The .45 Colt (11.43×33mmR), is a rimmed, straight-walled, handgun cartridge dating to 1872. It was originally a black-powder revolver round developed for the Colt Single Action Army revolver. This cartridge was adopted by the U.S. Army in 1873 and served as an official US military handgun cartridge for 14 years.
The .410 bore is one of the smallest caliber of shotgun shell commonly available (along with the 9mm Flobert rimfire cartridge, and the less common .22 rimfire shot shell). A .410 bore shotgun loaded with shot shells is well suited for small game hunting and pest control. The .410 started off in the UK as a garden gun along with the .360 and the No. 3 bore (9mm) rimfire, No. 2 bore (7mm) rimfire, and No. 1 bore (6mm) rimfire. .410 shells have similar base dimensions to the .45 Colt cartridge, allowing many single-shot firearms, as well as some derringers chambered in that caliber, to fire .410 shot shells without any modifications.
