Problem with reload animation

Im trying to animate my gun and hands in same animation. I trying to Add curve and select hand but then a new animation Window popup. Does hand and gun need too be a seperate animation , why cant i animate them in same animation ? What should i try ? Im only using unity3D

 

I see all these great games with AAA quality reload animations, but there is just so little information and tutorials about this. Making a seperate Hand and gun animation would be very hard too make them blend together.