Winchester NATO-Spec Armed forces Primers forty one are precisely the same primers Employed in the Lake City 5.56mm ammunition. These primers are created to exacting technical specs for shot to shot consistency. All primers are continually and rigorously examined for regularity and sensitivity at temperatures and disorders far past the choice of typical utilization. Winchester winchester 41 primers ensures meticulously-managed weights of primer mixtures, consistency in measurement and good quality, exact measurements and tolerances for anvil heights and security in extremes of temperatures and humidity.