Custom Built Arms is America's Gun Shop. We offer a wide selection of AR 15 parts and items, including: AR 15 uppers, AR 15 lower parts, gun furniture, sights, optics, magazines, holsters, and etc. Custom Built Arms strives to provide the best quality customer service in the industry. Custom Built Arms offers the best value and low prices on AR 15 parts and items. Choose Custom Built Arms the next time you want to buy any AR 15 parts or items.