Spike’s has done it again. Blowing our minds with this video clip they just posted. Due to the complexity of the physics of moving water when shooting under water most firearms only fire one round. Spike’s fired a 9mm underwater machine gun successfully in full auto!
According to a Spike’s Tactical Representative, that person shooting the underwater machinegun is the owner of Spike’s Tactical. He is apparently an experienced and licensed SCUBA expert. One day he decided to task his employees to solve the problem of how to make a machine gun work under water.
Looking at the Spike’s Tactical video above you can see some modifications were made to the buffer tube. Water does not compress so when the buffer travels rearward it has to go somewhere, so they cut a slot for the water to squirt out.
Shooting guns underwater sounds simple. Go underwater and shoot a gun. Simple, right? Well if you want to gun to continue to cycle that is where the challenge arises. So far very few have been able to do it successfully. Russia came up with their APS rifle in the 70s.
This video explains how it works. Basically it fires a sort of hybrid spear/bolt using cartridges.
If you want a gun to keep shooting and function underwater, then you have to solve some serious physics problems. As Mark Watney said in The Martian “I’m going to have to science the shit out of this”.
According to my Spike’s contact, this gun has been heavily modified. Not just the buffer tube but the BCG, trigger, and barrel. They used a 9mm since it is direct blowback. Direct impingement would not work nor would a piston system since it still relies on gas.
Once Spike’s Tactical irons out the details they will be mass producing these guns. NFA rules apply.