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 a specialised form of Galvanic Weapon. A lightweight but lethal firearm, it is the favoured 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 rather low strength at S3, but 5 (FIVE!) shots means it packs almost as much punch as a rapid-firing bolter, while being fireable in melee. Overall, it is a rather meh weapon that obviously suffers against enemy with decent armour. So stay clear from MEQs and above.