This is very cool, but I worry it’s going to prompt ATF to reclassify the Saiga shotguns as destructive devices. Generally speaking, anything with a barrel diameter over one-half inch is considered a destructive device. Shotguns are regulated under 27 CFR § 479.11:
any type of weapon by whatever name known which will, or which may be readily converted to, expel a projectile by the action of an explosive or other propellant, the barrel or barrels of which have a bore of more than one-half inch in diameter, except a shotgun or shotgun shell which the Director finds is generally recognized as particularly suitable for sporting purposes.
So all it takes is ATF to make a ruling and everyone who owns one either has to register it, or become an instant felon. There are a lot of Saiga’s out there.