Midsouth is now offering the winchester usa ready 9mm Match Large Rifle Primers in 1000 Count from Winchester. Winchester Match Primers are the same primers used in the match grade Winchester USA Ready ammunition. All primers are constantly and rigorously tested for consistency and sensitivity at temperatures and conditions far beyond the range of normal usage. These primers are built to exact specifications for shot-to-shot consistency. Winchester guarantees better sensitivity for more positive firing in all guns, carefully controlled weights of primer mixtures, consistency in size and quality, precise measurements and tolerances for anvil heights, and stability in extremes of temperatures and humidity.