For me, my muzzle is at approx the same angle for both techniques.
Gun up in the workspace with the magwell pointing at approx 8 o'clock and muzzle at 11 o'clock. After the mag load I simply rotate my wrist so the only thing that changes is the magwell orientation moves to 2 o'clock, (muzzle stays the same) for the "sling shot", and my wrist only rotates halfway (magwell pointed away from me) for the hand over slide method.