I can't find them in the core book or Arsenal. so it looks like Traser rounds or capsule will have to suffice. Personally if I was gonna make a shotgun lay down real figure, I'd either go with an under barrel ares-s III super squirt modified to shoot napalm (making it a flame thrower without an ignition source.) or a Shiawase blaser so that you can cover someone with the "flammable chemical" and then hit them with a flare, explosive, EX explosive, to ignite. Otherwise you'd need to so a serious knowledge skill check or data search test to find plans to build them, then an Armorer test to make them yourself.