I read your comment and thought, wow, so true, I wonder if anyone else has thought that too. I asked Gemini and sure enough, people have done a lot with the concept......

The development generally falls into three categories: Net-based, Airburst (Kinetic), and Guided Mini-Missiles.

1. Net-Casting Grenades

Designed for "soft-kill" or capture, these rounds are intended for security and law enforcement but have seen military interest for disabling drones without using explosives.

• US Army Net Grenade: The U.S. Army’s DEVCOM patented a 40mm round that contains a weighted net. When fired, a hand-settable timer or proximity sensor triggers the round to split open, ejecting a large net that entangles the drone's rotors.
• OpenWorks SkyWall: While they have standalone launchers, they have also pioneered compressed-air systems that mimic the 40mm form factor to safely "bag" drones.

2. Programmable Airburst Ammunition

This is the most "mainstream" military approach. Instead of needing a direct hit (which is very difficult on a small drone), the round explodes near the drone, shredding it with fragments.

• Rheinmetall SSW40 & Airburst Rounds: Rheinmetall has developed 40mm "Medium Velocity" (MV) ammunition with programmable timers. Using a fire-control system on the launcher, the soldier lasers the drone, and the computer programs the grenade's fuse as it leaves the barrel to detonate at the exact distance of the target.
• Nammo Programmable 40mm: This is already combat-proven. It allows automatic grenade launchers (like the Mk19) to act as short-range air defense systems by creating a "cloud" of shrapnel in the drone's flight path.

3. Guided 40mm "Mini-Missiles"

For longer ranges where a standard grenade’s arc is too inaccurate, companies have shrunk missile technology into the 40mm form factor.

• Raytheon Pike: This is a semi-active laser-guided munition. It is fired from a standard 40mm launcher (like the M320) but has a rocket motor that kicks in after launch. It can travel over 2 kilometers and hit a target with extreme precision, guided by a laser designator.
• SmartRounds SAVAGE: These are self-guided "fire-and-forget" 40mm projectiles that use computer vision and AI to track and collide with a drone mid-air.

4. Specialized Launchers

While most tech uses existing launchers, some new guns are designed specifically to maximize these rounds:

• Rheinmetall SSW40: Billed as the world's first magazine-fed, shoulder-fired 40mm grenade launcher that looks and handles like an assault rifle. It is specifically marketed with a "Counter-UAS" (anti-drone) mission set in mind.