Sorry, but the casing is close.8mm goes into a 30-06 with little or no effort, and was suspected of blowing up a number of low number Springfields.
8mm cases don't fit 30-06 chambers. Try it...and the bullet won't go into the position of the shoulder or neck of the cartridge. The bullet is way over the diameter of the 30 cal. Long and short of this is, try it. The 8mm cartridge stops about 1/4' short of going all the way in. No way it fits.
You sound like a troll baiting here.
If this was true, people here that are known and have displayed actual knowledge would have come forward to correct me.
You try it yourself. Don't look at a line drawing. This is how stories like this start, by people that have no actual hands on or knowledge spreading a story...
Regards, Jim
Well, FYI, I'm not a troll - but YOU have an attitude. An 8mm WILL chamber in my Eddystone M1917. I suspect that is due to "generous" wartime chambers, as none would chamber in my Remington M760 pump gun.
Some rounds will require a little bit of effort - some will not. Probably can write that off to variations in ammo lots. Perhaps you should read Hatcher's Notebook on blowups of low number Springfields before you proclaim your self as an expert.