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Any info on this 30mm?


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Premium Member
Stamps on side of projectile read;



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By the case ID, I would venture the Hispano-Suiza 831 gun 30mm X 170mm, loaded in 1979.

The modified most recent version of the gun is known as the Oerlikon KCB. As I understand it, the KCB was further modified to become the Rarden. (From "Rapid Fire" by Tony Williams)
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French manufacture. MR stands for:Manufacture de Machines du Haut-Rhin, (Manurhin), Mulhouse-Bourtzwiller, France .
Used for the Hispano Suiza HS 831 (later know as the Oerlikon KCB) cannon.

Regards, Cornman
I was led to believe that the Rarden was based on the Hispano HS 831L cartridge that after acquisition by Oerlikon Buhrle became the Oerlikon KCB round. I thought Manurhin in France made components for the UK in the early years of the rarden which were assembled in the UK as rarden rounds. But this case has an odd taper at the base, odd crimping and drive band. Why should there be a different design between a 1945 Hispano 30x170mm case (below) and a say a 1970's case? Is a 831A different fron a 831L?


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Everyone is always looking for a better, faster, more accurate gun. So they tinker with designs for certain applications, and specific ammo for different applications. The ammo is not interchangeable between the 831, KCB, and Rarden guns. The 830 gun came first followed by the 831. As I understand it, the 830 had steel cases, whereas the 831 had brass. The Rarden was designed to work in an AFV with a slower rate of fire, and used brass cases, where the goal was to get the best acccuracy, and brass gave a better seal in the chamber. The KCB was utilized as an AA gun with faster rate of fire. During development, it is very common to experiment with case materials to evaluate performance. Steel is stronger than brass and is more often used for the more rapid firing guns. You seem to have examples of the 831 in brass, but you can see the bad extractor marks on your most recent photo. I believe you have a small run brass 831 case.
The KCB round is authorised for use in the Rarden gun and i have Quite a few Rarden cases with KCB extraction marks on them so KCB rounds and Rarden rounds are interchangeable if need be. My point is the round shown in my first post is quite different from Rarden, KCB and 831L.
Lets rephrase my question. Does anyone have any info on HS 831A rounds?
An extract from Jane's Ammunition Handbook (2009/10 edition, not yet published):

When originally produced, the series of 30 mm automatic cannon now generally known as the Oerlikon Contraves 30 170 KCB series was designated the Hispano-Suiza HS-831 series. The designation was officially changed when Hispano-Suiza became part of Oerlikon Contraves AG but is often retained. The 30 mm cannon design involved was virtually a scaled-up version of the 20 mm HS-820 (now known as the Type KAD) cannon and has been produced in several forms.

Two different loadings of the 30 170 have seen service. The original type was for the HS-831A gun, used only by France (in the AMX 13 SPAAG) and Saudi Arabia (AMX 30 SPAAG). These were mainly brass-cased, and used heavy shells with a conical ogive and a brass driving band. Muzzle velocity was 920 m/s. Most production is for the slightly modified HS-831L: this uses steel cases with lighter shells having a more conventional ogive and sintered iron driving bands. Muzzle velocity is 1,080 m/s. The two types are not interchangeable due to the different ballistics.

RWM Schweiz's KCB ammunition family was used as the basis for the 30 mm Rarden gun ammunition family but ammunition for the KCB and Rarden L21 is not qualified as inter-operable.
Thanks Tony, thats the info i was after.

I was led to understand that quote;

" Official army documentation makes it clear that Oerlikon Type KCB 30mm x 170 ammunition may, if circumstances require it, be used in the Rarden weapon. Listed are the six natures of 30mm KCB ammunition (then manufactured at the old BMARCo plant in Lincolnshire) that were shown as being suitable for Rarden use. These were:-
My information about the lack of qualified interoperability came from the people at Radway Green who make the Rarden ammo. I suspect that the difference lies in the meaning of the word "qualified", which in NATO terms requires a battery of tests to be passed. I can believe that the ammo will in practice be interoperable, it's just that it hasn't been through the formal qualification process.
30mm. HS? round.

Stamps on side of projectile read;

Charlie, just a thought - could this be tied into the development of the Vickers/BMARCo. ''Falcon'' A.A. twin cannon self-propelled equipment ?? Regards, RonB. Development was late 50's - into early 60's.
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