Nice, is that a straight 1:1?
I think it needs to be longer. Remember when you first saw the UT3 shock rifle and you though "Jeez, that's looong", I think the LG needs to be as long, or at least feel as long.
I think the front would look better if it had more segments. Currently it has one big metal plate wrapped around the top, with the lightning guts underneath. I think open it up a bit more, split the plate up into several more segments, with more seems and gaps you can see inside through.
The handle (butt?) seems a bit chunky and small, doesn't feel like a big burly UT3 guy can fit his hand inside the grip. Make it longer at the back, and open up the grip, so it's not enclosed.
This might be a random idea, and it might be better to explain if I just drew it in paint, but anyway.
The scope, from what I remember, you look at the screen for the scope. Which indicates to me that there should be a camera on the front end of the gun. So playing with that idea, you could put a small bump at the front with a small lens on it, but it'll just look like a normal scope. To make things interesting, how about putting 2 bumps on it with 2 lenses? Seems a bit bizarre, but why not.
And depending how you place them, you could give the gun a lot of character, because from the front it would like like a cute little face, with two eyes, big long nose and a mouth that shoots Lazors! at you.
That makes sense right?