Yes AA2015 is the worst fast powder I've used. Re7 is much better but to fast a burn for .243 don't use either!!! Over pressure happens fast. Unless you are loading light bullets like 60gr. and under. The .243 all the way up to .308 like medium burn powders. I have all the load books by all the makers and I have always used Sierras load data as my go-to book or as reference when using other bullet brands. Always use the bullet makers data FIRST! Then try other books data if you get poor results. Sometimes I have 3-4 books out at once then test test and test some more.
That powder IMR4350 works best with heavy bullets in the 105-107gr. range. But you don't have the twist for them and its not worth buying a fast twist barrel for 243 in this game. Trust me I did it and still have the barrel. Stick with the factory barrel then switch to either 260 rem or 7-08 when you need to. Stock up on the IMR4064 load up some test loads and have fun. Proper powder burn is more important to a bullets flight than most other factors.

Most of the slow burning powders work well in the 308 based cases. I have had good luck with 4831 in both my 243 and 260.

Ken, limited experience, but I shot a couple matches at one range with a 243. I used a slower load (around 2,750 fps) with 100 Sierra flat base hunting bullets, sorry I don't know the number. 38 and 39 grains of AA4350. I had pretty good success on rams, as I recall over 50% of what I hit fell. The head and high rear are generally effective. Good luck with it, it will be fun and good shooting.

The IMR 4350 load of 35.2 grains with the 100 grain bullet is a starting load in the Sierra manual.