razmuz,
There is a short article concerning the 4350's in the December 2002 issue of Handloader Magazine. This article indicates AAC-4350 then IMR-4350 then H-4350...Listed slowest to fastest. It would be worth looking at this short article.
Personally, AND I DON'T RECOMMEND THIS, I have used them interchangable in my 270's. I always started with the lightest charge listed for a particular bullet and went from there. Never had a problem. Maybe I was lucky!!! Actually I don't use it much anymore since I mostly use surplus powders now and avoid the high cost per pound of canister powder. Good-luck...BCB