Whitch type of shell is that AP(lg)?
and I find this:
the BR412 as being developed in the mid 40s with the 100mm D10 gun and the BR412B and BR412D being developed during the 1946 through 1950 time frame
and in Russian Battlefront:
A new commander's cupola was installed on the roof as well as MK-IV observation sights, also a pair of the new ventilators were mounted to combat with asphyxiating powder gases. Generally, the 72% of the SU-100's parts were borrowed from original T-34, 4% taken from the SU-122, 7.5% - from SU-85 and only 16.5% parts were new. The 100 mm long barreled (56 clb) D-10S gun was supplied by 18 armor piercing rounds BR-412B and by 15 fragmentation/HE rounds OF-412. Having a 895 m/s muzzle velocity, the BR-412B with a blunt ballistic cap was able to penetrate ~100 mm armor sloped at 60° at range of 1500 metres.
Notwithstanding, there were a known problems with the D-10S, its fine tuning continued till the summer 1944. Moreover, there were large problems with mass production of the BR-412B, the technological process was too complex and final production was of low quality resulting a reduced armor penetration. Thus, the mass production of the SU-100 was delayed until problems with ammunition won't be solved. They were resolved by November-December 1944. Until that date, the mass production of the SU-85M was launched instead. In December 1944, the manufacturing of the Su-85M was cancelled and mass production of the SU-100 was started instead.
So BR-412B did entered the GPW, while BR-412D did not?