Winchester NATO-Spec Navy Primers 41 are the exact same primers Utilized in the Lake Metropolis five.56mm ammunition. These primers are created to exacting requirements for shot to shot consistency. All primers are constantly and rigorously examined for regularity and sensitivity at temperatures and problems considerably further than the variety of usual use. Winchester guarantees thoroughly-managed weights of primer mixtures, regularity in measurement and top quality, exact measurements and tolerances for anvil heights and balance in winchester 41 primers extremes of temperatures and humidity.