Winchester NATO-Spec Navy Primers 41 are precisely the same primers Utilized in the Lake Town 5.56mm ammunition. These primers are constructed to exacting specifications for shot to shot regularity. All primers are frequently and rigorously tested for consistency and sensitivity at temperatures and ailments significantly outside of the choice of standard usage. Winchester assures diligently-controlled weights of primer mixtures, regularity in dimensions and good quality, precise measurements and tolerances for anvil heights and steadiness in extremes of winchester 41 primers temperatures and humidity.