Winchester NATO-Spec Armed service Primers 41 are the same primers Utilized in the Lake Metropolis five.56mm ammunition. These primers are constructed to exacting requirements for shot to shot regularity. All primers are regularly and rigorously analyzed for regularity and sensitivity at temperatures and circumstances significantly outside of the selection winchester 41 primers of typical utilization. Winchester ensures thoroughly-managed weights of primer mixtures, regularity in sizing and quality, specific measurements and tolerances for anvil heights and stability in extremes of temperatures and humidity.