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 technical specs for shot to shot regularity. All primers are continuously and rigorously examined for consistency and sensitivity at temperatures and ailments considerably beyond the array of usual use. Winchester assures diligently-managed weights of primer mixtures, regularity in sizing and high-quality, specific measurements and tolerances for anvil heights and winchester 41 primers steadiness in extremes of temperatures and humidity.