How bizarre is this?

[Benelli B76]

That is an odd looking thing and I've looked at the pics and tried to work out something that would be practical or what it would be if I had the skills to make something like that. As I know very little about Co2 or pumpers it will be a bit of a wild guess.
How about a single stroke pumper with an automatic tap and the knob at the back cocks the trigger?
My thinking is that you put a pellet into the open tap, cock the guin once, which turns the tap into the closed position (a bit like a mk1/m2 Airsporter in reverse), then you pull the knob at the back of the cylinder to cock the trigger-------------BUT I cannot work out how the tap would go back to the open position without some sort of sprung thing. The other idea is that the knob at the back turns the tap ---------------1 pump charges the gun and sets the trigger and then you pull/push the knob at the back of the cylinder to turn the tap.
I'd love to know how it works.

No ways one pump would have any power at all, this would take a heck of a load of pumps to charge with the short stroke it has. Most inline pumpers have quite a long stroke.The tap is simply operated with either of the two thin serrated wheels on either side of it.
Studying it again I can't see how you develop enough pressure with the small volume of air in the pump to compress it enough to open the reservoir valve. Normally you need a high starting volume to compress down to high pressure.

Baz

[duomatic410]

Interesting, but looks like it's a pump up going by the damage to the slide, the forend is at half pump position. Perhaps it's one you pump up then top up after each ️shot?. Can't be very powerful, looks like the butt has been used as a priest.😊has that butt been cut length ways?....

[duomatic410]

Could it be a bulk fill co2 from the back? With a pump system in case you ran out? The rack cocking the gun.
It's certainly an interesting subject.

[averageplinker]

The butt looks like it was made from 2 planks glued together to get the desired thickness but the glue is now failing/has failed!

[DT Fletcher]

Went pretty cheap at $356.

I'm reasonably sure that this is a pump up pneumatic; the hinge at the front of the forearm speaks to that. Really hard to say much more without seeing the forearm lowered.

[Benelli B76]

Went pretty cheap at $356.

I'm reasonably sure that this is a pump up pneumatic; the hinge at the front of the forearm speaks to that. Really hard to say much more without seeing the forearm lowered.

Then the photo doesn't make sense. That means the pump arm metal goes all the way back to the trigger unit and seems to go under the it. If the whole pump lever goes back right to the stock, why is the pump handle so far forward (much less leverage). Also there is a small bracket with two screws which seems to be locking the "lever" to the tube above

Baz

[DT Fletcher]

Then the photo doesn't make sense. That means the pump arm metal goes all the way back to the trigger unit and seems to go under the it. If the whole pump lever goes back right to the stock, why is the pump handle so far forward (much less leverage). Also there is a small bracket with two screws which seems to be locking the "lever" to the tube above

Baz

I see the same things but how else to explain the large pivot at the front end of the forearm? I would assume that the forearm wood covers up the area where the pump lever breaks from the body of the gun.