Winchester NATO-Spec Army Primers 41 are exactly the same primers Utilized in the Lake Town five.56mm ammunition. These primers are developed to exacting requirements for shot to shot regularity. All primers are continuously and rigorously examined for consistency and sensitivity at temperatures and ailments considerably beyond the variety of ordinary use. Winchester guarantees cautiously-controlled weights of primer mixtures, consistency in dimension and winchester 41 primers good quality, exact measurements and tolerances for anvil heights and security in extremes of temperatures and humidity.