Certainly using standardized equipment; Rifles, optic, correct height mount, ammunition lessens the effects of the inherent downsides of a BDC system, but it’s still present. Change any of the following and suddenly your BDC is off, often by a surprising/significant amount. Elevation, temperature, pressure, different ammunition, different height optic mounts than what the BDC was calibrated to at the factory etc.
The Marine Corps Trijicon RCO/SDO, M16A4, M4, M4A1, and M27 are a perfect example of this.
When my Battalion switched to Mk318 ammunition our BDC no longer worked accurately.
We reserved so the 300M mark was POA/POI, flew to a different elevation, BDC was off,
had guys get issued Brit Radway Green Ball, the BDC was off,
had to use M4 marked optics on a 16A4, the BDC was off.
Use an SDO on a 249, BDC was off.
Change in temperature from rainy season in Helmand to the scorching temps in August, BDC was off.
And once it’s off, it’s a guessing game, trying to figure out which hold to use at what distance.
For there is one God, and one mediator between God and men, the man Christ Jesus.
1 Timothy 2:5