Reason finally prevails: the story of the Swiss Leopard 1 (Panzer/Char 77)
The haste with which the Swiss had ordered the Pz 68 led to the vehicle performing particularly poorly in testing. The 1st series of 170 vehicles was no better. When consideration was made for another small series of 50 (to reallocate money not spent on the Dassault Milan or A-7 Corsair II), intense objections arose. Comparative testing with a German Leopard 1 was the nail in the coffin for the national tank. It was decided to produce the new Leopard 1A3 under license.
It was decided to adopt a simpler and cheaper Swiss turret traverse mechanism, already developped for the Italo-German Leone export tank. The decision to restrict Pz 68 production to a single series proved fortunate, as the Leopard 1A3 and its components were already proven and reliable and the amount of fixes required for the Pz 68 was more limited without problems for later series. This allowed the Swiss to focus more on improving the combat capability of its tanks. As such they also selected the Belgian SABCA AVLS fire control system for the Panzer 77.
220 Pz 77s were produced between 1976 and 1982 at Thun. By 1982 the Swiss were on the verge of selecting the Leopard 2 for license production to replace the old Centurions. At the same time, the Germans were themselves developping an upgrade for their own Leopard 1s. The Germano-Swiss agreement of 1984 confirmed the upgrade of the Panzer 77 to the Leopard 1A5 (Pz 77V Verbessert) standard (but with a welded turret). This would involve the replacement of the SABCA AVLS with the better EMES-18 which offered greater commonality with the Leopard 2's EMES-15, as well as the installation of thermal sights.
The Pz 61 and 68, meanwhile were retrograded as lower-level tanks and the main improvements over their lifetime would focus on their standardization (namely removal of the Pz 61's 20mm coax with a MG), fixes of technical issues, adaptation to APFSDS ammunition and the addition of a laser rangefinder.
Some consideration was given for upgrading the Leopards further. A new composite armor package was tested on one vehicle in 1984-85. However concerns about the extra weight (especially weight distribution) and financial issues meant that no further actions were taken.
The Panzer 77 were finally retired in 1998 following budget cuts. Luckily, they were sold to another customer...