self-defense weapon I'd fire every shot at the target's head. As an aside, all of my 22 LR pistols have, at least, a six inch barrel; but a four or five inch barrel would, still, be fine with me.