How do you go about making a reload animation?

For the last week or so I have been trying to use a imported reload animation, and a imported gun object. Currently I am just using some basic inverse kinematics to get the hand to hold the mag better than it does in the animation, once the animation finishes putting the mag in the gun I re-parent the mag to the gun. Then I attach the hand to the bolt and play the bolts animation with the hand attached. It doesn't look all too bad but I feel I am missing something very major. So basically my question is:

Are reload animations made custom for each gun with seperate hands attached to them, and then the hands are re-textured to give the illusion of a different person holding the gun? Or are basic reload animations used with some IK like what I am doing? Or is it something else?

If you have any questions about what I am using for IK, my models, or my scripts feel free to ask.