Winchester NATO-Spec Military services Primers forty one are the exact same primers Employed in the Lake City 5.56mm ammunition. These primers are created to exacting technical specs for shot to shot regularity. All primers are winchester 41 primers continuously and rigorously tested for consistency and sensitivity at temperatures and problems significantly further than the selection of typical utilization. Winchester ensures meticulously-managed weights of primer mixtures, consistency in measurement and excellent, specific measurements and tolerances for anvil heights and security in extremes of temperatures and humidity.