With high precision and long-range shooting, sniper rifles have won a place on the battlefield by delivering a fatal blow to the enemy. In the precise construction of sniper rifles, barrel technology is the key to determining their accuracy and range. Since the birth of sniper rifles, barrel technology has undergone a long period of development. The innovation of materials, refinement of processes, and optimization of rifling design outline the century long evolution of gun barrel technology. In the early days, the material of sniper rifle barrels was average, and they were prone to wear and tear after continuous firing, resulting in low accuracy. Every time dozens of bullets are fired, snipers have to use special tools to clean the gun barrel. At the end of the 18th century, iron gun barrels were applied and their durability was improved. However, due to the forging process, the inner wall of the barrel is rough, the accuracy of rifling processing is low, and the continuity of shooting is still difficult to guarantee. In the mid-19th century, the long-range sniper rifle designed by British firearms designer Joseph Whitworth brought technological breakthroughs. This rifle adopts a unique hexagonal rifling, which makes the bullet rotation more stable and the shooting accuracy higher. During the same period, the German Mauser company adopted cold forging technology to process rifling, making the metal structure of the gun barrel more precise and the gun barrel life longer, laying the foundation for mass production. At the beginning of the 20th century, gun barrel technology continued to be optimized and upgraded. During World War II, the Soviet Union constructed an efficient sniper system by rigorously screening the high-precision barrel of the Mosin Nagan rifle and pairing it with a scope. After World War II, gun barrels made of advanced steel materials had significantly improved lifespan due to their excellent corrosion resistance and thermal stability. The free floating barrel design has become standard, with the barrel only connected to the receiver, enhancing shooting stability. In the early stages of the Vietnam War, the American M40 sniper rifle's shooting accuracy was affected by the deformation of its wooden stock due to moisture. Later, it was replaced with a fiberglass stock and a free floating barrel, which significantly improved its performance. Entering the 21st century, CNC machining technology has achieved new heights in gun barrel manufacturing accuracy, with tolerances controlled at the sub micron level; Titanium nitride and other coating technologies reduce inner wall wear, decrease bullet offset during continuous shooting, and ensure long-term shooting stability. In addition, to meet the demand for ultra long range, some sniper rifles adopt an ultra long rifling design, which extends the acceleration time of the bullet in the barrel, improves the initial velocity and ballistic stability. The M200 sniper rifle, with its polygonal rifling and free floating barrel design, has an effective range of 1500 meters and has become a model for modern sniper rifle long-range precision shooting. The evolution of sniper rifle barrels indicates that in the field of military equipment, improving accuracy depends on breakthroughs in basic materials and innovative manufacturing processes. From the initial bronze tube to modern high-performance gun barrels, this development trajectory not only reflects military technological progress, but also embodies the relentless pursuit of precision by firearm designers. (New Society)