Flechette Blaster
Flechette Blasters are a type of weapon used by Adeptus Mechanicus Skitarii. A very interesting weapon, it occupies its own unique little page as it is neither a Stubber (The ammunition and firing mechanism is too advance and expensive to be considered Stubber category) nor is it an Autogun (It does not fire single solid slugs and its ammunition is way too specialized). A lightweight but lethal firearm, it is the favored tool of Sicarian Infiltrators. This silenced weapon fires hundreds of tiny darts, each of which bears a dormant cell awakened in the gun's chamber. Where one dart hits it emits a homing beacon that attracts others, resulting in a series of impacts that burrow through bone.
In terms of tabletop, these nasty little Pistols are available on the Infiltrators paired with a Taser Goad. It's got piss-poor strength at S2, but 5 (FIVE!) shots with shred means it pack more punch than a rapid-firing bolter against everything but T6/7 (which it cannot wound at all). Also grants that Pistol +1 Attack. Overall, it is a rather meh weapon that obviously suffers against enemy with decent armor. So stay clear from MEQ's and above.