The victim, identified as Shahrukh, was rushed to a hospital but succumbed to his injuries on the way, SP (Rural) Pankaj Pandey said.
Shahrukh ran his shop in Dhakar village under the Khurja Police Station in the district. One Saleem, 25, of the same village visited the shop with two other persons and asked to serve him first, the police officer said.
On refusal by the barber to oblige him, Saleem shot him with a country-made pistol, seriously injuring him. He later succumbed to injuries while being rushed to Government Hospital at Khurja, he added.
Two of the accomplices of Salim have been arrested while Salim is absconding, Pandey said.