I would suggest you pull the bullet from a few of these rounds and weigh the powder. My guess is that the charge may be a little different from that indicated.

I'm largely in the "if I didn't load it, I don't shoot it" camp. You just don't know what the person who loaded the rounds did or did not do. There have been people on this very forum who have said that they think reloading data is intentionally reduced for liability reasons, so it's okay to exceed published maximums by at least 10% - maybe even more. Would you really want to shoot that guy's reloads?

I have a good friend that I learned to reload with when we were teenagers. We developed our technique - including written reloading procedures and a checksheet that accompanies each batch - together. So, if the checksheet was with it, I'd shoot a box of his handloads and vice versa, but no one else.