Sorry if I sounded "curt", was not my intention. You have my humblest apologies. English is not my "maternal tongue" and sometimes it is difficult to convey across a keyboard the precise frame of mind/spirit.
Having said that, I think Herb is right, that is why I did not answer to Herb; but to Curtis, and then just posting my opinions. When I see Theobens being sold for US$2,000 or Whiscombes for more than that, I cannot but wonder and be grateful that Mayer & Grammelspacher is still putting out very good guns for the money. Even if you take into account the exhorbitant prices we pay here in México. You are much better off in the US with its good and progressive import freedom.
Coming back to the subject, Yes, Herb is right and in more than one count:
1.- If you see the performance of the Webley pistols (BTW, Webley HAS built in the past Carbines on the same principles, look at top and bottom guns in this picture):
you can see that the performance is way out of proportion of the spring force and the swept volume. ¿Why? because of a thing called "airgun effect" in the ballistics world or "ram shock effect" in the hydraulic world.
Think about the times when you close your faucet very fast. There is a LOUD "THUNK" in the pipe. This is due to the Bernoulli's laws of continuity, where the energy of a moving fluid (water or air, it does not matter) tends to stay the same. These laws have a number of effects in airgunning, and devoting a few hours to think about them is probably the best investment an airgunner can do if he ever wants to understand the physics behind the sport he loves. But I digress: The airgun effect means that if the flow of air is going in one sense (in the webley pistols it is going backwards, towards the shooter), and then has to go forward, then the pressure spike in the compression chamber is TWICE the pressure spike than what you get in a normal compression chamber (for those of you that handle vectors, it is a reversal of the momentum of the piston, therefore the opposing pressure that produces that reversal of directions means doubling the magnitude of the opposing force). This means that there is more energy available to transmit to the pellet. So, therefore, MV is higher. So, by stacking the barrel on top of the compression chamber and then making the piston go backwards while the pellet goes forwards you actually imagined a more efficient mechanism. Efficiency being defined as the proportion between the energy you put into the spring, compared to the energy coming out in the pellet.
2.- IF the barrel went on top, then the barrel itself can act as cocking lever. No need to have a separate cocking underlever. This has been incorporated in a number of guns, but again, the most notable are the Webley's. This simplifies the mechanism and makes it easier to manufacture. It should mean that the barrel needs to be real stout, but that should be like that anyway, again, look at the Webleys and wonder how such a slim barrel can be so stiff.
3.- By making the piston go backwards, then the shock wave imparted to the shooter is more "conventional". Shooters will not miss the rear-thrusting recoil compared to firearms.
4.- Scopes can also be more "conventional" because there is no forward recoil. Sure there is the scope-killing vibrations, but not the reverse recoil.
So as you see my dear friend, though your imagination treads on trodden grounds, is well oriented and very sensible. As a matter of fact, I should have somewhere Valery's design for a pistol that works like this and that he has looked for someone to manufacture. At one point in time I even sent the design to M&G, to Herr Andre Wirth, when he was the Big Honcho over there. His answer was that the product line was rather complete and that they had other things in the works (this was when the 460 was in the design stage).
Anyway, hope I have clarified everything. Again, my humblest apologies to Curtis if I sounded too "sharp". It was not my intent.
Un Abrazo!
Héctor
