Warhammer 40K Fluff Discussion XV: You Must Be THIS Tall To Witness The Grimdark

[The Glyphstone]

Depends on the model of HB, if it's drum fed then yeah they can pick it up, if it's belt fed then it's going to take a while to get it off the dead guy and properly attached to the living one. Sure you can use it without attaching the backpack ammo box to yourself, but then you can't retreat with it.

Eh, according to Deathwatch a Space Marine has an absolutely absurd carrying capacity. He can just heft the corpse of the dead guy in one hand and the Heavy Bolter in the other and carry them around that way.

(in the game itself, the Ammo Backpack is an optional add-on. You can have regular drum magazines, or the continual belt-fed from a backpack supply. Doesn't interfere with the power supply in any way.)