The Barnes Triple-Shock X-Bullets in 270 caliber (0.277'') deliver revolutionary performance with 100% copper construction and 150 grain flat base design.Barnes Triple-Shock X-Bullets - 270 Caliber (0.277'')150 grain flat base bullet design100% copper construction for maximum performanceExpands on impact creating four razor-sharp cutting petalsRetains 100% of original weight for deep penetration50 bullets per boxOptimum accuracy when seated 0.03 to 0.07 inches off landsEngineered for hunters who demand one-shot kills these bullets penetrate dense bone and tissue with exceptional reliability making them ideal for big game hunting applications.