In this picture F1D0 shows off the mechanics of his palms, Digistruction! He can create anything willingly, whether it be a gun or a magazine he can create it.
Though with how big the digipads are, their main use is for small arms like pistols and SMG's, magazines to feed those guns and melee weapons. Although he is able to create larger guns, he has to create the individual smaller parts and put them together.
Digistructing items comes with a cost though, creating objects drains his power cell and although a gun and a magazine alone isnt too much of a usage on his power, in a long term battle, those magazines can pile up and sooner or later he's going to need to recharge.