I think I've been playing this game long enough now that I should be able to carry more than one primary weapon, but still all I can do right now is swap one for another. When I bring up the wheel there's no extra slots on the primary weapon like there is for melee weapons.
What on earth do I have to do to get more slots on primary weapon? I've looked through all the perks, but the only ones relating to weapons are for faster switching and less sway.
This game is brilliant, it really is, but it's about as intuitive as... something that's not intuitive at all.