Winchester NATO-Spec Navy Primers forty one are precisely the same primers Employed in the Lake Town 5.56mm ammunition. These primers are created 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 standard winchester 41 primers utilization. Winchester assures diligently-managed weights of primer mixtures, regularity in sizing and quality, precise measurements and tolerances for anvil heights and stability in extremes of temperatures and humidity.