This piston works. It's fairly light, and will last for a good time in a low-stress (20ish rps) set up. For me it lasted about 30K rounds. Then the plastic around the metal tooth snapped, and the metal tooth somehow ended up in my spring, which then didn't compress and my gears shredded the thing.
Soft so at least it's easy to Swiss-Cheese
Rating: [3 of 5 Stars!]