Winchester NATO-Spec Armed service Primers 41 are exactly the same primers Employed in the Lake Town 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 winchester 41 primers conditions much over and above the number of regular usage. Winchester ensures thoroughly-managed weights of primer mixtures, regularity in dimensions and quality, specific measurements and tolerances for anvil heights and stability in extremes of temperatures and humidity.