BE VERY CAREFUL shipping with USPS right now, as they appear to be having a lot more problems during the COVID crisis. I purchased a gun from a gold member here, and the USPS completely lost it for about two months, told us it was just gone, and then it showed up out of the blue about 2 months after it was shipped. It was a super stressful experience, and the tracking simply sucked. IF you ship USPS, make sure you purchase the insurance for the full amount, otherwise the "tracking" you thought you paid for is absolutely worthless. They will tell you it went to facility X along the way a month ago, but they have no idea what happened to your missing gun after that. UPS and FedEx at least have decent tracking.
And be ready to justify the value of what you're sending in case you have to file a claim.