Why does the French FR 49 - M61 With same velocity seem to have less, well velocity-?

Game Discussion General Discussion
1

I’ve noticed something odd when using the French FR 49 ( AMX-13 (FL-11), E.B.R (1951) ) with M61 ammo. On paper, the velocity stats appear to be the same as the Sherman 75mm M3, but in practice the round feels slower and worse-?

2

If it helps I’ve noticed a major disconnect between the rounds like in game appearance and where the round actually is. Just several times I’ve hit tanks well before my round visually hits them and vice versa.