Best way to Animate with models that interact with other models?

Hi there, so to begin with, I use Blender as an animation software and Unity 4 (free). Not sure if that's relevant but I'll include it anyway.

So my question is how to animate objects that interact with other objects. So for example if I have a character that is holding a gun. And this won't be the only gun he will be holding throughout the game. So I have the player model with an extra bone in his hand, and a weapon model. Then in Unity I attach the weapon to the extra bone.

So say that I need to do a reload animation for that gun involving touching the gun with both hands. How should this be handled? In the past I've loaded in the weapon (in blender) and animated it using the weapon, then when I'm done I delete the weapon from the model. Is this the best practice? Anyone who could shed some light would be much appreciated.

P.S. I use the @ annotation for saving animations so each animation is in it's own file.