Basically, I wanted a tacticool/practicool blaster that worked well and was compact. My first attempt at a clip fed homemade, base of the Fal3 was good, but a little longer than I liked. Using the multiple orgasm as a platform, I was able to solve the size issue and make it much more comfortable.

here it is fully assembled. Specs are 250fps, 100ft range, 6" draw, 26" length, 16" barrel, HAMP-able. The main body is 1.5" PVC, the plunger tube is a +bow plunger tube, the inner tube is clear 1" PVC, and the barrel shroud is 1-1/4" thinwall PVC. Thinwall isn't necessary but it reduces the weight. The rest of the tubes pretty much are. The catch was sized down to fit inside 1" PVC. I used a circle template thing so I don't have templates. 3/4" set screws work better than panheads.

Here is the shroud, held on by straps of styrene (I used the thickest plastic sign I could find at home depot). It stays on perfectly with no wiggle via 4 screws. This was a step up from the hot glue and duct tape i originally used.
http://s1232.photobu...html?sort=3&o=2
Here you can see the barrel and breech. The part that actuates the breech slides over the barrel. It's 1/2" PVC, and its crucial to find loose fitting PVC for it to work well. My breech was made specifically for PakD clips/Xplorer clips (load in the middle of the mag).

Here is what the pusher looks like uninstalled. It's 1/8" steel rod bent to slide around the sides of the barrel/breech for maximum leverage of the pusher.

This is the part that gets pushed on by the pump/inner tube/catch tube/etc. It took me a while to get it right, but in the end I found that countersinking a 6-32 screw and using spacers and a lock nut worked the best. Ive fired it/dry fired it multiple times with no wiggle on it at all. If I wanted to i could secure it further with epoxy but that's not necessary.

countersunk screw. 3/4" length

This is the slot that was made through the inner tube and body. It's about a 3" slot when lined up perfectly. At this point, the pump is about at half prime

Pump forward, breech closed

pump back, blaster primed, breech open.

Here's the breech, with a lip to scoop up darts. The clip sits right up against the elbow and tee. The length of cpvc that makes up the breech was drilled out with a 1/2 spade bit until the pusher slid easily through the back, but with some friction closer to the Tee. A better method would be to use a stub of 17/32 brass and use sizes up to 5/8" brass. This is what I will be doing with the next one. The seal isn't perfect, but it doesn't have to be.

The pusher goes back just enough to allow the dart to move up, with a few MM of leway. The pusher stays within the cpvc to help guide it back in place.

Closed, dart loaded. Again the seal isn't perfect, but it works well enough.
With all that said, there are a few cons to clips. It's definitely a different play style from hoppers. While i could still rush well with it, I couldn't reload on the fly which made it hard to stand my ground after a rush. It also means you're (more) vulnerable during the reload. Reloading clips in genenral is also annoying, as well as having to carry them. I never needed more than 2 a round, but that was a small (10 players) war.
Questions/comments/flames are welcome. I'm sure I didn't cover everything.
Also thanks to koree who sparked my interest with the clips, and doing the initial chrony readings on the blaster.