Winchester NATO-Spec Army Primers forty one are the identical 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 ordinary usage. Winchester guarantees meticulously-controlled weights of primer mixtures, consistency in measurement and excellent, specific measurements and winchester 41 primers tolerances for anvil heights and security in extremes of temperatures and humidity.