When casting custom blanks, we cast them in batches of 3, so you get a discount when ordering 3 instead of 1! buy 2 get one FREE! Customize your own barrel today! You can choose up to 4 colors that you need in a barrel, you can choose if you want the colors swirled or stacked, and you can choose if you want a Duck barrel (5/8 bore) a goose barrel (5/8 to a 7/8 Bore), a grunt barrel (3/4 Bore), a duck insert blank, or a Solid core blank (No bore, 1.5x3)