The Gewehr Patrone 11 (GP11) is a 7.5x55mm Swiss cartridge developed for the Swiss Army. Introduced in 1911, it was a significant advancement in ammunition design and remains highly regarded for its precision and performance.
Key Specifications:
•Bullet Weight: 174 grains (11.3 grams)
•Bullet Type: Full Metal Jacket (FMJ) Boat Tail Spitzer
•Muzzle Velocity: Approximately 2,559 feet per second (780 meters per second)
•Ballistic Coefficient: 0.505 to 0.514
•Effective Range: Up to 800 meters (875 yards) with supersonic speed
•Maximum Range: Between 5,000 and 5,800 meters depending on muzzle velocity and conditions
•Case Material: Brass (with periods of aluminum and steel use during material shortages)
•Propellant: Double-base powder combining nitrocellulose and nitroglycerin
Features and Design:
The GP11 bullet features a lead-antimony core with a jacket made from plated steel or tombac (copper alloy), providing excellent aerodynamic efficiency and ballistic performance. The cartridge cases are typically made from brass, though aluminum and steel were used during wartime shortages.
Usage:
The GP11 cartridge was designed for use in the Schmidt-Rubin series of rifles, such as the Model 1911 and K31. Its design and high manufacturing standards contribute to its reputation for accuracy and reliability, making it popular among collectors and shooters even today.
