Winchester NATO-Spec Military Primers forty one are the identical primers used in the Lake Town five.56mm ammunition. These primers are designed to exacting requirements for shot to shot regularity. All primers are consistently and rigorously analyzed for regularity and sensitivity winchester 41 primers at temperatures and ailments far outside of the array of ordinary utilization. Winchester ensures cautiously-controlled weights of primer mixtures, consistency in measurement and high-quality, specific measurements and tolerances for anvil heights and stability in extremes of temperatures and humidity.