The army also intends to mount the expected 90-pound HMG on light-strike vehicles and infantry fighting vehicles.
Ammunition for the .50-caliber HMG is to include firebombs, armor-piercing high explosives and armor-piercing discarding sabot, a Defense Department request for information said.
Rate of fire will be at least 450 rounds per minute and it will have sighting systems including optical magnification, open-sight and thermal imaging.
Additional specifications include a fire-control system to be operated manually and electrically. A spare barrel is to be available that can be changed quickly while in the field and in adverse conditions.
The weapon will have a blast suppressor to reduce blast effects. Smoke generated during firing should not hinder the operator's view.
"The weapon should be easy to carry by a three-man crew in dismantled condition and be assembled with ease while being used in a ground role," a report by the Press Trust of Indian said.
The weapons should withstand operational conditions in high-altitude areas, jungles and deserts.
The specifications are almost identical to the Browning M2HB HMG already in service with the Indian army, according to the defense news Web site livefist.com, run by television and newspaper defense correspondent Shiv Aroor.
The other 12.7mm vehicle-mounted HMG with the army is the automatic only Russian NSV.
Defense Web sites describe the NSV as a gas-operated and air-cooled, belt-fed weapon that fires from an open bolt. The gas system consists of a gas chamber below the barrel, with a gas regulator and a long-stroke gas piston attached to the bolt carrier. The gun body weighs around 55 pounds and 90 pounds on a tripod with 50 rounds of ammunition.
RFIs for the new HMG have been sent to agencies including Rosoboronexport for their Degtyarev Kord 12.7mm, Aroor noted.
The Kord entered service in Russia in 1998, replacing the older NSV and appears similar to it. But the internal mechanism has changed from a horizontally pivoting breech block to a rotating bolt design. The gas system has been changed and the muzzle-baffle redesigned. These changes reduce recoil compared with the NSV, allowing greater accuracy during sustained fire.
An RFI has also gone to General Dynamics for the still under development M806 and also their Browning M2E50, a variant of the M2.
Thearmy's HMG RFI comes after the Indian army notified the market at the start of the year that it is on a hunt for a substantial number of firearms that shoot around corners.
The weapons, often called cornershot guns, must also have an accuracy to "engage targets effectively" of just over 200 yards and be capable of day-night vision for use with the army's counter-terrorist operations.
The move has come about because of the Nov. 26, 2008, terror attacks on hotels, train stations and other buildings in central Mumbai, killing 173 people. During the so-called 26/11 attack, the military was involved in a lot of room-to-room fighting in the large Oberoi Hotel, according to a report in the Times of India newspaper.
The weapons are essentially an adaptor for pistols and rifles that is hinged in the center. It can be bent up to 60 degrees, allowing the shooter to see a direct line of fire around a corner, thanks to a small side-mounted video camera. The shooter has no need to show himself to the enemy.