Easton 9mm Crossbow Bolts 20 in Brass Insert Half Moon Nock 36 Pk Black. The 9mm Bolt has an inside diameter of 0.300" and will fit universal bolt components. Specifications for Easton 9mm Crossbow Bolts Brass: Manufacturer: Easton Color: Black Features of Easton 9mm Crossbow Bolts Brass: High-strength carbon construction Inserts are included with fletched bolt Shaft weight: 8.9 gpi BTV Vane: 10 grains 9mm Crossbow Insert: 61 grains Package Contents: Easton 9mm Crossbow Bolts Brass Easton 630080: 9mm Crossbow Bolts 20 in Brass Insert Half Moon Nock 36 Pk Black