Quote Originally Posted by springboy View Post
I liked the early silver/blue streaks that had the back up shot capabillty you got 2 shots for one charge,although if I remember the second shot wasn't as powerfull as the first.
To get the Sheridan, Benjamin and Setra under 12ftlb's the importers cut the hammer springs down so that the gun became a two shot per pumping gun.
After the first shot you had to put 2 or 3 pumps into the gun to bring the second shot back up to 12ftlb's, the pump sequence of some guns were published in Airgunworld Gun tests.
John Bowkett in his experiments found that a fully pumped Benjamin would give one shot at 18ftlb's when all the air was dumped, or 3 shots at 12ftlb's when the valve was used as a reservoir and a shorter hammer spring used.
This idea is now being toted in the States as the ACV (Air Conserving Valve) in conjunction with a HDD (Hammer Debounce Device), basically someone is trying to take credit for John's experiments from 20 years ago.


All the best Mick