Hornady A280Ai Lock-N-Load Modified Case 280 Ackley Improved This Case Is specially Modified To Work With Lock-N-Load Precision Gauges. A Special Fine Thread Is Used To Attach Them To The Gauges, ensuring That They Remain perfectly Square For Precise Alignment In The Chamber Of Your Firearm. The Neck Of The Case Is Made perfectly Round And Opened slightly To Allow a Standard Diameter Bullet To Slip Into The Case Mouth effortlessly, But Concentrically, To Ensure The Most Precise results Possible. Type: Unprimed Brass Material: Brass Gun Type: Rifle Caliber Or Gauge: 280 Ackley Improved Recommended Usage: Reloading