Board Thread:Warhammer 40k General Discussion/@comment-6589306-20130228113457/@comment-3258762-20130303183544

Well, for such fluid movements, having only an exoskeleton would make little sense. If you look at insects (with their exoskeletons) they move in devastating trashes, because their musculature is situated in different positions, meaning that fluid movements are not as easy to perform. Having an endoskeleton as well would give them a more fluid channel for their nerves to travel, thus giving them faster reaction time, and the fact that the musculature would be connected to the endoskeleton, meaning it can perform more subtle motions.

As for the bolter rounds - .75 calibre self propelled submunition warheads.