https://en.wikipedia.org/wiki/Pattern_1861_Enfield_musketoon
The Pattern 1861 Enfield musketoon was a short-barrel version (610 mm or 24 inches) of the Pattern 1853 Enfield rifled musket, having a faster rifling twist rate (1:48 versus 1:78), along with more rifling grooves (five grooves versus the Pattern 1853's three grooves), which made it as accurate as the rifle at shorter ranges. The much shorter barrel would otherwise reduce the …