That looks like it has some mechanics I'm interested in. Could anyone post the internals or sell me one for cheap?
Thanks.
You should feel privileged FH. I've NEVER opened a gun in my life as I'm only interested in my guns being in one piece and functional. As a collector, I have no need to ever open up a gun and look inside or to monkey around with the internals, but I made this one exception.

I have some idea as to what I am looking at inside of this gun. The barrel rotating cylinder above the plunger looks just like the one that you can see in the Fast Blast, but a little more intricate. The spring is impressive, but the range is kind of lame. There is a gear system under each of the barrel assemblies that causes the rotation of them.
As for how comfortable it is to fire, surprisingly, it is quite good. It is designed to be fired by either holding the grip up or down, hence it's name the "Over Under", but it is much more comfortable to just hold it like a normal gun would be held. You don't get the accuracy issues that you would get from the Fast Blast due to the fact that you're not expanding the whole length of the gun to fire and it fires on the back pull, not the forward thrust, like the FB.
They also make a ballgun with similar design specs as well as a missile launcher, but I haven't seen the launcher to see if it spring-powered or just a ramrod construct.