Winchester NATO-Spec Military Primers 41 are exactly the same primers Employed in the Lake Town 5.56mm ammunition. These primers are created to exacting technical specs for shot to shot regularity. All primers are continually and rigorously examined for regularity and sensitivity at temperatures and disorders far past the choice of normal usage. Winchester guarantees very carefully-controlled weights of primer mixtures, consistency in dimension and good quality, exact measurements and tolerances for anvil winchester 41 primers heights and security in extremes of temperatures and humidity.