The Russian T-55 is blind and has not the same upgrades as the Slovenian M-55S. The Slovenian company Fotona produced electronic upgrades for the M55 and it has an L7 gun which was certainly already tested against Russian tanks by now.
The M-55S differs significantly from its historical predecessor. The tank has received a new gun - a 105 mm Royal Ordnance L7 with thermal protection jacket, one of the most successful tank guns of all time. The turret and hull have been provided with additional reactive armor, which has even changed the silhouette of the tank, making it more similar to modern tanks. The M-55S features a digital ballistic computer and gun stabilization, Fotona SGS-55 sight with laser rangefinder, Fotona COMTOS-55 commander's sight, improved engine, new rubber-metal tracks and even a LIRD-1A laser beam detector connected to the IS-6 smoke grenade launcher.
The L7 was built to knock out the T55. The Leo1 has even weaker armour but it can see 5 km far and also hit at further distances than the T55 also while driving.
A burried-in tank, well IDK how long it can survive with the now ubiquitous drones and smart munitions.
I would only use them at night and/or great distances. Open fire from 4km at 3am or so....
Fotona makes medical lasers today.
Fotona is a developer of high-technology laser systems for medicine (aesthetics, surgery, gynecology), dentistry & industry.
www.fotona.com