Winchester NATO-Spec Army Primers forty one are a similar primers used in the Lake City five.56mm ammunition. These primers are created to exacting technical specs for shot to shot regularity. All primers are continually and rigorously examined for consistency and sensitivity at temperatures and ailments considerably beyond the variety of standard usage. Winchester guarantees meticulously-controlled weights of primer mixtures, regularity in sizing and high-quality, winchester 41 primers specific measurements and tolerances for anvil heights and balance in extremes of temperatures and humidity.