Although I can't really comment, it does look like it is not made out of aluminum likes the others.
Regarding the machining/design of all the pistons, you're absolutely right regarding the oring groves. Much to wide, and I can't see any reason for it to be designed that way. Narrower grove = less fragile, for sure.
Another thing I always wonder why they didn't do was anodizing the al pistons. With more suitable narrower oring groves and standard hard ano I would think the piston would function my better, namely keeping tolerances tighter.
That also goes for the internal reg piston. It, even more than the main piston, absolutely needs the tightest possible tolerances. Anodizing it could, if designed right (and having its housing's inside ano'd as well), provide a seriously positive boost in performance. And in so making it unnecessary for those of us who have had to using an inline reg or something to keep the internal reg from spiking.
And wouldn't ss work better than brass? I'm now saying I wouldn't be interested in trying a brass piston, or ti or whatever (but no cf or composite thank you), but would someone explain to me why they favor brass over ss or even ano'd or un-ano'd al? If it is just a case of favoring all things brass, I totally understand that. In some ways, especially when it comes to the bodies or exterior of guns, I'm the same way. But speaking in terms of pure performance, what makes a brass piston better than a ss (or al) version?
IMHO I preferred the piston that have threaded heads and set screw or use a screw to connect the head to the piston shaft. For some reason I was never a fan of the V1 design or whatever you were referring to in woouulf's post with all those pictures.
Last edited by toymachine; 11-17-2012 at 09:33 PM.