I don't think you are going to find anything to fill a 22-250 case, unless you dislike velocity, efficiency, and barrel life.
I have found 8208 xbr to be absolutely fantastic in the 22-250. Nothing else I have tried can touch it for velocity and accuracy. It is also very temp stable and cheaper than most anything else. I think I got my last two pounds for $25 each.
I always like to run mildly compressed loads as well, but can't in the 22-250. And hey less powder is cheaper.
What was your load when you started to see flattened primers? What was your velocity? and did you see any other pressure signs?
**Edit** - sorry, I missed the AI part.