Crossman Stinger Shotgun
I have one and the TM version. The crossman works well but be warned that it will take a toll on your arms when pumping it. I'm a big guy and it gives my left arm a good workout compared to my TM M3 Shorty. Also note that you can buy two kinds of shells for it. There are the TM ones and a different brand with several different colours of shell. It will work with both but much better with the latter because the lip on the back of the shell is slightly larger. Better for loading and unloading.
It hits hard and accurate with .2s but since the real are short range, it might be interesting to test it with something in a .3 plus.