Winchester NATO-Spec Army Primers 41 are exactly the same primers Employed in the Lake Town 5.56mm ammunition. These primers are developed to exacting technical specs for shot to shot regularity. All primers are continuously and rigorously examined for consistency and sensitivity at temperatures and ailments far over and above the number of regular usage. Winchester guarantees meticulously-managed weights of primer mixtures, winchester 41 primers consistency in dimensions and excellent, specific measurements and tolerances for anvil heights and steadiness in extremes of temperatures and humidity.