I bought my trap gun from a site called trapshooters. We didn’t know each other and I’m now looking to upgrade again. That means I’ll list my gun there and buy another one there. I don’t see any issues with that, I don’t think its anyones business either
And I think you should be able to buy and sell like that - it should be your own choice.
All of the guns I own were bought from a dealer...so I’m ‘in the system’ already. And if any of my guns were ever used in a crime, the serial number would bring the police to my doorstep. So, my choice would be to use a dealer, to avoid that hassle.
Now if I bought a gun online, outside of ‘the system’, I wouldn’t be too worried about turning around and selling it online.