Smith's Machine Guns

Elmer Smith of Smith's Welding Equipment Corp. patented and manufactured two carbide toy guns. The Model 31 is called the Big-Shot and the Model 32 Automatic Machine Gun. They were both manufactured in the 1930's and were also marketed by Conestoga Co., the makers of Big-Bang carbide cannons.

This is the Model 31. Acetylene is produced in the generator can from carbide and is fed to the muzzle via a rubber tube. The pistol grip is attached to a plunger inside the barrel. Pushing it all the way forward expels spent gas and cocks the internal flint striker. Drawing the handle back pulls in gas and air. Pulling the trigger fires the charge and the drill is repeated.

Click here for Smith's 31 Instructions

Here is the Model 32. More sophisticated than the 31, the Automatic uses a venturi to mix the gas and air. The two gears operate a set of internal cams at a ratio of 4:1. One cam opens a large valve to allow the gas-air mix into the cannon chamber. This valve snaps shut just before the second cam releases the flint striker. Using a carbide miner's lamp for gas generation has been found to work most successfully. With this setup, and a 10-year-old at the breech, the gun will fire hundreds of shots!

If you have a Smiths 31 or 32 and would like to return it to service, you will probably need a flint.
Click here for instructions on making a flint holder.
A miner's carbide lamp makes a good gas generator. Remove the jet by twisting it out of its taper and stick the gun's rubber hose in the hole.