Mr Gilmore, who was 44, was shot in the neck while he was in his car in Carrickfergus on Monday afternoon.
He died in hospital on Tuesday.
George Gilmore was shot in a “ruthless attack in broad daylight” police said.
Brian Roy McLean, 35, of The Birches Carrick and 28-year-old Samuel David McMaw of Starbog Road, Kilwaughter appeared at Laganside Court on Saturday.
They were jointly charged with murdering Mr Gilmore on Monday, the attempted murders of two other people on the same day and possessing a firearm and ammunition with intent to endanger life.
In court, both the accused spoke only to confirm their names and that they understood the charge.
There was no application for bail and both were remanded in custody, to appear again by video-link next month.
As they were taken from the dock, supporters who had packed into the court leapt to their feet, clapping and cheering.