Try the Sierra 85 BTHP with either IMR 4064, Varget, or IMR 4350. I've owned a bunch of 243's with conventional 9 to 10" twists and all of them shot this combo extremely well.It’s getting a little cool up here in Delaware. 70-80’s. I’ll be heading past you in a week and a half, on my way to Kerrville. I need to work on my tan.
Bedding will help your accuracy. So will free floating the barrel. Both are pretty easy to do.
I recently bought a nice old 243. I’ll be looking for loads too.
Another positive with this bullet, it can be used as a multipurpose bullet for varmints / predators and white tail deer.
PS: Thanks again for those 85's you gave me several years ago.