One of the rarest Big-Bangs, about only a dozen G-Guns are know to exist. This is quite a substantial 'non-gun'.
From its looks alone, one could probably hold up a bank!
Made from iron, steel, brass and aluminum,
the only non-metal parts are the rubber gaskets at each end of the water chamber.
Only two print references to the G-Gun were found during my reasearch. Both were in 1936.
Joseph Gombotz said it was intended to be used for training hunting dogs.
The cost of carbide being much less than shotgun blanks, was probably an attractive selling point.
The awkward problem of charging, waiting and then not waiting too long,
would have been a problem that cancelled out any cost savings.
No other print advertising for the 21GG is seen after 1936,
so it is assumed that it was discontinued due to the high cost of manufacture and lack of sales.

The bolt/charger/trigger-sparker assembly is quite complex and added to the cost of the G-Gun.
However, it cost only $0.75 more than the 15FC.

All known G-Guns have the two ball front rest.
None are known to have the triangular front rest as shown on the box.
This is not to say that none exist, as it is a simple part and could have been changed early in production if the triangle part proved to be troublesome.