Re: Need advice to pick a .243 bullet.
IMO i would go with a 90 gr. Nosler Accubond, extremely accurate out of all 4 of the 243 win.'s I own, or the 85 grain Hornady Interbond, also bery accurate. these bullets both offer rapid but controlled expansion to get the job done on whitetails out to 400+ yds as well as expand fast enough to produce ethical kills on varmints.
My dad has used the Sierra 100 gr. SBT gamkings since he was 12 and has had success with accuracy, under 1" groups at 100yds, and killing everything from large whitetails to groundhogs out to 400yds without issues.