.410 bore

The .410 bore (10.4 mm) is a small caliber shotgun, firing one of the smallest commonly available shotgun shells. A .410 bore shotgun loaded with shot shells is well suited for small game hunting and pest control. The .410 started off in the United Kingdom as a garden gun along with the .360 and the No. 3 bore (9 mm) rimfire, No. 2 bore (7 mm) rimfire, and No. 1 bore (6 mm) rimfire. .410 shells have similar base dimensions to the .45 Colt cartridge, allowing many single-shot firearms, as well as derringers and revolvers chambered in that caliber, to fire .410 shot shells without any modifications. Other small bore shotgun loads include the 9mm Flobert rimfire cartridge, and the less prevalent .22 rimfire shot shell.