Prometheus is one of the most famous Japanese brands for aftermarket airsoft upgrade parts. Prometheus have established a name for themselves by providing nothing but the best quality upgrades for a wide variety of airsoft gun types, and this piston is a fine example of that. The polymer body is very strong, and when combined with the 7 metal teeth it makes the perfect composition for an airsoft piston. The reason the back teeth have been kept polymer is so they can flex when, slightly, when the inertia of the gears connect with the piston teeth. The teeth near the front of the piston are reinforced with metal so they don't give at all as the gear teeth are letting go while the spring pushes the piston forward. Prometheus is the number one name for upgrades to many highly skilled airsmiths, and it's easy to see why.
The use of aftermarket airsoft parts is not an exact science. Some parts may require fitting even thought they were designed to fit without modification. Professional installation of upgrade parts is highly recommended.
2010-05-06 16:32:22 B. SNIFFEN verified buyer
For: Prometheus Hard Piston (Black)
This piston is nice. Beware though, it is too wide to fit in a VFC SCAR-H gearbox without modifying the piston. I had to shave out the groove between the rails on the piston to make it loose enough to slide. I also had to remove the second-to-last tooth to prevent pre-engagement.
Seems very durable
Requires modification to fit in a VFC SCAR-H gearbox.
2009-09-06 07:04:08 J. ARVAY
For: Prometheus Hard Piston (Black)
This piston recently was in two compression jams with an M130 due to a hop-up bucking refusing to let the BB pass. I heard the gear teeth make contact... in a bad way... with the piston teeth, and thought that I had at least several stripped piston teeth.
I opened up the gearbox, lo and behold there was only slight damage to one tooth. This piston must have turned God mode on at the last second.
For some reason though, this same piston did not hold up well in a KWA M4 (~390 FPS @22 RPS). It showed wear on 5 teeth after only ~3000 rounds. I'm guessing that since the KWA piston/gearbox are around .75mm to 1mm wider than a standard gearbox/piston, so the Prometheus piston was doing some moving around, and that contributed to the wear.
I have been running this piston with an M130 in a set-up capable of 20 RPS at 430 FPS, and the only damage it has seen has been from a compression jam, and it survived that with barely any damage.
-Relatively cheap. Most pistons capable of taking the stress this piston does cost ~$50.00. You can find this piston for as cheap as $32.00 in the states.
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