Children were playing cricket at Bheti village in the district on Thursday when the ball hit Ramlal and Bijendra Kandari who were sitting nearby.
When Mahesh (12) went near them to pick up the ball, Ramlal fired at him with Kandari's country-made pistol, Ghansali police station in-charge Pradeep Singh Rawat said.
Villagers rushed the boy to a nearby community health centre from where he was referred to AIIMS, Rishikesh. He sustained a gunshot injury under his right eye.
Both Ramlal and Kandari were said to be drunk when the incident took place, Rawat said, adding that the duo have been arrested. The pistol used in the crime has also been seized, the policeman added.