With AI cartridges, same stuff usually comes up.
I wonder what speed you could work up to in the standard 223 using the same criteria for safe and same barrels. It is nice that there isn't published data for the 223AI so you can pretend your pressures are whatever you want.
Don't get me wrong, bang per the grain of powder and everlasting cases the 223AI is a gem. But compare the capacity of the 223 to the AI version and there isn't that much of a difference and there is no case shape magic that turns it into a 22-250.
I've run 75's in my 25-284 to almost 4000 fps with no pressure signs or benefit of AIing but knowing what a 25 06 runs pressure wise to get 3700 I have no allusions as the the pressures not being way up there. Got a 223AI as well.
OK......
My standard .223's, 14" twist......one is a rechambered (very minimal chamber, 0 freebore) Rem. 700 sporter barrel, 20" long....the load it always shoots is VV133/40VMax at 3895. Another is a 26" Shilen, most accurate loads are AA2015/50gr bullet at 3630.....a 40BT with 1gr. more powder = 4010.IMI brass. These are the most accurate loads.....NO signs of overpressure even in over 100 degree weather.
The .223AI's....all are 14" twist, minimal chamber, .250"nk, 0 freebore. The good one is a 25" Schneider barrel.....most accurate loads...... AA2015/50gr bullet = 3825.....AA2015/40BT = 4200. NO signs of overpressure. Other lesser quality barrels (2) chambered by the same person with the same reamer are 150fps slower with the same 40gr load.
Brass is IMI exclusively, primers Rem 7-1/2BR, bullets have thin film of Lee Lube and are seated .005"-.010" off lands. Some people just don't seem to get it.....there's no attempt to push velocity, loads are chosen because they're most accurate and velocity is whatever it is. And again, these loads show NO signs of overpressure, primer pockets stay nice and tight. All of them have been used for years and in some very hot weather.
The .284 case is pretty much an "improved" case as is, the 06 is a very old design. They're very different.