After reading a bunch of internet hoopla, I was not a huge believer in the .30-06 AI...Until I built one. I already had 2 Ackleys at the time, so I was already aware of all the benefits of the Ackley case design, and the 40º shoulder and the low wall taper. So if I built an '06, it would definitely be an AI version over the regular Springfield version, just for the case benefits, if nothing else. I was getting components together to build my .280 AI, and then a buddy of mine told me had gotten a new factory Remington take-off 26" heavy .308 Win barrel and wasn't going to use it because it was a 1:12 twist, and he only wanted what he paid for it ($50). So, my .280 AI got put on hold, and I decided to build a .30-06 AI instead, since all the parts were there.
I was never a fan of the .30-06. My uncle has used one my entire life, along with most of the hunters I know, and so have probably 50% of the hunters in Alabama. You go to just about any hunting camp and I bet at least 1/2 of them are using a .30-06, and 1/4 of the rest are shooting a .270, and the rest a mixture of magnum and other random cartridges.
So anyway, my smith told me that since I was already aware of the gains of AI'ing a cartridge, since he had already built me a .25-06 AI and a .300 Ackley, that I would notice only a small velocity increase in my .30-06 AI... So, I still went ahead with it. And after forming cases, and doing some load workup, this thing is WELL over standard .30-06 velocities. Granted, I'm pushing them to the ragged edge of sanity, but I am not seeing any excess pressure signs other than slightly flattened primers. And my cases still look good after several firings. I have noticed that the Ackley Improved cases seem to handle pressure better. But when you do find the max pressure, you're on a razor's edge between being fine, and over pressure. The signs don't seem to appear like they do in normal case designs, where you can see gradual pressure signs. The Ackleys you go 1/2-grain too hot, and you're blowing primers.
So, that being said, just be careful, but if you do your due-diligence, and slowly work up in .1 or .2 increments (which is a good idea when dealing with ANY wildcat cartridge that does not have any published load data with modern powders and bullets), you can get some great velocities at non-excess pressure levels with slow burning powder and 185's in the .30-06 AI.
