This is far from being a stupid question. If you don't reload, you choices for varmint ammo for the .243 Winchester are fairly limited. Many suppliers are out of stock on many varmint loads for the .243 Win. Check Midway, Cabelas, etc. to see what is in stock.
If I were hand-loading, I would consider the 75 or 85 grain Hornady V-Max. Lapua, Sierra, and few other premium bullets are also available.