A report by the Usage Department of the Armoured and Mechanized Warfare of the 2nd Ukrainian Front in February and a report of the NKTP inspector's group at the 1st Belorussian Front in May indicated vases where the gearbox of the T-34 tank with an 85 mm gun broke when the gun was fired on the move.
These reports propose the installation of a muzzle brake on the 85 mm gun to protect the transmission from damage and breakdowns.
Reliability trials of T-34 tanks with 85 mm D-5 and S-53 guns, IS-122 tanks, as well as SU-85 and SU-152 SPGs performed in May-June of this year at the GBTU NIZT proving grounds consisting of firing the gun on the move when driving in 1st, 2nd, and 3rd gears as well as during switching from the 1st to the 2nd, from the 2nd to the 3rd, and from the 3rd to the 4th gears, followed by a 30 km march, showed that:
- The transmissions of T-34 tanks with the 85 mm gun, IS-122 tanks, SU-85 and SU-152 SPGs work normally when firing their stock S-53, D-5, D-25, and 152 mm guns on the move. No breakdowns or issues were found in the transmission during trials.
- The recoil from firing has no practical effect on the stability of tanks and SPGs.
- The installation of a muzzle brake on the 85 mm S-53 gun to reduce the recoil energy is senseless (not to mention it will require a redesign of the recoil system).