>stage a suicide
>perhaps a robbery gone wrong
>maybe stage a drunk hit and run
>OR
>use an extremely oddball weapon which will be beyond conspicuous if the coroner does a thorough job
>gee, wonder what this very distinct puncture wound is

The HNNNGGGG pistol was always 50% schizo fantasy, 50% red herring to distract you from real and important shit. There are so many other ways to rub someone out with some plausible deniability that the exotic approach of this concept is completely unnecessary.
They literally do it all the time.

>>64244961
They definitely throw shit at the wall to see what sticks, that was going on even in the OSS days. I would not be surprised if this was something they actually got funded and tried to make happen, but then found the weapon's concept at odds with physics and/or practical application, thus they were fine with throwing it out as a red herring, it wasn't gonna be useful for anything else anyway.