Winchester NATO-Spec Army Primers 41 are exactly the same primers Employed in the Lake Town five.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 considerably over and above the number of regular usage. Winchester guarantees meticulously-managed weights of primer mixtures, consistency in dimensions and high-quality, specific measurements and tolerances for anvil heights winchester 41 primers and steadiness in extremes of temperatures and humidity.