general-purpose main gun that fired both anti-tank and high explosive ammunition) that had a longer barrel than could be mounted in a turreted tank on the same chassis. The lack of a turret increased the vehicle's internal volume, allowing for increased ammunition stowage and crew comfort. Eliminating the turret let the vehicle carry thicker armour, and also let this armour be concentrated in the hull. Sometimes there was no armoured roof (only a weather cover) to keep the overall weight down to the limit that the chassis could bear. The absence of a turret meant that tank destroyers could be manufactured significantly cheaper, faster, and more easily than the tanks on which they were based, and they found particular favor when production resources were lacking. Germany The first German tank destroyers were the Panzerjäger ("tank hunters"), which mounted an existing anti-tank gun on a convenient chassis for mobility, usually with just a three-sided gun shield for crew protection. For instance, 202 obsolete Panzer I light tanks were modified by removing the turret and were rebuilt as the Panzerjäger I self-propelled 4.7 cm PaK(t). Similarly, Panzer II tanks were used on the eastern front. Captured Soviet anti-tank guns were mounted on modified Panzer II chassis, producing the Marder II self-propelled anti-tank gun. The most common mounting was a German anti-tank gun on the Czech Panzer 38(t) chassis as the Marder III. The Panzer 38(t) chassis was also used to make the Jagdpanzer 38 casemate style tank destroyer. The Panzerjäger series continued up to the equipped Nashorn. German tank destroyers based on the Panzer III medium tank and later German tanks had more armour than their tank counterparts. One of the more successful German tank destroyers was designed as a self-propelled artillery gun, the Sturmgeschütz III. Based on the Panzer III tank chassis, the Sturmgeschütz III was originally fitted with a short barreled low-velocity howitzer-like gun, and was assigned to the artillery arm for infantry fire support as an assault gun. Later, after encountering Soviet tanks, it was refitted with a comparatively short-barreled high-velocity anti-tank gun, usually with a muzzle brake, enabling it to function as a tank destroyer. The Sturmgeschütz III from its 1938 origin used a new casemate-style superstructure with an integrated design, similar to the later Jagdpanzer vehicle designs' superstructure, to completely enclose the crew. It was employed in infantry support and offensive armoured operations as well as in