Loaded For Bear Meaning

(idiomatic) Mentally prepared for a daunting situation or confrontation.

Example: 1955, Edward Latimer Beach, Run Silent, Run Deep, ch. 6:
  "The whole Jap Navy," said Captain Sams, waving at a map of Japan on the wall behind him, "has been steaming across the Pacific loaded for bear."
1917, Lucy Maud Montgomery, Anne's House of Dreams, ch. 35:
  Every Elliott and Crawford and MacAllister is on the warpath, loaded for bear.