I'm been on ASM for quite some time and I'm sticking with system supercore and Prometheus hard which are my go to pistons of choice for replacement, upgrade. I haven't replaced the supercore yet (2 years), and the Prometheus hard I just replaced after the pick up lug broke (3 years).

Airsoft Surgeon Stage 6 spring, for hardball games, and for my personal experimentation. Their is a small group of hardball players in my area and we play at those velocities on a semi regular basis. Unfortunately, this year 5 of our group are going to be away on exercise or contracts for the summer.

The piston SHS piston was this one:

Yes my AoE was adjusted.

Ahh, I understand. The pickup of that m230 spring is way to hard for that piston, that model. The only thing that is holding the metal rack from ripping through the piston is a small peace of polycarbonate connected to the piston. I have had the best results with the 7 steel tooth pistons, they have the best design in the piston industry. The thick piston combined with the rails that run along the piston teeth to re enforce it play a huge role on the piston strength. they share the same design as the supercore and the prometheus, but is quite a bit cheaper

7 metal teeth is WAY more than you need below 470fps.
I'm not saying those pistons are BAD, because the prometheus and system supercore pistons are undoubtedly the best in the industry. But if it HAS 7 metal teeth, it should absolutely be able to handle 650fps no problem.
Up to 470fps, you should only need 3 metal teeth. Polycarbonate is an incredibly tough material when processed properly.

From the other stuff I've seen made by SHS, you couldn't pay me to use one of their pistons lol