.45-70 Government (1873 Trapdoor) using Sierra bullets
Date: Feb 14 2018
As its name implies, the .45-70 Government (aka .45-70) started life as a military round in the U.S. Model 1873 Springfield rifle, but due to the rifle’s rather unique breech mechanism, it is better known as the “Trapdoor.” The cartridge quickly became popular among civilians in a variety of single-shot and lever-action rifles, such as the Marlin Model 1895 and Winchester Model 1886. It was originally a black-powder round, but as smokeless powders appeared, factories made the switch and offered both types for many years. Today, only smokeless-powder loads are offered by major ammunition companies. The current industry pressure guideline is established at 28,000 CUP; however, factory-load pressures are notably less than this figure. Federal Cartridge, Remington and Winchester advertise a 300-grain jacketed bullet at velocities between 1,810 to 1,880 fps, while Remington still offers the proven 405-grain JSP bullet 1,330 fps.
The accompanying data utilizing the Sierra 300-grain hollowpoint bullet was developed specifically for U.S. 1873 Springfield rifles in good working condition. As a word of caution: These are antique rifles constructed of comparatively soft metal. Many have seen considerable use– even abuse– during the frontier era and are not in safe firing condition. If in doubt about your rifle, contact a professional that is familiar with these rifles and their actions to be certain your rifle is in safe, operable condition before firing.
The accompanying data is very low pressure, with maximum loads developing less pressure than industry standards or even factory loads. As a result, “maximum” listed powder charges were categorically more accurate than listed “starting” loads.