maybe you can't put that ammo into that weapon. I loaded bowcaster with 5 round powercell several days ago just fine, by raging the ammo onto the weapon, in the equipment screen, not the little box with green man that shows what you have where.
I is having the same problem loading a weapon myself at the moment. Unable to load it either carried or dropped, and weapon is unloaded. However I'm using IE and silly government computer's with outta date everything, so I'm putting eet down to that and trying again later with Firefox ... lol
Ok, the dl-44 is not loaded, I've dropped both weapon and ammo to the ground, doesn't matter if I have in hand or on ground whenever I drag the ammo to the gun it just goes back to where it was before, the gun remains unloaded. Please someone tell me I'm not going crazy and that this is some kind of qlitch.