When I think about some of the weapons that have been confirmed, there are a few that strike me as .44 magnumish. At least in the sense that they might not be widely used in-game. I don't have a problem with good weapons and their ammunition being rare(sniper rifle and .308), but I'm not wild about them being non-existant(scoped .44 and .44 mag).
I can understand the Fat Man, but really there isn't a reason why the rest of the weapons can't be more utilized. If anything, it will add to the challenge which lots of people seem to want.
I think with a wider variety of weapons using .308 and other ammunition types that were pretty rare in FO3 it'd be detrimental to have a slew of new firearms and not be able to keep a relatively healthy supply of bullets for them. If you think about it the M1 Garand style rifle is most likely chambered in .308 if we get as much .308 ammunition as we did in FO3 the weapon will be damn near useless I'm all for making certain ammunition types rarer than others but only to a point, FO3 had a lot less variety in firearms so I could live with being forced to use the one with the most plentiful ammo pool. (I can recall having barely over 200+ .308 rounds in my whole (main) playthrough of FO3, although I may just be unlucky I even had Scrounger but still couldn't ever get any of those bullets.) :tops: