If anything, I'd suggest buying a CAST of an Assault Rifle, since most decent-quality molds fly into the mid to upper hundreds of dollars. You'll also need Bondo, sandpaper, a dremel tool with attachments, some primer with paint and clear coat, a respirator, and high-end dust mask, and some long-sleeve clothing that you are willing to toss in the trash after you're done.
Also, you obviously haven't read ALL the stickies (not trying to sound mean), because you'd know to post in the Q&A topic in the sticky area of this forum (The Noob Forum). I'd suggest posting there after you have used the Search function and skimmed the stickies for your answer.
No one here is going to spoon feed new members all day long. A slip-up like this is alright ONCE, since you're new, but doing it again after being told not to, and Magnum will tear off your head.