The idea for this started with that whole SA-8 fiasco some time ago. I saw a market flooded with "useless" sa-8s that everyone was trying to sell on the cheap. So I decided to buy one, cut out everything except the part that accepts the magazines, and mount it onto a side-stock-class phantom breech.
stiffi freak barrel
low pressure springing
built in palmers reg valve
16cc hpa tank (yeah, I was surprised to find one of these too)
Basic construction process:
Begin with a side SC breech. Dremel out the feed port to fit first strike rounds. Take a phantom sight rail, cut off about an inch and a half to put in front of the feed port. Sand off the anno on the breech and under the sight rail, then epoxy them together. Grind off the top of the sight rail until it is a flat surface. (This flat surface is easier to affix to the tiberius parts than a tube would have been.
Take apart the sa-8, and remove all the internals, leaving just the body and grip. Sand off the anno around the aluminum body area where it meets the plastic grip. Sand the corresponding grip area so it is rough. Epoxy them together and then reassemble the screws holding the whole thing together until the epoxy dries. (This is important, because we will cut off the portions that screw together later, so we need to epoxy now while it is lined up correctly for the magazine spring release).
Cut off the bottom of the grip and everything around the junction, then grind down the top until it is flat. Line it up with the phantom breech and epoxy them together.
The marker works as expected, with a few caveats. The first strike rounds can load and fire (and aim like a charm). However there are two current issues. First, there's a bit of space between the magazine and the breech, and second the breech of a phantom is a bit larger on the inside than is optimal for handling first strike rounds. As a result, when you pump, the round behind the one being loaded will be rotated 90 degrees up by the pump action, then it will be rotated back forward when it is its own turn to be loaded. This is fine, except you have to have a very smooth and gentle pump stroke otherwise you risk cutting the "fins" on the round. Another problem is that the last round in the clip fails to be rotated properly because there is nothing pushing it down, this would probably be fixed after I grind off some more material to place the magazine closer to the breech so its internal spring will continue to press the round down.
Also, I did not realize the spring for the magazine release is embedded in the material of the grip; cutting off so much of it removed the springiness, so the release has to be manually switched when you load a new mag. I may try to find another sa-8 to redo that and leave another half inch of the grip intact.
I would like very much if one of the many talented airsmiths would like to build a more professional run of these.....
This post has been edited by MuKen: 25 August 2010 - 12:55 PM