The .41 Long Colt Ammo was designed and developed in 1877 in the United States to be used in Colt's double-action Thunderer. The .41 Long Colt Ammo is lengthened version of the .41 Short Colt Ammo. The bullet was lubricated from the outside, and the base of the bullet was small in diameter so that it could fit inside the casing; these bullets are known as a heeled base or heeled bullet. The .22 Rimfire Ammo is the only heeled bullet in the modern market. In the middle of the 1890s, the .41 Long Colt Ammo was redesigned by reducing the entire diameter of the bullet to 0.386 inches. The brass case was increased in length to allow the bullet and lubrication inside the case. The case length of the .41 Long Colt Ammo is 28.9mm, and the bullet diameter of this cartridge is 9.8mm. The .41 Long Colt Ammo came in three different sizes and loads.
The .41 Long Colt Ammo was designed and produced in 1877 by Colt's Manufacturing Company in the United States.
The .41 Long Colt Ammo was initially intended to be used for self-defense in short ranges and provided the shooter with decent accuracy. Today, the .41 Long Colt Ammo is considered a relic of the past, has exhausted its usage and is mainly found with collectors.