After animating for a few days, I managed to finish the animation quite well. Getting some feedback from Anna-Camilla and some online friends I followed up a tip that the animation was a bit static. After sorting out some issues, the animation was done.
I played around with some camera perspectives, because I have always been really fond of first person perspective, so I animated a camera to make it look like the viewer is spinning the gun.
This is the final product: