Putin travelled to India with Russia's defence and foreign ministers in a visit that saw the two countries reinforce their ties with a military and technical cooperation pact until 2031 and a pledge to boost annual trade to $30 billion by 2025.
The Russian president is visiting India amid increasingly strained relations between Russia and the United States, also a key Indian ally, which has expressed reservations about the growing military cooperation between Moscow and New Delhi.
A joint statement published after the talks said Russia and India had "reiterated their intention to strengthen defence cooperation, including in the joint development of production of military equipment."
In addition to the deal for India to produce AK-203 assault rifles, Russia said it was interested in continuing to provide S-400 air defence missile systems.
India's Foreign Secretary Harsh Vardhan Shringla said the two countries had signed 28 investment pacts, including deals on steel, shipbuilding, coal and energy. He added that a 2018 contract for the S-400 missile systems was currently being implemented.
"Supplies have begun this month, and will continue to happen," he said, referring to the S-400.
The deal with Moscow puts India at risk of sanctions from the United States under a 2017 US law aimed at deterring countries from buying Russian military hardware.
Russian oil company Rosneft said it signed a contract with Indian Oil to supply up to 2 million tonnes of oil to India by the end of 2022.
The countries also signed a memorandum of understanding for Russia to send an uninterrupted supply of coal to India to support its steel production, among other deals.
Putin and Modi also discussed the situation in Afghanistan, voicing their commitment to ensure that the country will never become a safe haven for international terrorism.