Grab-a-gun and CDNN are both places where you may find batches of guns / parts that were produced some time ago but sat in a distributor unsold for years. I call them the "Tuesday Morning" of the retail gun world.

But the date you purchase a gun "new" is the start of the warranty for the manufacturer.

I bought a "new" Ruger Single Six that turned out to be several years old, enough so that it needed new springs to replace a couple of rust bunnies.