That must have been a decimal half-pence, because the pre-decimal ha'penny was the size of a dinner-plate and the reason why the smooth-bore Brown Bess musket persisted well into the era of the rifle. The decimal half-pences were very thin and I remember putting 20 pumps into my Crosman 766 in an effort to fire a steel BB through one of them. It nearly did, then I was struck with horror that I could be tried for treason and deported to Botany Bay for knackering the Queen's Currency and Coppery Fizzog. Because of rampant inflation at the time the Bank of England Police Service looked on currency destruction with one of its blind eyes so I never got to hear a kukkuburra shitting in a eucalyptus bush.