The Panzerschreck development was initially based on the American bazooka, captured in Tunisia, February 1943. The Panzerschreck was larger and heavier than its American counterpart - the Panzerschreck had an 88 mm calibre, compared to the 60 mm calibre of the bazooka - which meant that it could penetrate thicker armor, but also produced more smoke when firing. Calibre 88 mm was selected as the existing RPzB. Gr. 4312 for 8.8 cm Raketenwerfer 43 was reused for Panzerschreck. Warhead and fuzing was carried over, but the rocket motor's housing needed lengthening from to to accommodate the longer rocket motor. Raketenwerfer 43 had percussion firing, whereas for the Panzerschreck an electrical priming was selected, forming standard grenade RPzB. Gr. 4322. Other munitions were developed, including drill dummy, practice live rocket with inert warhead and standard grenade with improved contact system. The earliest production model of the RPzB 54 was long and weighed about when empty. Unlike the rockets used in American bazookas which extinguished before leaving the tube, the RPzB rockets kept burning for about after exiting the tube. Users were instructed to wear heavy gloves, a protective poncho and a gas mask without a filter to protect them from the heat of the backblast when the weapon was fired. Improvised shields were made to protect the user and in February 1944, the RPzB 54 was fitted with an official blast shield to protect the operator which made the weapon heavier, weighing empty. Small numbers of the shortened RPzB 54/1 were later produced. It had an improved rocket, a shorter barrel, and a range increased to about. Firing the RPzB generated a copious amounts of smoke both in front of and behind the weapon. Because of the weapon's tube and smoke produced, official documentation named the weapon the Ofenrohr. This also meant that anti-tank teams were revealed once they fired, making them targets and, therefore, required them to shift positions after firing. This type of system also made it problematic to fire the weapon from inside closed spaces, filling the room with toxic smoke and revealing the firing location immediately. Late war German tactical doctrine called for Panzerschreck and/or Panzerfaust teams to set up in staggered trenches no further than apart. In this way, attacking armor would face anti-tank fire from multiple directions at a distance of no more than. Anti-tank teams were instructed to aim for the thinner side or rear armor whenever possible. Allied armored units frequently attempted to add improvised protection to their tanks, e.g., sandbags, spare track units, logs and so on to protect against HEAT rounds. Another defense was to rig metal mesh and netting around the tank, resembling the German Schürzen auxiliary plates. In practice about 1 meter of air gap were required to substantially reduce the penetrating capability of RPzB, thus skirts and sandbags were virtually entirely ineffective against RPzB and Panzerfaust. In 1944, Germany provided the Panzerschreck to Finland, which used it to great effect against Soviet armour. The Finnish name for the weapon was Panssarikauhu. The Italian Social Republic and Hungary also used the Panzerschreck. Several Italian units became known as skilled anti-tank hunters and the Hungarians used the Panzerschreck extensively during Operation Spring Awakening.
