So I've been running for around a year or two a very successful DH game. Characters are around rank 5 or 6, and the game is heavily story/investigation driven (I wrote the pinned article on conspiracies in the gamemaster forum) but I throw in combat every couple sessions.
This past session I had, due to machinations and the PCs not playing it low-key, an HTR Arbitrator squad breach & engage the PCs, who decided that walking fully armed and armored into an influential neighborhood wasn't going to have repercussions. Firefight ensues. I will say that cyber mastiffs are effing SCARY in combat. Huge armor & toughness, crazy damage, the big downside is that they don't dodge very well. Anyway, the fight kind of spiraled out of control and while nobody died, the new-ish player who rolled an assassin expressed his... displeasure with how combat went. He managed to one-round headshot the tech priest handling the mastiffs, which actually made the fight doable instead of a slaughterhouse. This was due to the tech priest not wearing a helmet (an intentional decision on my part). After that though, he basically was unable to burn through the toughness and armor of the arbitrators (carapace 6 toughness 3) and only managed to do one or two points of damage after that for the rest of combat. While he wasn't "complaining" about this particular combat, he asked me if there were ways to make a gun-toting assassin more effective against armored opponents. Especially since we've got an IG with a heavy stubber who can usually burn through heavy soak on a full round burst, a psyker who gains a strength bonus of 12 when he pops claws, a cleric who found the eviscerator chain greatsword and bought the elite advance allowing him to handle it safer (and now is throwing like pen 5 attacks), and grenades/missiles on occasion.
I get it and agree, he and the tech priest are under-gunned at this point, and combat bogs down a lot when you're only plinking for a point or two here and there. Yes, he is a god against unarmored targets, but aside from leaving bad guys without extremity armor (arms, legs, head), we're trying to figure out how to step up his weapons.
At the moment he's going with guns, and is partial to dual pistols, but has expressed a willingness to go to a rifle if needed. Nobody has access to plasma or any of the really scary stuff, and all he needs is maybe an extra point or two of damage and some armor penetration to make him feel like he's at least contributing. The Tech Priest is in a similar situation, though he just discovered servitors so I think he's going to become a drone commander and I'm not quite so worried about him.
My problem is that I'm running a 3 ring circus of locations, conspiracies, NPCs, and tangential plots, and my mind is mush from that alone. I don't have time to pour through all my books and look for appropriate weapon/accessory combinations, so I was hoping to get some input from folks who have successfully deployed such weapons packages. Right now he tends to either stick with needler pistols out of the core book or a long las with a couple of attachments like a laser pointer. As I said, a couple more AP points and maybe a point or two more of damage and we'd be in an area where he doesn't have to roll max damage to inflict 3 wounds (which is significant, but it also means that 2/3 of *successful* attacks basically bounce off).
I have most of the rules books (I don't touch the adventures), including the handbook, the arbitrator book, the martyr book, and others (I'd have to check them all). Any help would benefit things for me immensely. I'm not looking for "broken", I'm looking for "on par with the rest of the party".
Thanks in advance!