Winchester NATO-Spec Armed forces Primers forty one are precisely the same primers Employed in the Lake Town five.56mm ammunition. These primers are crafted to exacting specifications for shot to shot regularity. All primers are continuously and rigorously examined for consistency and sensitivity at temperatures and circumstances far beyond the range of normal utilization. Winchester guarantees diligently-managed weights of primer mixtures, consistency winchester 41 primers in sizing and quality, specific measurements and tolerances for anvil heights and security in extremes of temperatures and humidity.