I try to keep the guns as realistic as I can. The guns are sized realistically, and any bigger would be unrealistic, but I do see what you mean by them not fitting the hands.
If any of you remember the old 2007 stick figure animations, or Madness Interactive,

The guns were much more detailed than the player themselves. This is what I was going for. Most of the more modern and popular BL weapons look like they're stuck in 2005. I like the more "2015ish" style of weapons.