I finally got this little sucker finished after a few ups and downs during the build process.
It is an AGS-17 Plamya (flame) Automatic grenade launcher, which fires a 30mm round. I've made an Afghan guerilla to man the thing. As with so much Soviet kit it is used by many armies and guerilla groups around the world.
Here is a shot of the completed weapon and gunner.
I had some really solid photos and stats in books, and as usual found plenty of useful stuff online.
The weapon was built around a core of copper wire, and initially the tripod was affixed to the base. I couldn't talk Nic into casting the tripod and base as one piece, so ended up popping the completed tripod off the base (....tricky!) and got the Playma and it's tripod cast up, enabling me to work out a viable way of mating it to the base.
After plenty of fiddling about, all the pieces came together. I used one of the heads from my original Afghans but gave him a rhinoplasty. It's really satisfying now the Playma is done! This means that the suite of Soviet support weapons for the Eureka moderns is just about complete, plus I can add this weapon to other sets to round out their heavy support.