It’s nothing against you, of course! Every gun buyer should operate on the premise of buying the gun not the story.
I used to collect antique woodworking tools and it was always every collectors goal to find a nice old Stanley plane still new in the box. Read a report once of a guy that found an apparently unused one and decided to start using it only to find out it was a piece of junk. So in reality it was probably used ONCE found to be a lemon and stuck back in a box. Nice to look at, pitiful to use.
With the rifle being THAT nice and unwrapped, maybe a potential buyer would think the same thing of it. You’d probably be better off saying “I only fired it 20 times and here’s a couple targets.”