Sierra MatchKing Features The Sierra MatchKing 105 grain bullet is engineered around a jacketed lead core with a hollow point boat tail design that minimizes drag and improves ballistic coefficient. Its G1 ballistic coefficient of 0.577 and G7 ballistic coefficient of 0.284 reflect the long ogive and small meplat that keep the bullet stable and efficient at extended ranges. Very thin jackets are drawn to an exacting concentricity standard of 0.0003 inch maximum variation which reduces bullet wobble in flight and tightens group sizes. This level of manufacturing precision is why MatchKing bullets are recognized worldwide for record-setting accuracy among competitive shooters. Each bullet s weight is held to within plus or minus 0.3 grain a tolerance that keeps shot-to-shot consistency high across a 500-count box. Sierra recommends a barrel twist rate of 1x7.5 inch or faster to properly stabilize this bullet at 105 grains in 6mm bore diameter. These bullets are designed strictly for target and match shooting rather than hunting applications since their construction does not provide the reliable expansion of lightly jacketed hunting bullets. For reloaders building precision loads for across-the-course or long-range competition the Sierra MatchKing 105 grain bullet delivers the accuracy pedigree this line is known for. Sierra MatchKing Specifications Manufacturer: Sierra Bullets Model: MatchKing Caliber: 6mm Bullet Diameter: .243 Bullet Weight: 105 Grain Bullet Type: HPBT Bullet Material: Jacketed Lead G1 BC: 0.577 G7 BC: 0.284 Rounds Per Box: 500 Recommended Twist Rate: 1:7.5 or faster Available At: GrabAGun