I came across this on the Arnies Airsoft site http://www4.ocn.ne.jp/~elfin712/Lightning.htm
nope, and those 27mm shells are hard to find, i was already gonna try and make one like a year ago with them but thier too rare and expensive.
Man just use the standard 40mm grenades and some PVC pipe. BAM! Custom gun and you could make millions.
HeadOnTactical.com
hudson makes a side by side double barrel shottie