William Frame, 55, took the gun from a locked cupboard and discharged it through the open window and out into the garden.
Relatives - understood to include his wife and father-in-law - took refuge in the toilet and locked themselves in as Frame went on the rampage.
At Perth Sheriff Court, Frame - the founder of property company Braemore Estates - admitted conducting himself in a disorderly manner on June 16 last year.
Frame, from Gamefield, Ochtertyre, admitted shouting and swearing and threatening to kill himself at the family home near Crieff, Perthshire.
He admitted taking a shotgun from a locked cabinet and firing it through an open window into the garden, which caused fear and alarm to other people in the house. The charge states that they hid in a locked bathroom.
Sentencing on Frame was deferred for background reports until next month.
He had previously been banned, as a condition of bail, from contacting his wife and father-in-law after being charged with the offence.
As special conditions of bail, he was banned from approaching his wife Wendy Frame, or returning to Gamefield. He was also prohibited from visiting his father-in-law. The businessman has owned a series of property interests and has been involved as a company director with a number of businesses including Paparazzi Restaurants.