#20"

The first round up for the Big Freakin’ Cartridge Test is IMI’s take on the Black Hill’s classic heavy precision load, Mk. 262. Branded as “77gr Razor Core”, IMI’s version sports annealed 5.56mm NATO cases, neck and primer sealant, and of course 77gr Open Tip Match projectiles. Based on reputation alone, I expected the best accuracy and relatively high muzzle velocities from this ammunition. The test procedure was as follows:

Through the Modern Calibers series of posts, we’ve covered 40 different rifle and pistol calibers, ranging from the diminutive .22 Winchester Magnum to full power calibers like the 7.62x51mm NATO. The series was intended to give readers a baseline picture of how different calibers compare to each other in performance, but its biggest limitation has been that it is entirely theoretical. The ballistics graphs in that series were created based on numbers spat out by a conventional calculator using nominal muzzle velocity and static ballistic coefficient figures – and while this is accurate enough to give us an idea of the performance of different rounds relative to one another, it is imperfect. Well then, it’s time to get empirical: Introducing the Big Freakin’ Cartridge Test.