Winchester NATO-Spec Military Primers 41 are exactly the same primers Utilized in the Lake Town 5.56mm ammunition. These primers are created to exacting technical specs for shot to shot consistency. All primers are consistently and rigorously analyzed for winchester 41 primers regularity and sensitivity at temperatures and circumstances much outside of the selection of standard utilization. Winchester assures carefully-managed weights of primer mixtures, regularity in size and top quality, exact measurements and tolerances for anvil heights and security in extremes of temperatures and humidity.