I'm not familiar with the AI Whelan, but was quite surprised to read your claims covering all Ackley Improved cartridges. Ackley himself regarded some, maybe even many of his improved versions as experiments that proved to provide little to no value.
At the same time there are several that were regarded by him as being worthwhile. I have several I do feel have been worthwhile chambers. Examples - 2 I feel are significant improvements are the 250-3000 AI and 257 Roberts AI. At the same time, I have a 30.06 AI that probably could be considered an insignificant improvement.
Could you expand any on the facts you refer to? I would be interested in reading them. I'll promise you I'm not interested in getting into an internight fight, and will disappear into the woodwork before letting the thread go downhill, but would like to see your basis.
The .250-3000 and the 257 Roberts AI are the most often stated examples of improvement.....I should add to this the 7MM Mauser.....as all of these when chambered in their original configuration in a modern bolt action rifle and fired at the pressures of modern cartridges show excellent performance differences.....the addition of AI dimensions after this do very little for them.....I actually had a guy tell me he was getting what amounted to be velocities in excess of .257 Weatherby velocities from his .257 Roberts AI.
One can (if he has the equipment to gauge the pressure accurately...and the usual reloading indicators don't do this for you) actually shoot to about 70,000 PSI with little to no serious pressure indicators. Unfortunately the shooter don't know this because he hasn't the equipment.
It's a commonly believed rule of thumb that for every increase of case volume of X %, that 1/4th of that is realized in velocity increase.....and this rule of thum has been born out many times...Example:...if one can blow out the case to increase it's inside volume 10% then he should realize 2 1/2 % increase in pressures.....any additional increase in pressures is due to actually firing the case above the saami pressures of factory loaded ammo.
Or in other words almost all the gains one gets from the AI cartridges could have been realized with the parent cartridge if loaded to the same pressures one loads his AI cartridge.
A cartridge with 10% increase of capacity if originally shooting 3,000'/sec will be expected to now shoot 3,075"/sec and very few can actually be increased 10% in volume. Among those that can are the .300 and .375 H&H and if one looks to the gains of the .300 and .375 Weatherby he sees that loaded to the same pressures as the .300 H&H there's actually very little gain.
When it comes to the fine old cartridges such as the .257 Roberts one needs to find loading data for it that makes it shine as it should.....but make no mistake about it in no way is it ever going to be a .25-06. It's a fine cartridge as is and the AI version actually don't gain 100'/sec in reality.
Probably no other group of cartridges have had so much money wasted on them as the Ackjley cartridges.....if it improves confidence then so be it....but to say that it actually makes a (noticible) difference is just not correct at all.