I honestly have no idea what it would take to successfully take a drone down. Some of them are so fast moving, unless it was coming straight on at you in a dive, I don't think you could hit them, let alone disable it. The horizontal/ windage lead would be ridiculous.
Having said that, I believe a 3.5" shell with the the heaviest payload containing the most pellets would give one the best chance against one. Bismuth and or Tungsten loads?
This is Federal flight control, but the shot cup may actually be a negative when trying to clip 100 mph drones out of the air? Perhaps something that spreads better?
https://www.federalpremium.com/shotshell/heavyweight-tss/11-PTSSX191F+9.html
These damn shells are almost as expensive as the bloody drones!? $100 Usd for 5 shells!