You will need: a Buzz Bee Mega Missile, a standard $5-6 ball pump, a 3/4x1/2" pvc reducing bushing, epoxy putty, CA glue, and goop.
Internals:

Cut the tank down like so, removing the stock barrel and pump tube.

Fill the stub of the pump tube with epoxy putty, making sure you don't foul the original check valve. Then press the end of the new pump into the soft epoxy putty, making a fairly exact impression.

Coat the end of the pump with CA glue (I prefer Loc-Tite). Then press it into the end of the tank.
When it's dry, go ahead and goop around the joint. (I later added a ring of epoxy putty, just for excessiveness' sake.)

Glue on your bushing. I used a probably lethal combination of goop and CA glue.

You'll need to dremel this out, so that the ball pump fits. It ain't a subtle process; just keep removing plastic until it fits in there tightly. You should be able to keep all 3 screws if you're careful.


Dremel the front out for the bushing.

And you're done. However, I wanted more. Due to the shape of the shell, a pvc turnaround has to fit sideways.

I wanted to take advantage of this. So I made a triple speedloader.

And remember that small grip? I cut a couple of lengths of 3/8" PEX, taped 'em together, then taped it to the handle. Primitive, but highly effective. You could get as sophisticated as you want with this, of course.


Family photo:


Now, you may be thinking: "Rork, isn't replacing the stock pump with a ballpump just like plugging it?" The answer is no. The large face of the ball pump prevents building up too much pressure; you need some muscle to pump this. 1 pump fills it up nicely. And yes, you can do this same mod to a BBBB or LBB, with great results.