Panzerkampfwagen III Ausf.H was only one temporary solution, while waiting for the production of a production version with better armor, Panzerkampfwagen III Ausf.J. This one made its appearance in 1941 with an integral frontal and back shielding, thick of 50mm. At the interior the levers replaced the pedals actuating the steering brakes.

Panzerkampfwagen III Ausf.J with the 50mm KwK L/42 on the Eastern front.

src: site "Germany's Vehicle History"

After the campaign of France, Hitler ordered that the principal armament of Panzer III was to be the 50mm KwK L/60. But because of difficulties of provisioning, these instructions were initially ignored well that the face-to-face with the guns of 76.2mm of Russian T-34/76 and Kv-I were often unfavourable! This nonobedience of its kinds, made Hitler furious and this one made turn over the models already produced in Germany to be rearmed there with KwK L/60 of 50mm. The loading of ammunition for this gun was limited to 78 rounds.

Panzerkampfwagen III Ausf.J during a passage to ford.

src: site "Germany's Vehicle History"

Panzers III Ausf.J armed with the gun of 50mm L/42 will keep the Sd.Kfz.141 number whereas those armed with the 50mm L/60 receive that of Sd.Kfz.141/1 and will be also called J1. Panzer III Ausf.J (50mm L/42) was manufactured with 1549 specimens by the firms Daimler-Benz, MAN, Alkett and Henschel between March 1941 and July 1942 whereas Panzer III Ausf.J1 (50mm L/60) was manufactured with 1067 specimens by firms Daimler-Benz, Alkett, Henschel, Wegmann, MNH, MIAG and MAN between December 1941 and July 1942.

Panzerkampfwagen III Ausf.J armed with 50mm KwK L/60.

src: site "Germany's Vehicle History"