The 30-40 Krag is a rifle cartridge developed in the late 19th century, primarily for use in military firearms. It was designed for the Krag-Jørgensen rifle, which was adopted by the United States Army in 1894. The cartridge features a .30 caliber bullet and is known for its moderate recoil and effective range, making it suitable for both military and civilian applications. This cartridge was used during the Spanish-American War and World War I, but it eventually fell out of favor as more powerful and efficient cartridges were developed. Despite this, the 30-40 Krag remains popular among some hunters and collectors today due to its historical significance and unique characteristics.