Rules-wise, Space Marines can wield a Bolter one-handed. Keep in mind, not a bolt pistol, but a Holy Bolter or Boltgun or whatever else it's called. Now the fun stuff: according to the rules of the Deathwatch game, you can actually auto-fire both your bolters if you purchase two or three talents. Yeah, that's painful.
Also, it's not the first time we see pistols dual-wield on a Marine. A name comes to mind, and the name is Cypher the Fallen, formerly of the Dark Angels ^_^
Dual-Wielding Pistols?
Rules-wise, Space Marines can wield a Bolter one-handed. Keep in mind, not a bolt pistol, but a Holy Bolter or Boltgun or whatever else it's called. Now the fun stuff: according to the rules of the Deathwatch game, you can actually auto-fire both your bolters if you purchase two or three talents. Yeah, that's painful.
Also, it's not the first time we see pistols dual-wield on a Marine. A name comes to mind, and the name is Cypher the Fallen, formerly of the Dark Angels ^_^