I've posted parts of this in the past- every year, the count grows. I've shot several hundred thousand rounds of .22LR ammunition: yellow jackets, vipers, stingers, mini-mags, X22-LRPP, X22-LRH, Federal 525 bulk packs. I've had winchesters that weren't lubed and some mini-mags that key-holed, years ago. I've spent years picking up Remington (mostly) ammo that people left on the ground with a primer dent that didn't fire the cartridge- most often from Ruger 10/22 rifles. I wipe them off and put them in boxes, and shoot them for fun, as freebies, at the end of the day. Out of several hundred thousand rounds, I've pulled apart at most a dozen rounds, that failed to fire- out of whatever I was shooting that day, be it a k-22, single six, diamondback, new frontier, marlin 39a, or a single-shot low-wall.
I think if a guy buys junk ammo, the ftf rate goes way higher. You get what you pay for. It helps to shoot the stuff out of a firearm of reasonable quality.