RPK is not there?

Hi! I just bought myself a RPK on the item market, i went in storage and i put it in my first bag, along with a desert eagle and a set of grenades... Now when i get in a game ( no matter what game ) and all i got on me is my desert eagle and my grenades... why?

PS: I've tryed to switch it of bags, and tryed to bring it alone too, nothing worked