For Sale Speargun - New Zealand made after Johnson model

I would be interested in examining it to see what stops the added barrel tube from twisting out and breaking the plastic handle and what stops the spear tail jumping the sear tooth as the modified gun must have added a sear box roof. In its original form all the trigger mechanism had to do was hold against the coil spring that fired the sliding bolt hammer onto the firing pin. I sent you a message, check the conversation envelope at the top of the page.

It is possible that this gun as modified never fired a shot because the SMG handle was designed to resist recoil from the breech when the gun fired using .22 Ramset cartridges rather than being under tension from rubber bands trying to pull the sear lever forwards in the gun. Rubber band load would exert a greater force on the sear lever than a coil spring propelling a sliding hammer.

Did you ever try a rubber power band on it to see if the trigger mechanism holds the shaft? A relatively long band would do as you don’t want too much load on it or it may shoot accidentally. Uncock the bands with your hands if you do try it, shooting spearguns on land is extremely dangerous as shafts can fly long distances, bounce off solid objects and end up anywhere. They can even penetrate car doors as a shaft is much heavier than a bullet even though much slower through the air. Spearguns are made to shoot through water, a much denser medium than air.

I have one of these speaguns as well. SMG but set up as a band gun. I'm currently finishing stripping and rebuilding it so I can get some photos for you @popgun pete of the insides.

I can tell you now that SMG under its original Tapmatic Corporation owners never made that band gun, in fact just recently I found my correspondence with Valerie Johnson which I will add to the SMG page. More likely it was a way to work away the stock of spare parts when the legal shutters came down on firearms adapted as underwater weapons. As I reported previously the only reason Tapmatic could sell the guns was under dispensation from the Tobacco, Alcohol and whatever departments (I cannot remember the exact name) was that it could not chamber regular ammunition. That technical nicety meant that the SMG escaped classification as a firearm in the USA. But no other jurisdictions would buy that argument and promptly slapped a ban on the SMG spearguns. That simultaneously scuppered my own ramset powered spear pistol and I had to cut it up. The only thing left is the trigger mechanism I made seen here.

The minimal band draw as shown before makes the band gun conversion a weaker weapon than it should be. Chop away too much of the plastic to increase the draw length and the gun may fold up as it was never designed for being under bending tension.

More here; https://forums.deeperblue.com/threads/johnson-submarine-gun-smg-cartridge-powered.116501/