Wednesday, November 8, 2017

Is the recoilless rifle making a comeback?


I'm sure military veteran readers will remember recoilless rifles such as the US M18 57mm., M20 75mm., M67 90mm. and M40 105mm. weapons (six of the latter being mounted together on the famous M50 Ontos);  the Swedish Carl Gustav 84mm. (still in front-line service today, in upgraded form);  and the British Wombat 120mm.  Despite being called 'rifles', they were actually small artillery pieces.  The Soviet Union developed its own equivalents.

Most such weapons have fallen into disuse with the development of guided missiles, but now comes news that a modern version of a recoilless rifle - actually semi-recoilless, if I understand the article correctly - is under consideration for use aboard lighter armored vehicles.

This technology is called RAVEN, which stands for Rarefaction Wave Gun.

The operating principle behind RAVEN is similar to older recoilless guns, in that a limited amount of propellant gas is vented backwards in order to mitigate the recoil force of shooting a projectile. However, unlike recoilless guns, which lose velocity relative to conventional guns, RAVEN guns retain the same velocity and power as a conventional gun while reducing recoil forces and erosion to the gun. This makes this ideal for light vehicles, as the cannon itself can be made from lighter materials, and the vehicle does not need to “dig in” with a spade to stabilize itself before firing.

. . .

Unlike earlier recoilless guns, the chamber in which the propellant and cartridge is placed is sealed at the beginning of the combustion cycle. After ignition, but before the projectile has reached the end of the barrel, the combustion chamber opens and starts venting gas. This venting of the gas gives RAVEN guns their recoilless properties, as the mass of gas leaving the gun by moving backwards compensates for the mass of the projectile moving forwards. This venting of the gas creates a drop in pressure, which then propagates down the gun barrel. This is the eponymous rarefaction wave. The wave then helps propel the projectile down the barrel, allowing it to leave without any loss in velocity. The early venting of the gas means that the materials that comprise the gun heat up less, allowing the gun to fire faster without overheating. This synergizes with the possibility to make guns of a lower weight, due to the recoil reduction granted by RAVEN technology.

. . .

Overall, RAVEN guns present an interesting, high-caliber armament option that could provide America’s next generation of light vehicles the firepower they need to overmatch any current and future threat. While the technology is not yet mature, it is based squarely on concepts already understood and developed.

There's more at the link.

It appears that 35mm., 45mm. and 105mm. versions of the RAVEN cannon have already been successfully tested, and further development is ongoing.  The 105mm. version is illustrated below (click the image for a larger view).




If the technology can be perfected, we may yet see a ballistic equivalent to the M1 Abrams' 120mm. cannon, mounted on a platform weighing half as much, and much more mobile.  That would please organizations like the US Marine Corps, as it would be easier to land lighter vehicles like that from the sea, if necessary.

Peter

10 comments:

Aesop said...

Playing with the toys as brochure-bait and prototypes is nice.

What would be nice, for both the Marines and the airborne, would be actually fielding some actual numbers of APCs with these lighter pocket-gun mounts.

While they've been yakked about since forever by contractors trolling for a contract, to actual serving troops, they're nothing but 40-50 years of vaporware.

Jonathan H said...

The big drawback of recoilless rifles, and these units as well, is the amount of exhaust gases produced, especially by large caliber ones - it is why they are used int eh open, and mounted on the outside of the vehicles.
If you follow links to the picture of the 105 firing, the ball of flame behind it is as big as the ball out the muzzle; their design calls for an auto loader because this weapon couldn't be mounted in a turret, manned or unmanned, due to heat, pressure, and flame front issues. It MIGHT be able to be mounted on top of a vehicle like the gun on the Stryker MGS is.
The Russian/ Soviet tanks with an auto loader have a fixed minimum reloading speed and limits on ammunition size and capability due to a 1 piece system. The US has not fielded an auto loader in the past because manual loading can be faster and because the use of 1 piece tank ammunition gives flexibility, such as allowing for longer kinetic energy penetrators than 2 piece ammunition does.

Personally, I think a better choice is to use a lightweight conventional gun for large calibers instead of a more complicated system like this one.
As for the small calibers, a 'semi-recoilless' system like this could allow for mounting of larger caliber weapons on relatively small vehicles IF the vented gases and flame front could be directed and controlled.
At this point, this is just barely beyond vaporware, so I'd wait to see lots more actual testing before supportin git.

McChuck said...

The recoilless rifle is back in action with US forces. The Carl Gustav 84mm M3 and M3A1 (M4 in Sweden) passed testing and field trials, are in service and in the procurement system. (M4 is currently approved for SOF only, but is expected to be for general release next year.) CG m4 is only 15 pounds, has a 1500 meter range (depending on round), and has about a dozen different rounds to choose from. This includes a programmable air burst HE-frag.

This is what finally killed the XM25 fiasco. It's cheap, it's simple, and it works.

McChuck said...

From Wikipedia:
In November 2011, the U.S. Army began ordering the M3 MAAWS for regular units deployed in Afghanistan. Soldiers were being engaged with RPGs at 900 meters, while their light weapons had effective ranges of 500–600 meters. The Carl Gustaf allows airburst capability of troops in defilade out to 1,250 meters, and high explosive use out to 1,300 meters. While the weapon provides enhanced effectiveness, its 9.5 kg (21 lb) weight burdens troops. On 28 March 2013, USSOCOM announced a call for sources to develop a kit to lighten the M3 MAAWS and reduce overall length without affecting handling or ruggedness. By that time, Saab was developing a weight-reduced version prior to the SOCOM release that demonstrated no decrease in performance, no increase in recoil, and nearly equivalent barrel life that could be ready for government testing in 2014. Saab has also developed a new high explosive round that has a direct fire range of 1,500 meters when using a fire control system.[8]
M4 variant

At AUSA 2014, Saab Dynamics displayed its new Carl Gustaf M4 variant. Compared to the M3 MAAWS, the M4 is 3.4 kg (7.5 lb) lighter weighing 6.6 kg (15 lb) and shorter with a 950 mm (37 in) overall length. The shorter length was in response to the need to wield the weapon in urban terrain, and weight savings were achieved through using lighter components whenever possible including a carbon fiber tube with titanium liner, as well as a new venturi design. Other new features include a red-dot sight, a travel safety catch to allow the M4 to be carried while loaded, an adjustable shoulder rest and forward grip for improved ergonomics, a shot counter to keep track of how many rounds have been fired to manage the weapon's 1,000-round barrel life, picatinny rails for grips and sight mounts, and a remote round management function so intelligent sights can "talk" to programmable rounds.[9][10] The Defense Department agreed to evaluate the shorter and lighter M4 version over the next two years;[11] testing and qualifications were planned to be completed in spring 2017, and the weapon type classified as the M3A1 in fall 2017, making the system available for procurement to all Department of Defense services.[12] The first unit is planned to be equipped with the M3A1 in 2018.[13]

McChuck said...

News excerpt from yesterday:
Military.com | 7 Nov 2017 | by Hope Hodge Seck

The Marine Corps is getting ready to equip every infantry squad with a Carl Gustaf recoilless rifle for added range and firepower.

And further out, officials are weighing the possibility of swapping out the Shoulder-Launched Multipurpose Assault Weapon, or SMAW, in combat engineer squads to give troops more options for busting enemy bunkers.

The Corps is planning to collaborate with the Army to purchase the M3E1 Multi-Role Anti-Armor Anti-Personnel Weapons System, or MAAWS, a new version of the 84mm Carl Gustaf made to be lighter, more compact and easier to wield, Chris Woodburn, deputy for the Marine Corps' Maneuver Branch, told Military.com.

While the Army and U.S. Special Operations Command have used previous versions of the Carl Gustaf, it's a new weapons system for the Marine Corps.

"Right now, we have a registered capability gap for multiple-effects rocket fire," Woodburn said. "So the Army and SOCOM have the MAAWS, and we are looking to get the resourcing we need to pursue the next iteration of MAAWS."

The service expects to field one of the recoilless rifles per squad, he said. The weapon will not replace any existing elements of the squad, but will function as an additive capability for any squad member to operate.

Teaming up with the Army will allow the Corps to purchase the MAAWS at lower cost, said Kevin Finch, product director for the MAAWS at PM Soldier Weapons at the Army's Picatinny Arsenal.

Finch said he expects the Corps to order about 1,200 of the weapons, a number roughly equivalent to the Army's planned purchase of 1,111 M3E1 rifles.

The Army plan would contract for the weapons this fiscal year and begin fielding around 2023. The Marine Corps could "jump on board" and join the contract by 2019 or 2020, Finch said.

Old NFO said...

Simple is better in combat. The more moving parts, the greater the failure rate or inadvertent jamming...

RHT447 said...

Ah, memories. I was trained to repair both the M-67 and the M-40 in Small Arms Repair School. Indeed, the back-blast of these weapons was a bane. When fired at night, EVERYBODY knew what you were and where you were.

Theother Ryan said...

I believe we are putting Carl Gustavs in normal Infantry platoons (vs currently just rangers an sof). Can't say about this new one.

buscaraons said...

Golly and to think the Canadian military has been using the Carl Gustav since the 70s. Nice to know that our military bureaucrats aren't total doofuses
xavier

Anonymous said...

Yes BUT: The lightweight gun will lead to a light tank or glorified APC (think striker) that can be destroyed with a WW2 75MM main gun. Heavy armor is heavy for a REASON. For decades the fumble factory has preached "lighter is better". But light tanks and armored cars that run up on real tanks ALWAYS come off worse for wear.--Ray