In the mid-1890s, Colt redesigned the cartridge. They reduced the entire diameter of the bullet to 0.386"OD and lengthened the brass case in order to put both the bullet and its lubrication inside the case. The overall length of both loaded cartridges was about the same. The barrel of the revolver was reduced slightly to match the more popular 38-40 at 0.400"-0.401” groove diameter (this was probably done for manufacturing reasons, not accuracy reasons). This meant that the outside diameter (OD) of the new bullet was smaller than the barrel’s bore, let alone its groove diameter. A hollow-base bullet can be dropped down the bore by gravity alone. The newer soft lead bullet was made with a large hollow base, like Civil War Minié balls. The intent was for the base of the bullet to expand with