Only once have I had an issue with a sold gun...4 months after getting it, the purchaser got back to me about issues with the gun. I paid for it's return with total refund and the rifle came back...with no trigger on it, and plenty of evidence it fired left in the barrel! I've also recently received a rifle that the owner neglected to mention he'd monkey filed the rear sight (off on both axis). Their response to inquiry regarding it was "as far as I'm concerned the deal is done". There are no absolutes in sales online.
In this case (resisting temptation to bash a 10/22), the rifle has been more than just fired. Swapping stocks, adding optics, removing optics etc...any of those events could affect the current owners ability to group. What to do now depends more on you than the gun itself. Put everything to date on the personal scales, and see which way they tip.