It’s happened to all of us at least once. In the middle of a hunt, an enormous wild boar weighing about a hundred kilos takes off in front of you. Having checked he is in your angle of fire, you shoulder your weapon and pull the trigger. The shot fires, but the animal carries on! You are starting to doubt your marksmanship, even though it is well-established along the line of guns. So you fire a second bullet. The black beast continues his flight. “Missed again!” you curse to yourself, thoroughly disheartened.
Today we see rimfire cartridges for small game and target shooting. However, history shows it was the first practical, self-contained ammunition. Based on the old Volcanic rifle’s Rocketball cartridge, which was a caseless design, Horace Smith (Smith & Wesson) conceived a case with a hollow rim (balloon head) that contained the priming compound, fired by an off-set firing pin that crushed the rim. In 1857 he launched it as the 22 Short; and the rest is history!