I'm a newb so perhaps this is a stupid question, but what exactly is the general concept of operation for the AirForce Condor? They advertise 1250 fps out of a precharged design (which I interpret as a non-piston design). I'm curious how this is done. ....Or is my intepretation incorrect and it's really just a pneumatically driven piston design?

The stock is a tank of pre-compressed air.
Kind of like a CO2 rifle but with high pressure air.

http://www.airguns.net/airtypes.html

Cheers,
Rich