Complex sentence: The low turret also limited the maximum depression of the main gun, since the gun breech had little room inside the turret to pivot on its vertical axis and the IS-3 was less able to take advantage of hull-down positions than Western tanks.
Split into simpler sentences: The low turret also limited the maximum depression of the main gun, since the gun breech had little room inside the turret to pivot on its vertical axis. As a result, the IS-3 was less able to take advantage of hull-down positions than Western tanks.