Here are my one rifle lists.
Texas: Kimber Montana in .223 shooting 64-grain Nosler BSBs
US: either custom FN .270 in Bansner stock or Remington 700 KS .280 either shooting 150 Partitions.
World: Kimber Talkeetna .375 shooting 270 TSXs
No Irons needed that's what extra scopes are for.