Winchester NATO-Spec Navy Primers forty one are the identical primers Employed in the Lake Town 5.56mm ammunition. These primers are developed to exacting requirements for shot to shot regularity. All primers are constantly and rigorously tested for consistency and sensitivity at temperatures and problems considerably further than the array of standard utilization. Winchester ensures diligently-managed weights of primer mixtures, regularity in sizing and quality, precise measurements and winchester 41 primers tolerances for anvil heights and stability in extremes of temperatures and humidity.