Joel and Rich: Thanks much for the info. I have fired normal 25-06 loads through my AI, but they do not group well until the case is properly formed. You can get an idea of which load will work best, but you need the case formed before you know how good your results will be. I started out using Winchester brass for the AI (don't ask me why, lol), but never got even one good case. Even if I annealed the case prior to forming, they all split in four places right on the shoulder regardless of the load. I checked with my local gunsmith and he told me to go to any other brass other than Winchester. I tried Remington and had no problems. I have since switched to either Nosler or Lapua brass for everything. I will concede that the Lapua brass is better, but I still prefer the Nosler.
Rich: the method you describe for the .30 Gibbs is exactly what I do; neck them up to .338, then run them through the Gibbs full length sizer to create the false shoulder for them to headspace on. I tried just using a Gibbs neck sizer, but for some strange reason, they will not chamber. I have compared the two cases by measurement and by comparing them side by side under a microscope and I can find no difference, so that is a mystery. I anneal all the cases before I start, and I have never split a case. I appreciate your info on the pistol powder process. I will load a few of those and see what I get. Despite its kind of goofy look, I really like the .30 Gibbs. The rifle I used is a Remington titanium that I bought on an impulse. I got it the first year they produced them and mine has a serial number in the 60's. So the first thing I did was screw it up and cut off at least half the value. I wish I could leave stuff alone. It shoots very well considering it has a barrel the size of a fat ball point pen, and, in fact, I was using it when I made the longest shot of my life...837 yards. The bullet went right through the middle of the deer's heart, and no one was more astounded than me. I could never repeat that with any of my long range rifles, and most likely would not try anyway.
Why would using 270 brass make a better case when it initially has to expand so much more than 30-06 brass, plus, despite popular belief, the 270 is not a necked down 30-06?
I will check out the 30 Sherman. I have five or six 30-06's I could play around with.
Thanks for the info on the Gibbs, but I still need a powder charge for the AI if you have it handy. Denny