Your grip section appears to be very squished.



Note: I would like it to be known that I'm not saying you should be overlapping. But That you need to fit these things within that space. If you have to make the gun longer or something. The only thing I keep thinking is that a Spartan's hand has to fit in that, and at the moment I don't really see that happening. But I may be wrong. But it's difficult to really tell without a render of the side view of the actual gun. Not trying to be mean, just trying to get you a good model.

The other thing I've noticed is that in Bungie's model, they actually have the scope sitting on the rail, yours is not. So I would suggest lengthening the rail and placing the scope on top of it.

Other than that it looks like a nice model. Would love to see it in game soon.

Edit:
Also, the notches on the grips need to be able to fit a finger between, your notch between the trigger guard and the first extrude is way too small.