The Indian Army like many of its purchases has had major goofups
with its small arms procurement while the police forces were much better.
Small arms are the basis for any defence force , it perhaps has more impact on
a conflict than even nuclear submarines and aircraft carriers. Providing the
right small arms for our troops can save a lot of lives, boost morale and
lethality.
The recent flip flops on the calibre is worth noting and it
is extremely critical to understand existing shortfalls and weed out the
misconceptions. The Indian Army has decided to go for the 7.62x51mm calibre for
its new assault rifles to replace the INSAS. This comes after failing to find a
suitable Multi Calibre Rifle capable of firing both the 5.56x45mm(for
conventional conflicts) and the 7.62x39mm(for counter insurgency) ammunition
with interchangeable barrel, buffer and magazine. This rifle would come in
conversion kits with additional tools to change calibres in the field or at the
armoury. The trials not seem to have gone well, there may have been problems
with the reliability of such a complex design or too many design compromises
for multicalibre capability or may be it was just cheaper and risk free to induct a common calibre
which can be used in both counter insurgency and conventional warfare. The
return of the 7.62x51 has a good range and good lethality but the platform
tends to be heavier, more expensive and uncontrollable in full or even in
bursts which can be an impediment in close combat in built up and jungle areas.
The army may be thinking about employing 5.56mm carbines at such short range
engagements and they have their place but they are what they are ,carbines which are
less flexible than full length rifles even in close combat.
Desert Tech MDR . Source - Canadiangunnuts
The 5.56x45mm calibre - Misconceptions with the ARDE and the
Indian Army:
The common misconception with the Armaments Research
Development Establishment(ARDE) and the Indian Army is that the 5.56x45mm round
was designed to incapacitate or injure the enemy rather than killing him, thus
a myth started to spring up justifying that in conventional conflict injuring
enemy soldiers used up more resources of the adversary than killing the
soldiers. The ARDE and the Army are right to extent ,the round designed and
used by them through the INSAS rifle can only injure the enemy and not kill
him, even at close ranges. Lets look at why the round was created.
The evolution of the 5.56x45mm ammunition and the AR-15:
The 5.56x45mm became implemented as a military round in
the AR-15 designed by the legendary Eugene. The idea behind it lied in the
science of "wound ballistics" which indicated in tests that if a
smaller lighter bullet is fired at high velocities it tumbles violently upon
entering a different medium(Eg . Flesh/ballistic gel) thus breaking up easily
and creating a large cavity. The critical aspects which dictated the size of
the cavity were the velocity of the bullet
1.Velocity of the bullet at the target end had to be
greater than a threshold which is about 720-750m/s. A standard M-16 can keep a
bullet over that threshold for 200m.
2.The stability of the bullet, higher the stability
lesser was the tendency to tumble.
3.The integrity of the bullet itself. Higher the
integrity lesser the tendency to breakup.
4.Length of travel in the medium. An entry through the
stomach had a higher chance of tumbling than an entry through the limbs.
5.The yaw characteristics of the bullet. A bullet with some yaw would tumble more upon entering flesh.
The wound channel created upon tumbling and fragmentation of the 5.56mm round. Source - http://www.discussionist.com
Fragmentation at different velocities .Source - http://www.ciar.org
The high velocity Russian 5.45mm round creating a cavity immediately after entry. The steel core 7.62x39mm fragmenting later than the lead core 7.62x39mm. Source - Wiki
Stoner was aware of this and started to design a rifle
the AR-15 which could be lethal under 300yards(275m ), he had also earlier
developed the AR-10 which was a 7.62x51mm rifle and would be his primary
offering to the US Army. The US special operations forces were quick to recognise
it, adopt it for operating in the jungles of Vietnam and with immense success.
The balance of the weapon,lightness, the rate of fire,flatter trajectory, accuracy and the
lethality of the round at close ranges were very handy. The 5.45x39mm ammunition ,a similar round used by the soviets in the Afghanistan had a reputation of being known as the poison round for its nasty wound inflicting ability.
The weapon was later recommended for large scale adoption
by the US Army, the Army Material Command which was averse to an outsiders design
replacing its own M-14 stepped in to make certain "improvements" to
an already proven, good design which resulted in the M-16. They changed the propellant
powder in the ammunition from the stick powder based IMR used by Stoner to a
ball powder(from their traditional supplier) , this made the rifle dirtier in
operation, distorted the harmony of the operating cycle thus making the rifle
unreliable. In low temperatures ,they found that the accuracy of the wasnt good
thus increased the twist from 1:20 to 1:12 to stabilise the bullet and make it
more accurate but it also meant that the tumbling tendency will decrease. With
later variants such as the A2 and A4 there was a demand for higher range(500m)
and the ability to defeat body armour at long ranges, thus a heavier denser
bullet was introduced with a steel penetrator (SS109/M855)and to stabilise the
heavier bullet the rifling twist was increased to 1:9. The M-4 with shorter
barrel of 14.5 inches as compared to the 20 inches of the original coupled with
the higher power M855A1 "green" cartridge worsened the already bad
problems.
The rise of the "incapacitating round" myth:
With the above mentioned developments the M-16 in combat
could not replicate the same kind of wounding characteristics on the adversary
as it initially demonstrated. The ammunition upon entry created a smaller
channel due to the reduced tumbling and breakage which meant that the adversary
would continue to be conscious and thus capable of returning fire even after
being hit. The results were even worse if the bullet hit the limbs, so soldiers
had to aim and hit the torso for any meaningful damage.
With rising dissatisfaction of the troops with the
lethality of their individual weapons the higher ups had to justify their
adoption and usage of the 5.56mm round, so they came up with the explanation
that the round was intended to incapacitate the enemy by injuring him and not
kill him thereby using up extra resources of the enemy. Seemingly everyone
bought it, unfortunately so did the Indian Army and the DRDO. It is not very
clear if they had conducted any preliminary studies and carried out tests with
existing weapons before going about designing and adopting our own weapon based
on the 5.56mm round.
The INSAS rifle:
The INSAS rifle which had a lot of problems after its introduction went through a painful
and long refining process with its 1B1 variant being somewhat reliable and has
eliminated some of the earlier problems. Despite doing all that it still
remains long,heavy, cumbersome then similar designs like the FN FNC,Polish
Beryl, Romanian . Scientists at ARDE had used some modern materials like
polymers for the foregrip, magazines, stock and yet couldnt bring the weight
under similar weapons of the same class which use traditional wood furniture
like the AKM,VZ-58. The additional complexity of the 3 round burst mechanism is
also behind some of the reliability problems.
It had a limited magazine capacity of 22 rounds but
usually held less than that to prevent
spring wear and the feed problems that come out of it. This means it has to be
reloaded more frequently in a firefight.
As far as the ammunition goes, the bullet(Steel insert
Ball) weight of the INSAS is 4.16gm and NATO equivalents is around 3.5gm.This means that a heavier bullet
needs a higher twist rate 1 in 200mm ,in US terms close to 1:7.8 which is
higher than even the latest M-16s of 1:9 . The muzzle velocity such a bullet in
the INSAS is 900m/s which is 60m/s lower than the M-16. In short the INSAS
adopts the same lethality problems from the M-16A2 but also made it worse. The
INSAS may be accurate to a good range but compromises on its lethality at
ranges even below 300m within which most of the engagements take place.
INSAS 1B1. Source - Wiki
Operational Lessons and their impact on small arms
adoption and deployment:
Combat in different terrains like deserts, jungles,
mountains ,low temperatures has shown that there is no one size fits all calibre.
In the jungles where engagement ranges are short the
5.56mm would be a good choice for the rifleman backed up with 7.62 marksman and
light machine guns to penetrate the foliage at longer ranges.
In mountains a good amount of engagements are still going
to be under 300m but targets many times were identified at longer ranges .Engaging
such targets by maneuvering close to the target to engage them increased the
risk of an ambush, so such targets were engaged with long range snipers
,machine guns ,mortars or even artillery. So dismounted troops primary weapon
of choice to engage longer range targets was the barret m82 as it puts the
friendly troops out of enemy engagement range, followed by maneuvering and
engaging with 7.62mm machine guns and
Designated Marksmans Rifle.
The L-129 Designated Marksman Rifle. Source - firearmblog
In plains or in deserts engagement ranges beyond 500m are
low and significant under 300m.Thus similar to the mountainous range it would
need 7.62 DMRs, LMGs and 0.50cal snipers.
Possible options for the INSAS family replacement:
1. A 5.56x45mm rifle optimised to be lethal at ranges
upto 200m(a good hit can drop the enemy dead) and meaningfully effective upto
300m(a good hit can totally incapacitate or make enemy unconscious ).Such
rifles are rare on the market but can be made easily by existing manufacturers.
2. A Designate Marksman Rifle(DMR) preferably a bullpup
design which can enable its use in close quarters too. An accuratised version
of the FAL can be done on existing stocks can be done similar to the M14EBR
with a better buffer, floating barrel, long range scopes, foregrips, bipods,
foldable/collapsible stocks. There is the bullpup variant of the M14 which has
been used by special forces in combat. There are other bullpups coming up like
the Desert Tech MDR.
The SRSS Bulldog 7.62X51mm bullpup DMR in Afghanistan. Source : defensereview
3.A sub compact weapon with a very short barrel for use in room clearing, in vehicles, special ops, Personal Defence Weapon(PDW). It would be lethal upto 100m and meaningfully effective upto 200m.
A quick propellant burnout so as to reduce flash, sound
and recoil in a short barrel. Subsonic ammunition can be usefull in special ops
as they are more silent when used with a suppressor and make the gun less dirty.
The 300Blackout is avery good candidate as it offers good energy from a short
barrel and comes in subsonic types too, it is being adopted by the US special
forces.
4.A 7.62x51mm Light Machine Gun with a backpack
ammunition feed system to minimise ammo change time and to enable longer continuous
fire time while walking. The Negev NG7 comes with such an option.
Negev NG7 beltfed LMG chambered 7.62x51mm. Source - defensereview
Concept rifle for INSAS rifle replacement:
The idea behind the INSAS was to have a cheap, reliable,
controllable rifle provided to out armed forces. After the IPKF experience it
was found that the lower 7.62x51mm ammunition carried poor controllability in
the heat of battle was to be corrected. Whether it corrected them or not the
INSAS created other problems some of them were not the sole fault of the DRDO
but also the armies maintenance practices(rectified now) and the OFBs poor
quality control(one can only wish if this can ever be rectified).
The similar requirement will be carried on for the new
design.
The General design:
It would be a
design which bridges the assault rifle and a section LMG like the H&K M27
IAR being able to bring accurate suppressive fire on the adversary. It would
have an open bolt and closed bolt operating mode, the closed bolt mode will be
used in the semi auto mode(if possible both modes can be linked to a single
ambidextrous switch) and the open bolt will be used with the automatic mode to
reduce the risk of cookoffs . It will employ a recoil mitigating mechanism like
the "soft recoil" mechanism developed by James L Sullivan for the
Ultimax LMG .The receiver would be made of stamped sheet metal steel to keep
the cost down and for ease of manufacture. It would have ambidextrous and
ergonomic bolt release, charging handle and magazine release switches.
The LWRC Infantry Automatic Rifle with open bolt and closed bolt modes for semi auto and full auto respectively
The Soft recoil mechanism:
It is a mechanism where the recoiling force of the
recoiling mass ie the bolt or the bolt+piston(in case of long stroke piston)
,is transferred to the buffer over a stretched period of time rather than in a
short intense blow by using a set of springs.
Recoiling mass = m, acceleration of recoiling mass due to
recoil= a
Recoil force= F=mXa ==m X dv/dt
where dv- change in the velocity of recoiling mass , dt -
time taken for the change in velocity.
Thus by increasing dt the force imparted is reduced and
not only that , the force impulse is also reduced by having a constant force
which means the shooter will find it easier to keep the sight on the target.
Ultimax soft recoil LMG demonstrates very high controllability at full auto
Barrel:
The rifle would have a tooless quick removal barrel with
the barrel removed with a barrel release catch like the MG-10 concept rifle.
The barrel replacements should be precise and not affect the accuracy of the
weapon. Quick barrel change may be used to switch between rifle n carbine
lengths or to continuously laying suppressive fire without overheating the
barrel as used in the Ultimax. This would enable the use of lighter, cheaper
barrels . It would have barrels of 2 variable lengths.
1. 20 Inch barrel for the rifle(with 1:20 twist)
2. 16.5 Inch barrel for the carbine
Barrels will be cold hammer forged steel barrels with
chromium lining to extend life.
The armwest MG-10 with quick barrel change.
Gas Block:
The rifle will operate on the short/long stroke gas
piston mechanism. The block will be easy to remove and clean. It has two gas
settings for the two barrel lengths.
Stock:
It will be a folding and collapsible stock like the one
used in the like the one used in the FN SCAR.
Magazine:
To reduce the frequency of magazine change due to the
higher use of auto fire a 60 round and 100 round magazine will be used without
lubrication, the sure fire 60 round and 100 round magazines are an example. Drum
magazines like the C Mag can also be used. The ususal 30 round magazines can
also be used.
Sights:
The top mounted picattiny rails can accommodate red dot ,holographic,
image intensification mounted on theMIL-STD-1913 picatinny rail on top of the receiver along with a built in iron sight.
Picatinny rail mounted ACOG sight on a M27 IAR. Source - smallarmsdefensejournal
No comments:
Post a Comment