I'm really liking the new revolvers even with the masher accessory. I really hope they start popping up. They were pretty rare in the first game.
I did find a double shot jacobs early on that was pretty beast for the first few chapters. It used to 2 rounds per shot, held 14 (for 7 shots), and did 25x2 damage when most single shots were around 30. I was dropping 2-3 bullymongs per reload at the time.