Winchester NATO-Spec Navy Primers 41 are the identical primers Employed in the Lake Metropolis five.56mm ammunition. These primers are created to exacting specifications for shot to shot consistency. All primers are constantly and rigorously examined for regularity and sensitivity at temperatures and circumstances significantly beyond the number of usual usage. Winchester guarantees thoroughly-managed weights of primer mixtures, consistency in measurement and high-quality, precise measurements and tolerances for anvil heights and balance winchester 41 primers in extremes of temperatures and humidity.