This new system by Beretta just proves again that there’s seldom anything really new. In September 1971, MBA submitted a proposal to the U.S. Army to do the same thing Beretta has done, but by modifying an M-79 40mm grenade launcher. MBA had previously submitted a 40mm Stun-Bag less-lethal cartridge to be used in the M-79 and M-203 for riot control.

One of the unresolved issues with MBA’s Stun-Bag cartridge was that there had to be several different power-level variations to deal with rioters at different ranges, the same issue Beretta is dealing with. If a “Long Range,” e.g., high power, round was used at a close range, it could be lethal.
MBA’s “Graded Lethality Weapon” was proposed to be the solution, where one power level cartridge could be used at multiple ranges by venting propellant gasses by various amounts. However, MBA’s modification was somewhat crude compared to Beretta’s because the shooter using the MBA device had to visually estimate the range and manually turn a dial to match. The Army, in its reply to MBA, stated that at typical ranges of 200 feet, tests showed that human estimations of range were normally about 25% off. Beretta’s system is much more precise, but of course Beretta’s technology (ghost ring target bracketing) was not available to MBA in 1971. Still, MBA had the right idea.
There will be more details of the MBA system in my book’s supplemental chapter 28, in work now.