Jimm - I have a 243 AI in the works as well so keep me posted on your technique and any problems.
I did a search on fireforming on www.reloadbench.com
and found some usefull info there.
There has been several post on this site for the 280AI and a ton of info there as well. A search will get you headed in the right direction.
Another place I found was www.anglefire.com/nd/243ackleyimproved/
this has some other links that may help.
I can't wait to start loading for mine. I'll use my current load and work up from there.