Ha Ha ,LOL ! I knew you were gonna pull out the Federals. But your mistaken The 100gr barnes has 42 inches of drop, its your 90 gr. siera that has 34 inches of drop.
While the .243 in 85 gr federal siera has a velocity of 2180 at 500 yds with energy at 890which is about 100lbs less than your 100gr.barnes but 300lbs more than your 90gr. siera, and only drops 32 inches at 500 yds with a 200 yd zero.

Ha Ha ! LOL. man I love talking guns.
see I can shoot federals too. LOL.
Ps the .243 with the 85gr.siera has 18.8inches of wind drift at 500yds while the your 100 gr.barnes has 22in.

Do a search on .243 ammo and youll find 115 gr bullets for handloading
Dont know anything about ballstics but I hear guys getting some awsome numbers with hot loads.