Ever since patch .12.12 came out last december, and with it bullet trajectory changes; I've noticed a pretty bad bug with all scopes / bullets in the game pertaining to bullet drop when compared to the official bullet drop trajectories provided by BSG.
TLDR:
The graphs provided by BSG state that the most commonly used rounds 5.56x45 and 7.62x39 would have "positive" bullet drop for around the first 100m when zero'd to 100m
This is simply NOT the case - the exact opposite happens. The bullets drop within the first 100m.