William, I heard all that before and seen the drawing.
When Nosler and Sierra published the drawings in their manual for the 280AI before it was SAAMI spec and not sure how many rifles build with those chambers. What little I know about the Ackley's if I had one build back then I'd fireformed some brass and I think Nolser had those drawing in their manual #4 and #5. Long before Nolser came out with #6 it was known there was going to be changes as that manual came out 1 yr before 280AI became SAAMI spec. Manson was making reamers for that Nosler brass before it was SAAMI spec.
I would of assumed someone who purchase that brass would of checked that brass against their existing brass. I would of done it just see how good they match chamber see if they got shoulder sharp etc. I'm not saying it should be buyer beware and it's not first time this has happened and it's real hard for me to figure someone not hold those two cases together comparing them and looking at them.
As far as true Ackley that's always be debated for gunsmith. You have some won't set the barrel back and some argue headspace and I'm not sure if I was in the business I won't of done the same thing as Nosler did. I got 5 other Ackley's right and I had about another 12 build since the early 80's so I've had my mix of Ackley chambers most of them were good.