Winchester NATO-Spec Military Primers forty one are a similar primers Utilized in the Lake Town 5.56mm ammunition. These primers are built to exacting requirements for shot to shot regularity. All primers are consistently and rigorously analyzed for consistency and sensitivity at temperatures and ailments far outside of the array of ordinary usage. Winchester ensures diligently-controlled weights winchester 41 primers of primer mixtures, consistency in measurement and quality, precise measurements and tolerances for anvil heights and balance in extremes of temperatures and humidity.