Semi-automatic or fully-automatic recoiless guns

[Rickshaw]

In several threads I've seen mention of experimental semi-automatic or fully-automatic recolless guns mounted on aircraft.

I've often wondered how these things work. The German Rheinmettal system with its frangible base in the cartridge case seems the most amenable to such adaptation. With it, it would be possible to design a revolver type weapon with the chambers moving into line with the barrel (and somehow mating with it and the breechblock with its venturi to prevent excessive gas leakage). The American system, with its multiple holes in the cartridge case sides seems less amenable and I've seen explanations using it where the mechanism moves the barrel (and chamber) forward, ejecting the spent case (or opening it for loading) and a fresh round is moved into place and the barrel (and chamber) then return to mate with the breachblock with its venturi and then firing.

Is there any more information on how the other various proposed weapons worked, if they are different to those two examples?

 

[Tony Williams]

The most recent attempt at an automatic RCL was the Mauser RMK project of the 1990s, originally intended to arm the German version of the Tiger attack helicopter. This used combustible-cased telescoped ammo (which looked like a simple tube), originally in a revolver cannon which was backwards-loaded (i.e. the ammo feed placed each round in front of its chamber, into which it was pushed backwards). Test firing took place on a land mounting, including on a Wiesel light tracked vehicle.

The initial version was in 30mm calibre but 35mm were also developed. To quote the "Updates to Rapid Fire" page on my website:

Mauser RMK development expanded to include four electrically-powered models, as follows:

RMK 30/2: 30x230 round, 280g at 1,050 m/s (round 44mm diameter, 500g), 4-chamber revolver, 300 rpm, 95 kg weight, 2.2m long (1.7m bbl)

RMK 30/1: 30x280 round, 280g at 1,350 m/s (round 50mm diameter, 655g), 3-chamber revolver, 300 rpm, 125 kg, 3.0m long (2.4m barrel)

RMK 35/1: 35x300 round, 400g at 1,250 m/s (round 50mm diameter, 900g), 3-chamber revolver, 300 rpm, 152 kg, 3.2m long (2.8m barrel)

RMK 35/2: 35x350 round, 430g at 1,480 m/s (round 63mm diameter, 1170g), single rotating chamber, 200 rpm, 280 kg, 3.5m long (2.8m barrel)

One proposal was to mount an RMK 30 on submarines in the Muräne (Moray) project: stored vertically in a waterproof housing at the end of a mast, so it could be elevated above the water at periscope depth. However, all of the RMK series have been shelved for lack of official interest.

 

[ouroboros]

Would the smaller 35mm type experimental RAVEN (rareification wave gun) work? It's a CTA rotating chamber type, so it can be as automatic as you want to be, though that isn't completely recoiless.

 

[CostasTT]

You might also want to take a look at these.
Link 1
Link 2

RPTR-37:

 

[Tony Williams]

Thanks for the links!

 

[CostasTT]

You are welcome. From what I read, the Russians found an interesting solution to autoloading recoilless weapons, namely having the barrell move forward to eject the spent case and load a fresh round before moving back to firing position - one of the methods mentioned by Kadija_Man.
And lest we forget the already mentioned 106mm proposed installation for the OV-10.
http://www.secretprojects.co.uk/forum/index.php?topic=344.45
http://www.secretprojects.co.uk/forum/index.php?topic=3048.0


There was also an automatic loading M40A1 turret developed for vehicle use. Source is Hunnicutt, I think.

 

[Petrus]

Oerlikon (?) automatic rocket launcher

There was an (semi?)automatic rocket launcher developed in the 1950s or 1960s in Switzerland, if I am not mistaken, by Oerlikon. It was proposed as an armament option for numerous AFVs of that time, mostly wheeled. As I've just found out, it was actually adopted by the Chilean army mounted on their MOWAG armoured cars (see attached pics).

Do you know more on the launcher (its principles of operation and so on)? Any information, esp. pictures, would be appreciated.

Piotr

 

[Tony Williams]

Re: Oerlikon (?) automatic rocket launcher

There was an (semi?)automatic rocket launcher developed in the 1950s or 1960s in Switzerland, if I am not mistaken, by Oerlikon. It was proposed as an armament option for numerous AFVs of that time, mostly wheeled. As I've just found out, it was actually adopted by the Chilean army mounted on their MOWAG armoured cars (see attached pics).

Do you know more on the launcher (its principles of operation and so on)? Any information, esp. pictures, would be appreciated.

Piotr

I have a poor-quality photocopy of a catalogue of the Oerlikon-Contraves weapon museum, which includes two entries on magazine-fed rocket launchers:

5 cm Raketen-Automat Oerlikon Typ 501 RA: a 50-rocket magazine, fired at 700 rpm. Developed 1954, intended for aircraft.

8 cm Zwillings-Raketenautomat Oerlikon Typ 3Z 8DLa: a twin launcher dating from 1964, intended for ships and AFVs. 9 rockets in each of two magazines, firing at 260-300 rpm combined.

(at least, that's a quick and dirty reading using my very sketchy knowledge of German!)

 

[CostasTT]

Re: Oerlikon (?) automatic rocket launcher

There was an (semi?)automatic rocket launcher developed in the 1950s or 1960s in Switzerland, if I am not mistaken, by Oerlikon. It was proposed as an armament option for numerous AFVs of that time, mostly wheeled. As I've just found out, it was actually adopted by the Chilean army mounted on their MOWAG armoured cars (see attached pics).

Do you know more on the launcher (its principles of operation and so on)? Any information, esp. pictures, would be appreciated.

Piotr

The launcher was also fitted to the Saurer/Steyr 4K3FA, the MOWAG Grenadier, Puma and Tornado, the HS30 and even the Nasty class PTF-13, among others.

 

[Tony Williams]

Yep, those photos make it clear that this was the 8 cm Zwillings-Raketenautomat Oerlikon Typ 3Z 8DLa. Actual calibre was 81mm. Elevation limits were -10 to +50 degrees.

 

[Petrus]

Thank you very much for information on the Oerlikon automatic launcher.
Having known its designation I found this: http://up.picr.de/5672636.pdf

Very interesting weapons system. Naturally it was being tested on many chassis (the Swedish Unimog-Landsverk armoured car was amongst them), but seemingly was used operationally only by the Chilean naval infantry. They deployed the rocket armed MOWAG Grenadiers during 'the war that never was', i.e. the Beagle canal conflict with Argentina in 1978/79.

Best regards,
Piotr

 

[CostasTT]

I'm not entirely sure if this is a revolver system or if the reloads are carried over the tube, but certainly looks like the former.
Made in China with an 82mm weapon.

 

[LVisingr]

80 cm Zwillings-Raketenautomat Oerlikon Typ 3Z 8DLa on wheeled chassis:

https://shushpanzer-ru.livejournal.com/2832975.html

 

[poky]

the Germans tested a 55mm recoilless gun during WW2, the MK115

 

[LVisingr]

Armoured Unimog with 80 cm Zwillings-Raketenautomat Oerlikon:

https://shushpanzer-ru.livejournal.com/2839457.html

 

[Tony Williams]

the Germans tested a 55mm recoilless gun during WW2, the MK115

Below (next to right-hand one) is my replica of the ammunition developed for the gun, from the Ammo Photo Gallery on my website. The beige part of the case represents the combustible element.

 

[marauder2048]

Would the smaller 35mm type experimental RAVEN (rareification wave gun) work? It's a CTA rotating chamber type, so it can be as automatic as you want to be, though that isn't completely recoiless.

It had a recoilless mode but with a ~ 20% reduction in muzzle velocity.
They did look at the larger 105mm version for a gunship but as with most of these efforts mitigating the
overpressure impact (thermal wasn't as bad as traditional recoilless) on aircraft skins starts to dominate.

 

[Grey Havoc]

There was also an automatic loading M40A1 turret developed for vehicle use. Source is Hunnicutt, I think.

Used on the BAT (Battalion Anti-Tank) variant of the M114, if I'm not mistaken.

 

[GWrecks]

Does anyone know if the Russell S. Robinson Model 14 would fall under a "recoilless" weapon?

http://otvaga2004.ru/kaleydoskop/kaleydoskop-inf/oruzhie-rassela-robinsona/ (Article in Russian I think)

Judging by the way it's held it at least seems like it would be near-recoilless. And I know that Secret Projects doesn't have a small arms section but it does get me thinking about what would happen if it did for things like this.

 

[TomS]

Does anyone know if the Russell S. Robinson Model 14 would fall under a "recoilless" weapon?

http://otvaga2004.ru/kaleydoskop/kaleydoskop-inf/oruzhie-rassela-robinsona/ (Article in Russian I think)

Judging by the way it's held it at least seems like it would be near-recoilless. And I know that Secret Projects doesn't have a small arms section but it does get me thinking about what would happen if it did for things like this.

We actually have a thread that mentions this in the Army Projects section.

https://www.secretprojects.co.uk/forum/index.php?topic=21593.0

Which includes a link to a more detailed narrative, here:

http://fnfal.com/forums/showthread.php?t=76174

Based on that link, the picture is not the Model 14, but the earlier developmental Model 2.

I would say it is not recoilless. To be considered recoilless, you'd need some sort of countermass (including gas venting) to counter the projectile recoil. The SR Model 14 didn't have a countermass system. It fired conventional 12.7 x 99 ammunition and used a "firing out of battery" mechanism to spread out the recoil between shots. So it gave a steady push while firing, not a series of jolts, but it definitely had recoil.

 

[Bob_Mackenzie]

Found one more pic of the Chilean MOWAG in service, 1978 near the Beagle Channel

(left background)

 

[kocovgoce]

Oerlikon automatic rocket launcher it is a rocket launcher that fires 81 mm rockets it does not use the principle of recoiless gun.

only the Germans managed to make recoiless gun that fired 55mm ammunition

​

 

[Scott Kenny]

The Mauser RMK system is what I'd use. Revolver cannon that's fed from the front of the cylinder.

I think that was the proposed system for the 75mm gun used in Gasaraki.