The loading mechanism of the
spud guns I had as a kid were ingeneous. The
nozzle at the
business end of the gun's barrel was poked into the
tuber to load a
plug o' spud the size of a
Tic Tac.
Compressed air would propel this plug into the ear of one's victim, or, if the attacker was more than a pace away from said victim, the plug would merely slam into the victim's cheek or eyebrow.
Alternative ammunition:
watermelon
Play-Doh
boogers.
Or so I was told by someone who was there.