Feinwerkbau Sport, the HW35, BSA Airsporter and Webley Mk III, and yes, even the Relum Tornado, I had or used them all. The tornado had a double spring, just cleaned out the old mans shed and binned a few of the springs. The tornado was a horrible beast of a gun. The airsporters and mercury were excellent value for money with plenty of power. Still have the webley and FWB.