Easton 9mm Carbon 22 -Inch Crossbow Bolt 36 Pack - Easton’s 9mm Bolt is constructed from high-strength carbon and has an inside diameter of .300”. These bolts fit universal bolt components and come with factory installed, aluminum inserts and halfmoon nocks. High-strength carbon construction 397 grains ID: 0.300 OD: 0.344 Shaft weight (GPI) : 8.9