How to Move the object "Natural" by C++?

Why not add a movement component in your Actor header ? It should work in cpp

in .h

UProjectileMovementComponent* MoveComp;

in cpp,

AYourActor::AYourActor(const class FObjectInitializer& PCIP)
{
    ProjectileMovement = PCIP.CreateDefaultSubobject<UProjectileMovementComponent>(this, TEXT("ProjectileMovement0"));
}

see this post