Sniper Scope Zoom/FOV

When using any sniper rifle and any scope, around half of the time the scope does a strange zoom in/fov change temporarily when shooting. Its very noticeable on the area around the outside of the scope. I don't think this is intended. Its a consistent thing in every match for me. I have tried different scopes on different snipers and it still happens. It only happens for a split second after shooting, but it doesn't happen every shot. I'm on PC/Steam.