He doesn't actually bring a weapon to you that I have seen....but if you have him in party, you will notice you get ammo, and loot from enemies when he is around them. So I think the mechanic is more an auto-loot function than a bring a weapon to you function....and since most of the weapons dropped are pretty basic, I will take this gameplay mechanic.
Maybe this changes if you are one short on weapons....but I haven't ever personally seen him bring an actual weapon, just the auto-loot function.