SMG-01 looking for critiques

thefoolau

And here's a few renders and the marmoset viewer file: https://www.artstation.com/artwork/RBvgv

This is based on a concept by Dillon Grubbs: More of his work can be found here: https://www.artstation.com/artist/dillon_grubbs

I was given a critique that the grip wouldn't work in real life? Any suggestions on how I could modify this to work better? Also, any other critiques would be greatly appreciated. Thanks