For a weird and wacky weapon that (amazingly) I don't think Paul has on his site, the Croatian
Kresimir Hand Grenade Launcher. No, "Hand Grenade Launcher" is not a typo.
Developed during the breakup of Yugoslavia, it launches Yugoslavian M50 hand grenades, which are percussion-primed high explosive fragmentation grenades. They're propelled by blank AK rounds. Both magazines (grenade and blank) hold 5 rounds.
The system has a two-striker system where the first striker hits the percussion fuze on the grenade, starting a 5-second burn, and the second sets off the blank to launch the grenade. Hopefully. There have been no reports of failure to launch. Ahem. It sure seems from the demonstration that it would be possible to delay pulling the trigger far enough for the second striker to activate if you wanted to use up some of the time on the fuze before launching the grenade. If you're bold. Or desperate. Or nuts.
Details on the M50 are sparse, but the related M52 grenade is claimed to have a 15 meter effective radius. The sights are marked to 500 meters, but I have no idea how optimistic that might be.
This is both the right time frame and the right kind of crazy for a T2K campaign.