how to cycle through weapons in far cry 3?

Hi, I've got the PC version and I don't have the multi-weapon slings yet, but when I go to the store it says that I own several weapons (like bow, SVD, AK). But when I go on a mission, I have the AK and once I run out of bullets, I can't access the bow or the SVD, I can only switch to a mine or grenade. I've held down the 1 key and it shows only the AK at the top and the explosives on the sides, the other weapon slots are locked. I tried pressing x, that only switches between the AK and the mine. What am I missing? Or can I only take one weapon with me at a time until I get more slings and even though I own more weapons I can't carry them with me? Thanks!