Starline Brass Unprimed Cases 10mm Auto 100/Pack The 10mm Auto Was Designed Primarily For Law Enforcement But Was quickly abandoned In Favor Of The .40 S&W. Now Making a Comeback, This .40" Caliber Handgun Is More Powerful Than The .45 Auto With higher Magazine Capacity. Type: Unprimed Case Material: Brass Style: Large Length: 0.984"-0.991" Gun Type: Pistol Caliber Or Gauge: 10mm Quantity: 100 Per Bag Recommended Usage: Reloading