Yeah I heard about Bulldog 6 from STALKER, Well Josh I think it might suit the animation....I think M32 from Soldier Of Fortune payback will be a hard to do animation. I don't know is there any other game that have M32 in it....
Black Ops 2 has one, codenamed War machine i think. Either ways, i can get either of them if i want. Both from SoF:P and Bo2
There's one in Smod Redux and Outbreak that you could use?
I think the one you're refering to, is actually a shotgun skin for CSS. Which looked more like a grenadelauncher.
The A35 by DropdeadWARNING RUSSIAN WEBSITE INBOUND!I wanted to get the FPSbanana link, but sadly, the place is down momently.
It sadly isn't a M32, i will however guess that it is based off it. But the reload would be completely off for the M32 model, well unless certain modifications are made

My best bet would still be using the Stalker Bulldog animations, i know there is a complete set on FPSbanana that has CSS hands.