M230LF Alternative for .50cal & 40mm AGL??

ATK 30mm M230LF ChainGun

An Alternative for Weapon Systems

to Replace

.50cal and 40mm AGL?

The story of the M230 30mm autocannon begins with Hughes Helicopter in early 1970's thru the effort to develop AH-64 Apache Helicopter. 

M230 ChainGun is now part of ATK's ChainGun family.

AH-64 Apache M230 30mm ChainGun

M230 forms an integral part of the Apache helicopter with its 1200 round magazine. It enables he Apache crew to engage fortifications, light armor and personnel in the open.

M230 30mm ChainGun

Ammunition

M230 fires 30x113mm ammunition. The ammunition was first developed for British ADEN and French DEFA 550 revolver cannons in 1950s. These guns were developed for aircraft usage.

30x113 Ammunition

One common mistake about M230 gun and its ammunition is to think that it is better than the 25mm (25x137mm) and/or equal to the larger 30mm-30x173mm that is fired from Mk44/MK30 cannons.

In fact, 30x113mm ammunition can be best described as 'Light 30'. The following image shows the size comparison of 30x113mm and its big brother 30x173mm rounds.

You can see from the above image that, 30x173mm round fired from Mk44 cannon has a lot bigger punch than the M230's 30x113mm.

Three types of ammunition were developed for M230. These are:

• M788 TP Target Practice
• M789 HEDP High Explosive Dual Purpose
• M799 HEI High Explosive Incendiary

Lethality

For AH-64 and MH-60L Direct Action Penetrator helicopters, the preferred and widely used combat round is M789 HEDP. Some of its characteristics:

• Weight: 350grams
• Muzzle velocity: 805 m/s
• Anti-personel effect: 4m lethality radius
• Penetration: 25mm thick RHA Rolled Homogenous Armor at 50degree obliquity at a range of 500m

As comparison for lethality, 25mm APFSDS round that can be fired from a M242 Bushmaster cannon penetrates around 45mm RHA at 500m range.

The penetration for 30x173mm APFSDS round that is fired from Mk44 can easily penetrate about 55mm RHA at the same range.

So these numbers say that M230 is not a direct replacement for 25mm M242 Bushmaster, let alone Mk44 Bushmaster II 30mm.

Development of M230LF

ATK started the development of a new variant of M230 chaingun aimed at ground and naval platforms. It is called M230LF with LF stands for LinkFed.

The development effort concentrated on the following changes & improvements:

• Link-feed ammunition to enable conventional belted ammunition usage and simple ammo cans
• Increased barrel length to enable higher muzzle velocity
• 24V DC electrical operation required for ground platforms
• Hang-Fire protection to improve manned turret safety
• Rate of fire better suited to land and naval applications

So how best M230/LF can be best employed?

Although 30x113mm ammunition is a member of the Medium Caliber Family, it is located at the lower end of the spectrum in terms of lethality.

However, M230 is a  compact, lightweight and low recoil cannon.

As you can see from the image, M230LF has a total length of around 2.2m. 

• 25mm M242 has a total length of 2.6m
• 30mm Mk44 has a total length of 3.4m

In terms of weight:

• M230LF total weight: 72.6kg
• 25mm M242 total weight: 119kg
• 30mm Mk44 total weight: 156kg

Recoil force:

• M230LF Recoil:  7.34kN (Naval)/ 28kN (Ground)
• 25mm M242 Recoil: 40kN
• 30mm Mk44 Recoil: 35.6kN

Looking at the values above, it seems M230LF can be a good alternative for light turrets and Remote Weapon Stations that are armed with:

• 12.7mm/.50 cal M2 Heavy Machine Gun
• 40mm Mk19/GMG Automatic Grenade Launcher

In that case, the main reasons/advantages will be:

• M230LF's high lethality and longer range compared with M2/Mk19
• M230LF's straight trajectory compared with Mk19's high trajectory
• M230LF being an electric driven gun that does not need any fancy mechanisms such as trigger solenoid and cocking actuator
• Frontal case ejection that makes it easier to integrate in a turret
• Lower weight, smaller dimensions and lower recoil enables light turrets to be developed. This also provides light platforms packed with higher fire power.

However, M230LF also has some drawbacks when compared with M2 & Mk19

• Apparently higher initial cost
• Comparably higher weight that limits man portability
• Lack of tripod operation in case of removal from the turret or platform.

The images below shows some applications of M230LF:

Mk51 Weapon System onboard LCS

M230LF would be a very good capability to upgrade the firepower of some platforms such as:

- US Marine Corps AAV7 Amphibious Assault Vehicle

- M1117 4x4 Armored Security Vehicle

- M113 to enable more firepower than the current .50cal cupolas

- M-ATV

- M1126 Stryker 8x8

in 1-Man and remote turret designs.

Textron's 1 Man Turret Concept with M230 ChainGun

CMI's CPWS with M230 ChainGun

Eurosatory 2014

ATK's 7.62mm Chaingun is type classified by US Navy!

The 7.62mm Chaingun from now on to be known as Mk52.

I have posted a detailed article on the 7.62mm ChainGun:(http://warfaretech.blogspot.fr/2014/02/762mm-chaingun-from-atk.html)

I found the opportunity to see the weapon first hand.

The gun is even more compact than Ive seen from its photos.

The empty cases are ejected from the front of the barrel. This eliminates an important complexity for turret integration.

The gun does not need a mount in the conventional sense. The clamp to the front reciever is the mount. There goes another complexity for turret integration. It does not require a complex, machined mount with a high manufacturing cost. I dont even consider the weight of the conventional mount.

The barrel can be changed from inside the turret by lowering the bottom part of the reciever thru its hinge.

If ATK can drop the price of the gun to a lower level, I believe we are looking at a must have equipment for a turret or RWS.

ATK Bushmaster III Automatic Cannon

Bushmaster III 35mm Cannon

For today's threats as well as future's??

Bushmaster III is the biggest and baddest member of the Bushmaster Chainguns that is available for integration. Although there is Bushmaster IV 40mm cannon, it is, as far as I know, in prototype stage.

Bushmaster III is a electric driven, link-fed automatic cannon that can be employed either as a 35mm or with changing the barrel and forward feeder assembly can chamber SuperShot50, 50mm ammunition. There are some works going on for the linkless feed Bushmaster 35mm; however the in-service guns are link-fed.

The specification for the Bushmaster III is roughly:

In order to better see the differences between 25mm M242, 30mm Mk44 and 35mm Bushmaster III, here is a short comparison:

And here is another image that compares the sizes of M242 25mm, Mk44 30mm and Bushmaster III autocannons:

Just looking at the size difference between the M242 25mm Bushmaster, you can see that Bushmaster III is a monster.

However, this monster has also quite a strong bite as well!

Let's look at the High Explosive (HE) ammuntion:

The 25mm HE projectile has a mass of 180 g.

The 30mm HE Projectile has a mass of 362 g.

The 35mm HE Projectile has a mass of 550 g!!

Just look at the HE difference and imagine the destructive effect of the 35mm HE!

For an IFV vehicle, the real bite of the gun comes thru the armor piercing capability versus armored threats.

The lethality performance against armor plate is usually expressed when the projectile is not hitting on a vertical plate, but impacting on a sloped armor as shown in the image below. The commonly accepted method is expressed as 60 degree obliquity.

 

    

 Now keeping this information in mind, the graph below shows the penetration capability of 25mm, 30mm and 35mm Armor Piercing Sabot rounds:

Some highlights from the graph above:

i. 30mm has ~30% more penetration than 25mm.

ii. 35mm has ~60% more penetration than 25mm.

We should also keep in mind that:

i. 25mm AP round tracer burns-out at around 2000 meters, thus seeing fall-of-shot beyond 2km becomes really difficult.

ii. Due to trajectory and velocity decrease, 25mm round's accuracy drops down considerably beyond 2km's.

iii. However, with the 35mm, accurate firing beyond 3km is possible and proven by the Dutch gunners from CV9035 in Afghanistan.

In terms of lethality, 30x173mm caliber is performing quite good against today's battlefield threats like BMP-3.

However, TNO's 30mm vs 35mm comparison document states that:

One other important issue for Bushmaster 3 turret integration is the ammunition capacity.

Before going into that, we should better have an idea of the size of 35mm ammunition. I believe this can help:

Now, getting back the issue of ammunition capacity:

i. Belted 35mm ammunition would be really difficult to handle during loading because of the weight and size of the belts of ammo.

ii. Linkless feed systems can be an appropriate alternative for 35mm feed systems. I will explain Linkless Feed later on.

iii. The number of ready to fire ammunition is very important, ie. CV9035 has a total of 70 rounds of belted 35mm ready-to-fire, which is not bad.

However, an IFV turret with Bushmaster III and 100 ready-to-fire rounds would be a real winner.

iv. For a turret that is armed with Bushmaster III, the First Round Hit Probability (FRHP) would be especially important. Because you no longer have an ammo capacity such as Bradley's 300 rounds of 25mm. So for 35mm, your fire control system should make every shot count! 

©2014 Warfare Technology

7.62mm ChainGun from ATK

Electric Driven Machinegun for Turret Applications

7.62mm ChainGun

From world.guns.ru/:

Following failure of the 7.62mm M73 tank machine guns, in around 1970, US Army decided to try some unorthodox solutions for a compact yet simple and reliable tank machine gun in the form of an externally powered weapon. 

An additional benefit of an external power solution is that such weapon, if properly timed, will not leak powder gases back into the tank interior. 

Initial work was commenced by the Hughes Tool Co, under contract to the US Army Weapons Command. The test weapon, unofficially known as EPAM (Externally Powered Armor Machine gun) used a 24VAC electric motor, which operated dual belt feeds and a rotating cylinder with cam slot that operated the reciprocating bolt. 

The test weapon fired at about 550 round per minute, and had forward ejection through a long tube, so spent cases would fall outside the tank interior. 

For various reasons, however, this system was abandoned in favor of the so called “Chain Gun” system, developed by the same Hughes Tool Co in around 1973. 

The basic principle involved an externally driven endless chain that ran around the receiver and operated a more or less traditional rotating bolt and bolt carrier through a single abutment, fixed to the chain. 

This principle was used to develop a wide array of weapons, including a 30mm helicopter gun for the AH64 Apache helicopter, several automatic cannon of the “Bushmaster” family, and one 7.62mm machine gun, the EX34. 

Despite the fact that “Chain Gun” automatic cannon found wide acceptance in US Service and abroad, the “smaller brother” of the family found no luck in the US Armed forces; however, it was adopted as a vehicle gun in UK and Canada and is manufactured under license by Colt Canada (former DIEMACO) in Canada. 

Also, in 2011 US-based ATK Corporation announced its newest addition to the “Bushmaster” family of externally operated weapons, the “Bushmaster 7,62mm” tank machine gun. 

This weapon appears to be modified and slightly shortened and lightened version of the old “7,62mm Chain gun”.

This is  an image showing the mechanism from an old report dated 1982 for the then called the Hughes Helicopter 7.62mm Chaingun.

Here is an image I've found from arcforums that shows a Hughes 7.62mm Chaingun on a AH-6E helicopter:

The British variant of the 7.62mm chaingun from the Challenger MBT is shown in the image below:

So this 'old' new gun is now offered again from ATK. 

So what makes this gun so special:

- It's been designed from the ground for turret applications. 

- It is electric powered and does not use propellant gases or recoil to drive the bolt

- This means you do not need fancy and complex electric chargers for your turret application. That eliminates one important problem.

- It has got a belt pull force in excess of the link strength; which means you can put a huge ammo box say 1.000 rounds in your turret and you dont need a powered forwarder to assist the gun. That eliminates another problem.

- The spent cases are ejected automatically to the outside from the frontal eject port. There goes another pain in the a** for the case collector or case eject chute.

- The gun is mounted using an easy to implement bayonet mount and does not need any recoil absorbers or soft mounts. So you dont need a fancy gun mount.

-You can change the barrel from inside the turret which is another nice feature

- There is much less fumes blown inside the turret compared with the gas operated guns.

- And this gun comes in a package that weighs only 15kg's.

It seems these advantages for turret applications was notified by Norwegians and Hagglunds of Sweden 'cause the new CV9030 for Norway comes with the 762mm Chaingun as seen below:

©2014 Warfare Technology

ATK LW25 Cannon

ATK

Light Weight 25mm

LW25 Weapon

ATK's LW25 is a 25mmx59 caliber externally driven electric cannon.

It's total weight of 30.8kg makes it an attractive alternative to M2 .50cal (38kg) machine gun and Mk19 40mm (31kg) grenade launcher for Remote Weapon Station applications.

 

LW25 on Saab's Trackfire RWS

From ATK's website, the features are listed as:

Dual-feed system. The dual-feed system provides the user the flexibility to select between two types of ammunition, depending on the threat situation and desired lethality. This affords options when faced with difficult rules of engagement that require quick transition between a lethal and nonlethal response. Next-round-select capability enables users to switch between the two feeds, with the next round fired being the newly selected ammunition.

Increased lethality. The LW25 includes a robust family of ammunition that is compatible with ATK’s Programmable Air-burst Munition technology. The PABM round greatly enhances lethality over current legacy weapon systems with its ability to defeat troops in defilade. The LW25 offers a dramatic increase in lethality over the current M2 .50 caliber, M240 7.62mm, and Mk19 40mm Grenade Machine Gun.

High reliability. Due to its externally powered electric, chain-driven design, the system has a mean rounds between stoppages in excess of 35,000 rounds. This allows for prolonged use in diverse applications and difficult environments where performance and sustained firepower are crucial. Sluggish performance and constant stoppages are a thing of the past.

Remote or manned operation. Also due to its externally powered chain-driven action, the gun can be fired remotely from weapon stations while the crew remains protected and under armor, without the need for charging and manually clearing stoppages. This is particularly important for applications such as MRAP, where gun access and system reliability demand such flexibility. The gun system has been integrated and fired from the Common Remotely Operated Weapon Station and can be employed in manned applications on ground, naval and helicopter aviation platforms.

Compact lightweight system. The LW25 is a compact and lightweight design based on the highly successful Bushmaster family of Chain Guns. This combat-proven design allows for ease of use and leverages more than 25 years of engineering expertise. The LW25 is ideal for lightweight applications currently limited to gas-operated guns.