You could say it is "horribly beautiful"
I have not fully tested it, because I had some problems to solve. It is low pressure, (about 60 psi), so as not to deform the 5.5 mm lead spherical ammunition, which is what triggers and which are recovered.
It works in semiautomatic and automatic mode. In automatic mode it expels the 45 ammunition that the magazine has, in 2 seconds, or less, since only the ammunition moves, from the charger to the firing tube being the continuous firing air. The system is like a bottle machine gun. For this reason it spends a lot of air. It is to shoot at close range, so this is not a problem because it shoots connected to the compressor. It is built in thin fiberglass. I have manufactured the silencer, to have that aesthetic view that I like.It has a trigger switch and can fire one at a time.
When I finish it, I'm going to film the test. I leave some pictures of how it looks in the present.
It works pretty well. regards 
