If you’re into miniature weapons for decoration, check out Goat Guns! They sent me two M4s in FDE. They are about a foot long in length at a 1:3 Scale. All the parts are die cast metal and the attention to detail is excellent. The rear A2 sight on the carry handle is adjustable, charging handle is functional as well as many other parts. Here is the link to the same M4s that I have:
Their selection is huge, it includes the Barrett M107 and more are coming!