MAG 500 Qty 1/2" Inch Glass Marble Slingshot Ammo Solid Shot 500 14mm (1/2"+/-) Glass Sling Shot Ammo Some of the balls have imperfections such as flat areas, chips or size variations Great, affordable sling shot ammo Great for target practice or just shooting cans in the backyard and they are an affordable way to hone your skills. These should not be used as marbles due to ball imperfections.