[context: comment in relation to the original title, which has been changed, listing the drones as using 40mm warheads. No negativity meant to the original poster, I was just trying to be more factually accurate.]
I believe those are PG-7VL warheads, which makes them 93mm.
The 40mm number comes from the fact that all RPG-7 rounds have 40mm bodies for their tubes. The warheads are usually over caliber of 40mm though, except for a few anti-personnel rounds.