To avoid creating an extra thread, I will post all of the issues I have with the underbarrel grenade launcher here: 1. 50% of the time, it prevents me from switching back to bullet firing mode. I have to switch to pistol and then back to my primary. Many times I have died from this. 2. The ammo resupply - WHY IS IT SO RANDOM? I've had an ammo box resupply me with just 1/2 grenades. 3. Hits sometimes don't register. Once, I hit a max straight in the chest and killed him. I fired one into another max right beside the first one, hit him in the chest, saw a big explosion, but didn't even get a hit marker. 4. It moves the rest of your weapons down a slot. As an engineer, I press 3 expecting a repair gun, but no, I get a pistol and start shooting the max I want to repair. I suggest making underbarrel attachments replace the single shot firing mode, so you switch to it by pressing B. Seriously, why would the pistol slot change?