grizlybear45
New member
to all my fellow gunners, i have a question, if you please? i am getting ready to build an ar-15. i've been looking up parts and have found quite an assortment. i was wondering if someone would explain the differences between a1,a2,a3,a4,m4, and carbine. i want to build a flat top for personal use and would like to build one for matches which i understand can't be a flat top. any definitions and or advice would be greatly honored. thanks