I have a Rem 700 that’s chambered in the 280 Ackley (it’s marked 280 Ack on the barrel). I have a Manson Go Gauge that’s dated 9/13 that will chamber freely bare and barely close with a piece of Scotch tape on the back (+.002”). With a set of calipers, the shoulder location on the Go Gauge is the same measurement that Nosler lists in it’s load book for its 280 Ackley (2.097”).

Does that mean this rifle is chambered to the Nosler 280 Ackley rather than the original Ackley? I was under the impression that Nosler’s version was shorter than the original and Nosler brass shouldn’t be used in older Ackley chambers.

Before the Saami standard, there was a large variation. I had a previous chambering that was shorter than the current version. Had to mill the bottom off the size die to even bump shoulders.

Could be yours just happens to match the current version