What is origin of the idiom shoot the wad?

Answer 1

In some current American slang it is a reference to male ejaculation; however the phrase has a very long history covering most of the time that muskets have been in use up to the present. The wad is a piece of paper put in the muzzle along with the projectile and gun powder. If the shooter is too hasty -- say in a tense battle -- they may not include the projectile. The result is a fire without the intended bullet; only the wad will fly out...a wasted shot. Hence, "shooting your wad" can mean expending your energy fruitlessly. The OED also references the wad as in a roll of paper money; in this case "shooting your wad" means blowing all your cash at once.