here to suggest ar-15 lvoa/m4a1 or m4 carbine style rifle family, all military but in short basicly ar-15 familiy style military rifles such as lvoa, m4a1 m4a1 Carbine, or varients with a longer hardguard. as i see you already have pmags implemnted so they can be used to cut your work down... think theese would be amazing for the mod.