VFC Polycarbonate Piston — Full Steel Teeth

Pistons fail at the teeth. Strip one and you will usually find the polymer rack chewed where the sector gear bites hardest, and the harder the spring the sooner it happens. A full steel rack moves that failure point somewhere else.

The body stays polycarbonate, which keeps the mass down — a heavy piston costs you rate of fire and gives the spring more to accelerate. Steel where the load is, polymer where it is not, is the usual compromise and this is VFC’s version of it.

It is a VFC part so it is cut for VFC gearboxes first. Shim and test it like any piston swap rather than assuming it drops into a shell from another maker.

Specifications

Good to know before you buy

Full steel teeth suit heavier springs and higher rates of fire. On a stock-power gun a polymer rack is usually enough, so this is an upgrade with a purpose rather than a default choice.

Any piston change wants a correction angle check and a shim check afterwards. Swap it, then test fire before you put the shell back in a gun you care about.

Frequently asked questions

Which gearbox versions does it fit?
VFC do not state a version. It is a VFC part cut for VFC gearboxes, so treat anything else as needing a test fit.

Will full steel teeth wear my sector gear?
Steel on steel is harder on the gear than polymer is. Pair it with a steel sector gear and a correctly shimmed box and it is the standard high-stress setup.

Does it come with an O-ring or a piston head?
VFC list the piston and nothing beside it, so plan on reusing your head and O-ring.

What does it weigh?
No figure is published for the piston mass, so we are not putting one on it.