India's new Modern Submachine Carbine (MSMC) and 5.56x30mm Ammunition

Steve Johnson
by Steve Johnson

During the past few years India’s Armaments Research and Development Establishment (ARDE) have been developing an interesting Personal Defense Weapon (PDW) called the Modern Submachine Carbine (MSMC).

Modern Submachine Carbine

The firearm chambers a round developed in India called the 5.56x30mm. This round is sometimes referred to as the “5.56x30mm INSAS” after the first gun to chambered the round, the INSAS Carbine.

5.56x30mm MARS

Those of you who follow the industry closely may recall that Colt developed a round named the 5.56x30mm MARS during the 90’s as part of their now defunct Mini Assault Rifle project. I imagine the INSAS cartridge is very similar. The Colt patent describes the MARS cartridge:

The MARS cartridge is designed as part of the weapon system and exploits the high energy densities of modern ball powders. It for the first time uses magnum pistol type powders burned at rifle pressures to achieve high rifle velocities in a short rifle barrel. It uses a fast ball powder to achieve 2600 ft/sec with a 55 gr full metal jacket projectile in only an 11 inch barrel.

The MARS cartridge/rifle was able to achieve similar ballistics as a ultra-short barreled 5.56x45mm NATO rifle (I use the term rifle loosely, sub-carbine is more correct), but with less muzzle flash, noise and weight. The Indians went with the 5.56x30mm over the 5.56x45mm for these exact same reasons as Colt.

Out of a 11″ barrel, the MARS Rifle was able to push a 55 grain bullet at 2600 fps, generating 825 ft/lbs of muzzle energy. For comparison, according to Wikipedia, the original Colt Commando (11″ barreled sub-carbine) could push a bullet (presumably a 55 grain M193 Ball) at 2750 fps.

Colt M4 Commando (current model)

While the 5.56x30mm has advantages over a pistol cartridge such as the 9mm NATO, to wit, less weight and kevlar vest penetration, it has in my opinion one fatal flaw. 5.56mm bullets were never designed to operate at such low velocities. While 2650 fp/s may seem fast, that is at the muzzle, not 200 meters downrange where the target is situated.

A graph I generated. Numbers are estimates for illustration only.

Col. Martin L. Fackler, MD famously did a study which determined that a 5.56mm bullet (M193 and M855) would fragment only slightly ,or not at all, when hitting flesh below the speed of 2500 fps. Low fragmentation results in a .22″ sized hole in the target – less damaging that a .38″ (9mm) or .45″ hole.

Col. Martin L. Fackler, MD results

It will be interesting to see how this new sub-carbine and perform in real life, and what official nickname the cartridge is given. I think 5.56mm India or 5.56mm Short should are much better named than 5.56x30mm INSAS.

Hat Tip: 8-AK Defense News and Ammoland

Tag: 5.56×30

Steve Johnson
Steve Johnson

I founded TFB in 2007 and over 10 years worked tirelessly, with the help of my team, to build it up into the largest gun blog online. I retired as Editor in Chief in 2017. During my decade at TFB I was fortunate to work with the most amazing talented writers and genuinely good people!

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3 of 18 comments
  • Jason B. Jason B. on Nov 13, 2010

    Why does everyone try to either replace one thing at a time or kill 2 birds with one stone. I say dump the whole system! Get rid of 9mm 5.56x45 and 7.62x51
    Replace all three with two rounds. One a PDW/pistol/sub carbine round two a dedicated rifle round that spits the difference between the 7.62 and 5.56 both in energy (1800-2000ftlbs) and diameter (6.5mm)

    i had a concept for a telescoped 77grain 5.56/5.7x38mm PDW round that would have the same base dimensions of a 9mm(for ease of transition). the bullet would be made primarily of two materials aluminum in front + lead in the rear (making it likely to yaw) with a thin copper jacket(to insure frag even at slower velocities) and a titanium tip to help penetrate body armor.
    the projectile would be a double ogive (double pointed) the rear facing lead side looking much like .22lr hollow point pointing backward(a lot like a boattail but longer) and the front being much pointier like a 5.45.

    the round would be optimized for a 16in barrel 2500fps and 1068ftlbs(assuming the right powder is used). Out of a 8 inch barrel I calculate a muzzle velocity/energy around 2095fps/750ftlb

    external ballistics are tough to predict because of the round’s COG (causing it to be slightly less stable) however it is easily overcome by the round’s shape and sectional density (giving it a high BC around .4+) at 400yards the round would actually have more energy than a 5.56NATO when both are fired from a 16 inch barrel. At 600 yards it officially goes subsonic and turns toward it’s base(and becomes a Hollow point)

    i predict the terminal effects would essentially be the equivalent of a 31grain 5.7 and 45grain .22mag hitting roughly the same spot at the exact same time.(fragmenting into two main pieces and causing two wound cavities that in places open up into one large one.

    • Rob Rob on Oct 15, 2012

      @Jason B. This is absolutely absurd. You're joking about all of the above, right?

  • Pepe romo Pepe romo on May 30, 2013

    They should call it the Akuzi.