Oh..the Line-Gun is interesting. I believe it
uses CO2 cartridge to
carry a string..Got lots of string spools, no
cartridges. When you
cock it..and pull the trigger..a piston with a
spike on the end slams
forward into the center of a holder and
apparently pieces the ass end
of the CO2 cartridge..which is tied to the
bobbin of string and
launches the entire CO2 cartridge. Seems like
it would pinwheel
badly..but maybe the string acts as a tail...

The CO2 powered "string gun" is used to get a
string through electrical conduits so that a pull
rope can be pulled in. This is then used to pull
the cables through.

I nearly got my head torn off by one of those
things when I was working for an electrician in a
holiday job as a kid. We ran out of CO2 while
working in a helium plant. On of the helpful
operators on the plant volunteered to supply gas
off the column to drive it. I was given a small
plastic funnel and was told to use it to catch the
ball of string at the other end. I don't know how
much pressure they applied, but it was enough to
take the end out of the funnel! If my head had
been over the end of that conduit it would have
had a piece of string right through it.

Tom