We've been loading Speer GS 100 grainers for my Daughter's Savage .243 for 10 years with good(but not great) accuracy. I was willing to give up one hole groups for the performance advantage of the GS. Last year I loaded some Nosler solid base 100 gr but didn't see much diff in accuracy. Her Savage is just a 1"-1.5" shooter with 100 grainers regardless of load or brand.
Other Savage 243's I have are pretty good using 90-95 grain Nosler BT but I haven't shot them much with anything else. I tend to find one "good enough" load and stick with it.