The accused were identified as Ram Babu (39) and Prem Pal Singh (51), both residents of Aligarh district of Uttar Pradesh, police said.
The two were arrested by the Special Cell of the Delhi Police on June 27 and 20 factory-made sophisticated pistols were seized from their possession, they said.
"A secret information was received that two persons will come at bus stand in Salimgarh bypass area for delivery of illegal firearms on June 27. The accused were arrested from there," said a senior police official.
He said the accused told the police that they paid Rs 10,000 for each pistol and sold them for Rs 15,000 each.