But first a little history lesson in dimensions...... In 1957 during the research into development of a military styled .22 caliber rifle, the Remington .222 Special was created. Due to there being several .222 caliber cartridges under development, the .222 Special was renamed to .223 Remington. The cartridge became the standard for the US Army in 1962 as the M193 Cartridge. Between 1959-63 the increase in US troops in the Vietnam War escalated quickly. Going from around 1000