I was surfing around YouTube last night and came upon this video. One small segment on the evolution of ammunition reminded me about the ubiquitous .22 LR cartridge, how old it is and how archaic the construction, yet how widely accepted and beloved it is by American gunners.
Designed by the J. Stevens Arms and Tool Co. in 1887, by my math, it has been continuously in production for 131 years. It's a rather archaic cartridge, having both a heeled bullet and rimfire ignition. Estimates of annual production are hard to come by, but most folks agree that US production is more than a billion rounds per year.
Everyone has, (or should have), one good .22. It's invaluable for training, it's a magnificent small game cartridge, and it's actually a lot better at some things than many people give it credit for being. It has been used by militaries worldwide.
If you are not familiar with the .22 cartridge, your education has been sorely neglected.