Gippeto wrote:I swear...anything marked "Crosman" is laced with something...things are addictive.

I have no problem believing that! I actually have two MK1s

an older one in firing condition and a mostly complete bag of parts slated for Rugerification.
A great many folks take rough MK1's and fit longer/better barrels....the ubiquitous "LD" configuration....guilty of this myself. Cut down and fit a barrel from an HW100...still need to test it. Tensioned barrels inside a full diameter shroud look pretty sweet too.
This is more or less the plan, since it's .22 though it's on the back burner since I'm more enamored with bigger bores at the moment.
Believe I've seen that grenade cartridge posted before, still like the idea. Have not seen one in person, but seem to trigger very easily in the couple videos I've watched. Seeing it, and more so your version is sparking ideas....I see an afternoon with CAD coming up.
Note that there are two major variations, some with a central chamber in the "shell" portion (you can tell because the fill valve is on the nose) and others with a chamber in the "cartridge" portion (fill valve in the base). In the latter, the piston is somewhat balanced out so it's relatively easy to actuate even at CO2 pressures. Indeed in airsoft grenade launchers, you generally don't have a spring-loaded firing pin, the trigger just pushes directly on the base of the cartridge. I might have a few in the scrap box if you want to mess around.
Relying on momentum/inertia of components to delay ejection....looks like cart will start firing before it fully seats....API blow back concept??
I admit I'm curious to see how well it works in this case.
Herr Reinhold Becker would back me up
If it works for a 20mm cannon it should work for a pneumatic cartridge, right?
Going to use a spring to reset the spool, or reduce the opening to the back "store" some pressure during the shot cycle and use that to do the job?
I was thinking of resetting it manually, any form of automatic reset is going to increase the force needed to open it anyway.
I still have my reservations about the design in terms of friction, the bigger the o-ring then the bigger the force needed to move it and it's proportional to the pressure. A paintball slide check for example at 850 psi is pretty stiff and I want to go well beyond that. Maybe a smaller diameter ported tube like the
Magnum Air Cartridge is a better idea.
hectmarr wrote:I think that the percussion system moves the entire cartridge against the barrel that is fixed in relation to the body of the weapon. Where it is loaded, it is fired.
This design is basically what was
patented by Michael Saxby.
I think it's fine for lower pressures in the 150 psi region but the force holding the valve shut is proportional to the pressure in the chamber so for high pressures it would need a very strong hammer spring.