The B&T GL06 (Grenade Launcher 2006) was developed in response to a French tender for a riot-control less-lethal weapon in 2006. B&T had actually already been working on a less-lethal projectile system, which they call SIR (Safe Impact Round). It is a rubber projectile with a hard plastic base and driving band, fired from a hard plastic case using a 9mm blank cartridge. What makes this ammunition noteworthy is that it is reloadable – projectiles fired in training can be gathered up and reloaded into their original cases, dramatically reducing ammunition cost (or conversely, allowing agencies to do a lot more training on the same ammunition budget).
The launcher is very simple, just a break-open single barrel system. There is no extractor or ejector; empty cases are just plucked out by hand (the plastic case does not expand when fired). It uses a heavy double action trigger licensed from H&K’s under barrel grenade launcher, and it is capable of firing 40mm high-low rounds (M79 type ammunition). It won the French tender it was designed for, and has been picked up by a number of other law enforcement and military agencies since.
Maybe it would harm the PR perception of non-lethal, but put a steel barrel in and it would be a great launcher for all 40mm rounds. Hopefully the rest of the frame would be able to hold up to higher pressure propellants.
Just offer it as a military model, and you’d sell a ton of them. These things shoot really well, and no under-barrel launcher can even compete. I’m just not sure that the wear on the current barrel would be a deal breaker.