Looking for ideas from the HuntWA smart guy experts as to what this cartridge is.
Top is 30-06 full length resized
Bottom is .300 RUM full length resized
Middle is in a 30-06 parent case. The bullet is .308 diameter. Front of shoulder is 2.220 inches, rear of shoulder is 2.150 inches, diameter at rear of shoulder is .454 inches. Shoulder angle looks to be 40 degrees.
My best guess is that this is 30-06 Ackley Improved that has been fireformed and neck resized. (It's about .15 inches longer to the shoulder than I have listed for AI by Nosler.) Any other guesses? Is there an extended Ackley or something?