Isn't 2AZone the store that does single-shot conversions? Because every handgun (pistol, revolver, ...) has to be on the roster in California, except:
- Single action revolvers, which this isn't (no rotating cylinder)
- Single-shot pistols, which this isn't (has a tubular magazine and can fire multiple shots)
- Olympic pistols, which have their own list (no lever action has ever been used as an olympic pistol)
So it could be that the gun is converted to single-shot (for example by blocking the magazine or disabling the reload mechanism), sold as a single shot, and then converted back by the owner. That trick was popular for semi-auto pistols, and the legislature closed that loophole.