Bolters fire bolt rounds, which are self propelled explosive shots. So basically little missiles that explode once they are inside the enemy. I guess since the shot is self propelled, it doesn't need as long of a barrel? That's the best excuse I can think of.
I wonder how Space Marine equipement will look on Deadpool(even through armor is probably more then a dozen sizes to big, but I doubt that'll stop him from trying it out. And he will definetly like to try out those weapons)
Pfff jope Fonte... esque da gusto ver tus marines.... Algún dia (muy lejano) tendré la misma tecnica que tu.... (ni en sueños...) Está chulisimo el Ultramarine. Si yo te diera una idea para que dibujases uno, lo harias ???