Well, I think it still deals damage, but it's just sort of annoying not to see the big explosion to know for sure. If I hit a clot or something weak it'll usually blow up, but if I'm dealing with a fleshpound or scrake I can't really tell. It happened a few times with Hans Volter and his HP counter went down, so I think the damage is still dealt, but it's sort of annoying to have no visual or audio indicator that your big explody thing did anything. And it just looks and sounds like they suck in your round with no effect. I think I was playing with Sharpshooter initially
I looked it up and I was playing Gunslinger initially and honestly it's one of the crappiest perks whose weapon progression sucks. That's my only gripe with the expanded classes, weapon progression sucks on some of them. Gunslinger and Sharpshooter need to be merged again or they need more weapons. I'm used to KF where I can have double Desert Eagles and something else of substance within the perk. Even Demo, which is becoming my favorite lately, needs something more useful between the grenade pistol and the RPG. I just stick with the grenade pistol for most of the game and then get the RPG for the boss fight at the end. We need a grenade shottie or just something in between.