"but they dont 100gr ballistic tips for a .243 that i can find".

But they do make 95gr Btips for the 243/6mm. Have seen what they do from a M7006mm Rem. Should work fine in your 243, if it will shoot them accurately.

If you don't reload, Winchester offers them in the Supreme Ballistic Silvertip line and Federal offers them intheir Premium line. Hornady ammoalso has the 95gr SST available, at a bit less money than the WW and Fed. loads.