Barnes'' Triple-Shock X Bullet features include all-copper construction, no fragmentation, 28% deeper penetration than lead core bullets, and maximum weight retention. An exclusive feature of the Triple-Shock X Bullet is multiple, precisely engineered rings cut into the bullet shank. These grooved rings act as relief valve as bullet metal flows under pressure while traveling down the bore. Instead of flowing from the front to the base of the bullet, the copper material expands into the grooves. This results in reduced pressures and less copper fouling. Reduced pressures mean the bullet can be safely loaded to higher velocities. The rings also alter barrel harmonics, which can result in improved accuracy.