Winchester NATO-Spec Military Primers 41 are the same primers Utilized in the Lake Town five.56mm ammunition. These primers are designed to exacting specifications for shot to shot consistency. All primers are continually and rigorously examined for consistency and sensitivity at temperatures and ailments considerably beyond the array of standard utilization. Winchester ensures thoroughly-managed weights of primer mixtures, regularity in dimensions and high-quality, specific measurements and tolerances for anvil heights and steadiness in extremes of winchester 41 primers temperatures and humidity.