Rita King, 81, was killed at De La Mer House in Walton-on-the-Naze in Essex on Monday.
Her husband, Ronald King, of Cedar Close in the town, is charged with murder. He appeared at Chelmsford Crown Court via video link from HMP Chelmsford.
A plea hearing was set for 3 March and a trial provisionally set for 4 July.
Mr King was asked if he could hear the court proceedings, to which he replied to the court clerk "yes, dear".
His barrister said he would not be making a bail application.
Mrs King was understood to be suffering from dementia. A post-mortem examination found the provisional cause of her death was a gunshot wound to the head.
Essex Police said the bullet came from what was believed to be a 1934 Enfield revolver, which was found at the scene.
An 86-year-old man could stand trial next year for the murder of his wife, who was shot dead in a care home.