This was the first of the post-WW2 German recoilless (or recoil supressed) match rifles, and incorporated an ingenious small bore rear-facing piston in addition to the main forward-facing piston, which helped to cancel out recoil. It also had a sliding breech which opened behind the barrel, with an elaborate grooved ramp to assist with inserting a pellet directly into the breech. The sliding breech is now commonplace on fixed-barrel sporting air rifles.
Anschütz LG220 rear-facing recoil suppression piston
With thanks to Arnold for posting these pics on the American Vintage Airguns forum in 2008. He said at the time: "I have a couple of photos of the REAR piston on the Anschutz 220.
Here is a series with the rear piston and the guide springs in place, then one removed and finally with the mainspring partially installed.
The detailed machining and synthetic piston bearing is nice. There is a spring loaded button that keeps the rear piston from leaving the cocking slot and then the metal tab that protrudes through the piston and catches the piston rod from the front piston."