Geo. Ive seen those videos you're referring to. I will give them credit, it does quiet them down to the same report as a .22lr. Pretty impressive and not considered a suppressor by the ATF.

I have also seen some modern card shoot guns with very long barrels.
The gun I have, was built in the 1890's(?) and I would assume it to be a light, long range duck gun...but that's just my educated guess.