Titanium cartridge cases?


#1

OK, all you metalurgists out there - here’s an easy Q for you.

A friend said that he has a couple of 30mm cases and he thinks one of them is aluminum and the other is titanium. He asked if I knew how to tell the two metals apart. I told him I knew just about everything, but that wasn’t one of them. I know that there were titanium cases experimented with for the 30mm, and maybe even issued ??

So, is there any way to tell? When I look at them I want to appear smart.

Ray


#2

Hi Ray
According to my husband again Titanium will weight alittle over 50% more than Aluminum. Also Titanium will be very silvery in color, but weighting them may be the best way
Carolyn


#3

Ray,

If the two cases are otherwise identical, the difference in density of the materials could be a clue. Aluminum is 2.70 gm/cc and titanium is 4.51 gm/cc nominal (no alloys). On the other hand, if someone went through the expense of using titanium for a cartridge case, they would likely take advantage of it’s increased strength and make it thinner at the high stress areas (case head) to save material. Thus weighing them may not tell you what you want to know unless you determine their volumes. That’s not too hard to do but may be more trouble than you’re up for.

Dave


#4

Carolyn - Dave

Thanks. I knew (Google told me) that titanium was 50% heavier than aluminum and thought about weighing the cases. But, as Dave said, the titanium cases would probably have thinner case walls to take advantage of the stronger metal. If so, then the titanium case could actually weigh less.

Google also said titanium had a “lustrous” appearance but I’m not sure exactly what that means. Brighter? Shiney?

Ray


#5

Ray,

A process that may work to measure the volume of the case would be to put the case in a container of water filled to the point it overflows-then remove the case and measure how much water is required to refill the container to overflowing. This will give you case volume. Lots of variations on this process. Should work for something the size of a 30mm case. harder to do with a 9mm case.

I do have an FN 9mm load with a Titanium case. I was told by Peter Labbett that at RG he had seen a 30mm Aden case make of Iridium!!! Costs more than Gold!!! Would like to see the objective of that test.


#6

Ray
Here is some more info for you. Titanium is slightly magnetic so maybe you could feel some pull from a magnet and it’s also a poor conductor of electricity as compared to Aluminum, so this he is kind of guessing at this part, take a ohm meter and seeing if there is a difference in readings.
Carolyn


#7

Now that this discussion has taken a turn into electronics, it is becoming a little too technical for me. Ray professes to know about everything, so he may know what ohms are, and that they even make a meter for measuring them. I generally make a point to avoid trying to measure things that I can’t see, as its pretty much a given that I won’t understand them.


#8

Guy–Ohms are the unit of measurement for resistance to the flow of electricity. You can buy a cheap VOM (Volts-Ohm-Meter) at any Radio Shack for less than $10.00.


#9

I thought an ohm was something like a furlong. Only different.

When I was a young lad there was a girl who lived down the road from me named Mary Lou Ohm. The prettiest girl I had ever seen. She would have nothing to do with me. I’ve often wondered what Mary Lou looked like as a grown woman.

I don’t think my friend’s two 30mm cases are worth all that trouble. I was hoping there was a simple way to tell the difference between aluminum and titanium. I’ll try the magnet and if that doesn’t work . . .

Thanks for all the help

Ray


#10

Ray,
Do you suppose Mary Lou’s ever wondered how you turned out? I’ll bet she’s a lot prettier than you.

If the magnet doesn’t work, you and your friend might consider looking up Mary Lou and getting her opinion as to whether its aluminum or titanium…


#11

Measuring the specific electrical resistance would be very difficult and very subject to erroneous measurements. It only works with wires if you want to perform such a testing.

Unfortunately, titanium has no measurable magnetical properties so checking with a magnet would not work.

The best way to analyze metal objects like these is by atomic absorption spectroscopy but I presume you don’t have the apparatus and you have to take a monster of the case. However, if you can send me a monster (very small would be sufficient, about the size of a splinter), I can make such an analysis for you if you want.

The easiest way to determine the case material (if no alloy!) is indeed a density check. But you should measure the total case volume and not the volume of case + empty indise volume like mentioned above, if I read well. Fill a glass vase with water and a drop of detergent (to decrease the surface tension of the water). Mark the top of the water column on the vase and sink the case in the vase. Now mark the top of the column again and measure the distance between the lines. It’s an easy way to calculate the volume of the rigid case material. Now divide the mass of the case by the volume and you have the density. Compare that with the known densities of aluminium and titanium.

An alloy might be possible as well of course. Then any “household-method” measurement would be useless because the exact ratio of the alloy components must be determined first.

Feel free to contact me if the household method doesn’t work!


#12

Guy

I doubt if Mary Lou has EVER wondered about me and how I may have turned out. As far as she was concerned, I didn’t even exist. But, since she dissed me, I hope she is/was ugly and mean.

OTOH, my wife turned out OK. I met her when she was 13, cute and freckly, and she has only gotten better looking.

Thijs

As I said, those 30mm cases aren’t worth that much trouble. I’ll look at them and report back.

Ray


#13

My simple contribution is that your friend probably has two cases with different anodized finishes and for whatever reason, thinks that one is titanium. A simple weight check will tell you all you need to know I think. A visual inspection of markings will probably help too. I would think that a titanium case would be only in the realm of the very experimental and not subject to many, if any markings at all. Like my wise old father says: “If it sounds too good to be true, then it probably isn’t.”. I think that any titanium cartridge case is too rare to just turn up unexpectedly.

Of course, I could be wrong…

Anxiously awaiting to hear the results of your investigation.

AKMS


#14

OK for my two cents, if you have a region that is open to inspection just drop a few drops of Concentrated draino (Lye) solution and if it fizzes it is aluminum, but wash it off fast or there will be a hole in the Aluminum real fast, (minutes). Vic


#15

Vic

I learned the hard way about caustic soda (lye) eating aluminum. Not with cartridges but with guns.

All

Well the mystery is solved. They were both aluminium. One was polished which made it look different.

But thanks for all the responses. I know that I learned something new. Now if I can just remember it. ;) ;)

Ray


#16

A fast and relatively inexpensive method to tell the difference between a titanium and aluminium (or aluminum) case is to X-ray it. The aluminium case will be very faint or almost invisible on X-ray (except for the primer) while the titanium one will be readily visible. And you don’t have to wet or otherwise damage the cases.


#17

An example:

The fourth case from the left is an aluminium CCI case (either from a 9mmP Blazer cartridge or a 9mmP shot cartridge)


#18

If somebody has two cases of the same dimensions, one brass and the other confirmed titanium, I am happy to X-ray those for you and provide you the imaging if you are willing to ship the cases to me in London. We can then get a handle on the radiological appearances of the two.