^ nope
here are a few ideas, although getting your hands on these might not be easy
You can try to mod one of these to make a mortar
http://www.redwolfairsoft.com/redwol...p?prodID=20411
http://www.redwolfairsoft.com/redwol...sp?prodID=9278
or if you are just looking for rounds these are what i had in mind
http://www.redwolfairsoft.com/redwol...sp?prodID=8839
http://www.redwolfairsoft.com/redwol...sp?prodID=8840
this would work great if you dont want an external powersource
http://www.redwolfairsoft.com/redwol...p?prodID=18607
aparrently it only needs to have the pin pushed in to launch, so you can fab up something to make it realistic, like so you just drop it down the barrell and it lets loose
if not i think going with a potato gun or external co2 tank is the best way to go, the hard part is to get shots consistant so you can actually calculate trajectories