Issue Rigging a Tool to a Dummy

What’s the problem?
I am attempting to rig up a dummy so that I can start animating with a tool in the rig. However, upon creating a Motor6D between the RightUpperArm and the Handle of the tool the RightHand position changes. Deletion of the Motor6D corrects the hand position.

Also, during animating the RightHand refuses to follow directions when creating keyframes. It teleports to positions that I did not tell it to.

What I’ve tried.
I have been browsing the forums for a bit now and I can not seem to find a definitive answer. I have tried messing with the positioning and orientation of the RightHand, but it magically changes back those properties as soon as I change them with the Motor6D still connected.

The rig before enabling the Motor6D:

The rig after enabling the Motor6D:

The rig’s hierarchy:
image

Extra information: The “NewAK-47” tool is rigged properly. All parts are unanchored and have a connection to the tool’s handle with either a weld or a motor6d.

If someone could possibly help me understand why this is happening and how to fix it it would be greatly appreciated.