The 224 TTH was introduced by the Texas Trophy Hunters Association in 2000, but it was taken from an old idea that dates back to 1964 when Kenneth Clark of Madera, California developed the original cartridge that was based on the 257 Roberts case necked down to .22cal. He encountered two problems at the time that kept his design from becoming successful. Firstly, there wasn’t any good quality slow burning powder for a 1-in-8 twist barrel that shoots a 75 – 80 grain .22 cal. bullet at 3,600 fps and secondly, not many good quality bullets that could withstand the centrifugal force of traveling at that speed at almost 5,600 revolutions per second. The 224 TTH version is based on the 6mm Remington case, (which is the 257 Roberts case necked down, but with the shoulder changed from 17° to 26°). The 257 Roberts case in turn is based on the old 7×57 Mauser case necked down, making the 224 TTH basically a glorified/improved .22/7×57, which has been in existence in various forms since the early wildcat years. The mousetrap remains the same, the marketing just gets better. The 224 TTH is balistically almost the same as the 223 Winchester Super Short Magnum. See also the 228 Ackley Magnum.