I've been trying to make a useful hill/wall sniper out of the 2D2 since I first saw it. The Shadow Hawk feels like it was built around that shoulder ballistic and I can't really force myself to like the current Gauss mechanic. Since the 2D2 has the advantage of carrying an energy hardpoint on the same side as it's ballistic, I decided to drop in an erPPC for ranged punch and a UAC5 for dps. Paired with the UAC, the LRM5s are good harassment and critical killers when you catch an enemy in the open, and the TAG lets you put 'em to work quickly. I'd cram in four if there were weight for it, but alas, there is not. Even dropping out the erPPC for an erLL you run out of ammo on the LRMs too quickly to make it worthwhile. For people who want to surprise the cheeky light 'Mechs that try to take you to the brawl.