https://thesovietarmourblog.blogspot.com/2017/01/t-54.html "The maximum chamber pressure of all D-10T models is 289 MPa. It is directly equivalent to the M3A1 90mm and 20. pdr (84mm) cannons in that respect, but due to the longer barrel, large ammunition (100mm D-10T cases are 88mm longer than 105mm L7 cases) and large caliber, D-10T could be considered to be in a league of its own. By the late 50's, advances in cannon technology allowed the improved M36 90mm and L7 cannons to compete directly with the D-10T by using hotter load ammunition. In 1958, T-55 tank was introduced with D-10T2S." "the end result was much the same, as the energy of the projectiles coming out of both of these guns is often practically identical. Surprisingly, an L28 projectile assembly - weighing 5.8 kg with sabot and penetrator both included - travelling at 1470 m/s at the muzzle has only 117.8 kJ more energy than a 15.88 kg BR-412B projectile flying at 880 m/s. This is a lot, but due to the enormity of the power involved, this sums up to an energy advantage of only 1.88%. Generally speaking, both guns had the same power, only different ammunition technology. Western ammunition was generally more advanced, being smaller and lighter but packed with propellant with a higher energy density." D-10T was not inferior to the L7 early in the latter's career, but the L7 had much more potential.