I seriously doubt that will fly for a private citizen. Once again, who's gonna know as long as it's never transferred? But, being a consumer and claiming it was a pistol first, with that fact not being established or of record, you could be on thin ice.
You have a cellular phone? Just take a picture. Yes that is how it works. Some states prohibit this but the fed said it is ok. Granted give them two seconds and they will change their minds. Also burden of proof is on he state not you.