I love it on the Dreadwyrm Handgonne, makes a massive heffer of a weapon look even more over the top
But yeah I agree...on most guns it just looks a bit silly.
I don't mind the cast animation on its own, it's just when you're doing right after another skill (which is natural) it makes it look even more wavy and weird because your hands are desperately shifting around from the previous animation.
The main thing that bothers me isn't the barrel, but the running animation with weapon drawn...looks really silly when you'd imagine they'd hold it close to them with both hands.