How bizarre is this?

[le frelon]

Just to throw in a 'wobbly'..pcp, trombone slide thingy to cock/supply ammo stored in the tube above, think pumpy shotgun/Daisy bb multishot, Loading tap perhaps just open for cleaning/access? Whatever system it uses it does at least look to have seen some use.

Carl

[45flint]

I saw this but I thought it got a little too much? I saw Wells prototypes in the Bluebook. A experimental maker in the 1950s in California where this gun came from. He had similar forearms? If him it went cheap, but seemed too crude?

[--ped--]

looks to me that the large tube at the rear is a reservoir possibly co2 the slide cocks the hammer
can't see any reason for tube to be the size it is unless it's a reservoir or the guns a springer

[Benelli B76]

Yes, the knob at the back could be unscrewed to expose the bulk CO2 filler valve. The short slide action could cock the hammer, that would make it quite a pokey performing rifle.

Baz

[harry mac]

I'd say the slide opens and closes the tap, and the knob at the back cocks the valve hammer. Just a guess.