I take it back then, that's pretty awesome that you converted a motorcycle helmet into a Halo helmet.
I haven't made any weapons yet, so nothing super helpful comes to mind. I'm sure you know to cover the cardboard edges with thin foam. Anywhere that is curved you cut angles into the cardboard and use one piece of foam, bending it over along the edge to make a nice smooth grip. Otherwise, it is looking good. I like the classic CE AR you went with.