This is interesting...
I think it would be cool to see something like that reintroduced. It would be just a barrel replacement and probably not compatible with semi-autos.
However the fact that it uses standard .22LR ammo yet produces projectile of equal weight, better BC and higher velocity is very cool.
Imagine a Ruger American bolt .22 using this. What a cool little varmint gun with cheap ammo that would be.
TED