How to blend animations and maintain the same movement?

I am trying to blend sprinting and reloading (fps shooter), however, a simple blend or an additive results in bad movement. Is there a blend that can be done to keep a precise movement from a animation on top of another without overwriting everything?

You can blend the two animations by using the sprint animation from the pelvis down and the reloading animation from the pelvis up.
Here’s a tutorial:
Merging Animations - #13 Unreal Engine 4 Animation Essentials Tutorial Series - YouTube

Here’s the official documentation on how to do what you want: