L Sherm is correct. The reason i went to AI 40° cases years ago was not so much velocity increases ( which vary cartridge to cartridge), rather, it minimizes or stops case stretching. I haven't had to trim my AI cases in a long time.
When I built my 6.5-06AI many years ago I also had a .25-06. I wanted a 6.5-06, but the ammo being so similar in appearance to the .25-06, I opted for the AI version of the 6.5-06.