30x136 Titanium case for HS 825.

The HS 825 was developed in the 1950's as a rival to the Aden however it proved to be unreliable and so was not adopted.
The attached photographs show several complete rounds. The case on the left is made out of titanium. Next to it is a drill round and then 3 different service rounds (all inert and empty of course!!).
If anyone has any further information on titanium cases I would be interested in seeing some photographs of them. These cases must have been extremely expensive to produce.
I've attached a photograph of one of the headstamps, interesting in that it is lot 1.
Dave.

There's a brief article on the HS 825 and its ammo coming in the March issue of The Cartridge Researcher. I'd not heard about the titanium cases though. If you send me a high-res version of that pic, Dave, I'll put it in the April edition.

Are you sure the case is made of Titanium? I can't see any reason for making such ones. The material is very expensive and extremely difficult to machine. I don't think it can at all be cold pressed to cases in process like brass is used. Hot pressing is possible but it must be done in inert gas protection because red hot Titanium is very sensitive to cracks caused by Hydrogen from air. Thus, maching from solid bar may be the only possibility, but again, what would one gain using Titanium instead of brass or steel?

Hi T mine, yes I'm sure it is.
Dave.

OK Dave, I believe you. But do you know the reason why it is?
Can you compare weights? Titanium case should weight roughly of similar steel case. As Titanium is much stronger the case could be made even thinner walled and reduce the weight more.

Hi T mine, thanks I'll weigh it and let you know.
I sent you a separate PM on this with a bit more detail.
Dave.

Sectioned titanium case

Hi, I've not got around to weighing it yet but I've just got hold of the half sectioned case that came from the same place, it too is titanium.

The interesting thing about this is it looks like some sort of hardness tests have been done on it, part of the section of the base has been gridded and each grid has a small indentation in it.

Can any of you engineering/metal experts add to that theory please, I may be completely wrong with that idea?

Dave.

Obviously hardness tests have been carried out here. For what, I have no idea. As far as I understand such detailed hardness tests are used with heat treated metal only, and in my opinion titanium's properties do not change particularly if heat treated or not.
Could this test be just another waste of money and efforts as the whole idea of making casings from titanium.:questionmark:

When metal is drawn or compressed in other ways it is changing it's density. Once the case here is made of titanium it might have been of particular interest how the density structure had changed in such a case since it seems noone else had such data before (or did not share).

The USSR also once tested titanium cases for their R-23 gun in 23x260.

Hello,
I'm intrigued by this post as I've never heared of a titanium case before. The only reason that it attracted my attention was that a few years ago, a good friend of mine who is a long distance HGV driver was asked to bring a load of scrap titanium from somewhere in Europe to the UK for re-cycling. One of the pieces of scrap, (I believe from an aircraft), stuck out from the end of his 40 footer by about 12 inches, which is not permitted, so he decided to cut off the offending piece. After wearing out three hacksaw blades he was informed by a fellow driver that the stuff was stronger than hacksaw blades. According to him he had to ditch the entire length of metal before bringing the load home.
I can't understand why a titanium case would be made, disregarding the cost, what sort of pressures would they be looking for, and what sort of barrel would be capable of withstanding same?
Excuse my ignorance in these matters, I'm no expert but very curious?
Cheers,
navyman.

The proposed use of titanium was more likely down to its thermal expansion properties. The coefficient of linear expansion for brass is about 19 (micron/m K), for stainless steels 15-17, and for Ti about half that, at 8.6. In a single barrel large calibre (compared to most small arms) machine gun, where the breech temperature can rise very rapidly, a cartridge case made from a low coefficient material would reduce the probability of jams, and so increase the reliability of the weapon.

When any new material is trialled, there tends to be a good reason for it. Whether there is/was any performance benefit vs cost of titanium over brass or steel seems to have been ultimately answered by the adoption of the more standard metals.




Tom.

Thanks for your replies to this thread guys, interesting theories and very close to the mark.
This case and the half case came from a well respected old collection and following an article that I put in the ECRA journal I was put in touch with a guy who wanted to speak to me about it. I received a phone call and it turns out he worked on the manufacture of these cases!! Result!!
The idea of making the cases was not to fire them but to see if it was possible to make the titanium cases in the first place. From what I understand titanium forms an alloy very easily with other elements and so the manufacture of the cases had to be done in strictly controlled conditions to avoid cross contamination.
I am aware of titanium cases in a very large and well known collection in America and along with the 23x260 RH-23 round mentioned in above (thanks EOD) it would seen a few countries tried to make them too.
Dave.

Thank you all for the replies to this most interesting thread,
My goodness Snufkin, I'd completely forgotten about the coefficient of linear expansion since leaving Pompey Grammar for the navy in 1965! You have opened a chapter of memory that was long lost!
I look forward to hearing any other views on this subject.
Cheers all,
Guy.

I have a 26mm Colt AFV round from the 1960s which is also said to have a titanium case, although I'm not sure about that.

Tony Williams said:

I have a 26mm Colt AFV round from the 1960s which is also said to have a titanium case, although I'm not sure about that.

Click to expand...

Any chance of a photo please Tony?
Dave.

It's the 26x130 in this group from my Ammo Photo Gallery: