Winchester NATO-Spec Armed forces Primers 41 are the same primers Utilized in the Lake Metropolis five.56mm ammunition. These primers are constructed to exacting specs for shot to shot regularity. All primers are frequently and rigorously tested for winchester 41 primers consistency and sensitivity at temperatures and situations significantly further than the selection of typical 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 temperatures and humidity.