Hellgun
The Hellgun is an advanced variant of the IG lasgun. While the lasgun fires at a fairly rapid semi-automatic rate with a full auto setting, the hellgun is capable of firing extremely rapidly at full auto nonstop, allowing the user to bring the Empra's light faster and more deadlier than the standard-issue Flashlight. Besides the fact that it needs to use a back-pack mounted battery to use, it requires extensive maintenance and only issued to elite Imperial guard troops like the Kasrkin, however the back-pack mounted battery gives a hellgun or hellpistol an effectively infinite amount of shots, which is very handy when you're facing orks, traitor guardsmen/heretics/cultists, and Tyranids. It's almost on par with a bolter, but it is way easier on the quartermaster due to the aforementioned limitless number of shots. For some fucktarded reason they are getting replaced by hotshot lasguns which are essentially just regular lasguns with supercharged shots. Ehhh, Dark Heresy has rules for both weapons. Creed has two pistol versions of them on his belt.
What the heavy stubber is to autoguns and what the stormbolter is to bolters, the hellgun is to lasguns. The Autoguns and Lasguns both kind of skip out on the Heavy Bolter equivalent (What about the autocannon and lascannon? Sure they are more powerful but they have a lower firing rate to even it out). Uh, multilasers?