Winchester NATO-Spec Armed forces Primers 41 are exactly the same primers Utilized in the Lake Town five.56mm ammunition. These primers are constructed to exacting requirements for shot to shot regularity. All primers are winchester 41 primers constantly and rigorously tested for consistency and sensitivity at temperatures and problems significantly beyond the array of usual use. Winchester assures diligently-managed weights of primer mixtures, regularity in sizing and high-quality, specific measurements and tolerances for anvil heights and steadiness in extremes of temperatures and humidity.