What the heck are these pistols???

[Multigunner]

https://www.ebay.com/itm/2-Vintage-Crosman-Arms-Air-Jet-Line-Gun-CO2-pistols-Model-101/264464187499?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D1%26asc%3D60037%26meid%3D7cd0bd801eb14d458f7e431dba2e6fa2%26pid%3D100005%26rk%3D1%26rkt%3D12%26sd%3D174031113528%26itm%3D264464187499%26pmt%3D1%26noa%3D0%26pg%3D2047675&_trksid=p2047675.c100005.m1851

Never heard of these

[BillK]

Not for sure about those pistols but the US Navy uses a CO2 rifle to shoot a line to a refueling ship at sea. Then pull a heavy line, attached to the light line,  across to secure the ships when refueling.

[CraigH]

I have not seen these - it is not is Fletcher's book.

[KevinP]

I have seen this... I believe, perhaps, it was made to
help electricians run line through conduit, ( maybe ) 

[Nvreloader]

Here is some info on that item,

the Crosman Jet-Line pistols that shoot carbon dioxide cylinders (they doesn't shoot from cylinders; they actually project  the cylinders themselves as projectiles to jet along in big electrical conduits to aid in pulling electrical wiring), and the Cap-Chur guns that are used to project tranquilizer darts into animals ranging from mad dogs to elephants and even human criminals.

Tia,
Don

[Nvreloader]

You can see the Co2 cylinders in this photo,
just off the end of the muzzle, 3 of them there..........

https://www.ebay.com/itm/ANTIQUE-CROSMAN-AIR-GUN-JET-LINE-MODEL-101/192895820855?hash=item2ce97ca437:g:V4EAAOSwXq5cYKBA

Tia,
Don

[Multigunner]

You can see the Co2 cylinders in this photo,
just off the end of the muzzle, 3 of them there..........

https://www.ebay.com/itm/ANTIQUE-CROSMAN-AIR-GUN-JET-LINE-MODEL-101/192895820855?hash=item2ce97ca437:g:V4EAAOSwXq5cYKBA

Tia,
Don

They appear to have a much broader mouth that standard Capsules. Probably necessary for more rapid release of the gas.

I've seen backyard rockets made with CO2 capsules as the motor, and those work surprisingly well.
I expect when pushing the spool of line down the conduit they in part use the conduit itself as the barrel to allow a longer impulse.

Years ago I had given some thought to a CO2 cane gun that could fire a heavy dart or arrow by piercing a capsule and using the full gas charge at once. I figured the gas escape would be too slow to build much velocity.

[Nvreloader]

MG

When they use the cylinder, there is a clip that snaps on the cylinder, the line is tied to this clip from the string cartridge,
then the cylinder is loaded into the barrel/holder and the string cartridge is loaded into the holder and tied off,
then the CO2 cylinder is fired which pulls the string from its cartridge during the travel of the Co2 cylinder thru the electrical conduit.

When the Co2 cylinder reaches it's target, the operator at the sending end cuts off the string,
and ties a stronger rope to the strings end to pull another rope which pulls electrical wiring thru the conduit etc.

Needless to say you don't want to be on the receiving end of that Co2 cylinder, as it will leave a mark etc.........

Now a days, they just use a vacuum and suck a parachute down thru the conduit, with a string tied to the parachute etc.

Tia,
Don