15.5x105?


#1

Can anyone please confirm if this one is a 15,5x105 from the Belgium? The driving band appears to be black translucent plastic, also the tip of the bullet appears to be plastic.
What about the cut in the base? It does not have a hole so I don’t think it was a crusher…
Anyhow, any info on this caliber and round is appreciated.


#2

Correct, yours is just not an APDS but an APHC.
The driving band is actually translucent but it got covered with paint when laquered.


#3

Here is the other variation with a white plastic cap.

I have a couple of cases that have a notch cut in the rim but without a sidehole for crusher tests. I don’t know if these are legitimate (yours appears to have a proper neck crimp) or assembled by someone who had access to components.

This is an interesting case type with a number of distinctive characteristics that speak to the evolution of the design. The first loadings have headstamps and an angular extractor groove.

The next step with modified h/s bunter and extractor groove which now has a radius.

The final version has the rounded extractor groove and no h/s.

The program was cancelled in the the early 1990’s.


#4

Super nice rounds! Can someone tell me what “Crusher” means in relation to ammunition? Major novice here :-)

Jason


#5

To measure the amount of chamber pressure generated when a cartridge is fired, a device known as as a C.U.P. Pressure test gun used to be used. This special gun had a device that went on top of the chamber over a small piston that aligned with a hole in the side of the case. Pressure Test cartridges usually have a slot or marking of some sort to enable them to be aligned with the piston when inserted in the Test Chamber. A small cylinder of a copper alloy (the ones I have are 0.244 x 0.432 inches), called a Crusher, are placed in a chamber above the piston. When the Test cartridge is fired, the copper cylinder is “Crushed” by the pressure. A table preovided with that lot of Crusher Cylinders can be consulated to detemine the pressuere generated by the amount that the Crusher is deformed.

C.U.P. Testers are little used today. Most pressure testers use a piezoelectric stain gauge. It is more accurate and easier to use.


#6

Thanks for your answers gentlemen!


#7

Really apreciate that explanation, Ron. Thank you very much. You guys really know your stuff!

Jason


#8

C.U.P. stands for Copper Units of Pressure. After I wrote the above explanation, I found a more through description on the web at:

chuckhawks.com/pressure_measurement.htm


#9

Thanks again Ron. Really great, detailed explanation. Now I get it :-)


#10

I don’t “do” material of this nature, so the APHC nomenclature is new to me - “Hard Core” or something like that?

.


#11

Iconoclast, correct, as far as I have observed it is applied on Tungsten-Carbide cored projectiles but the designation is not consistent throug the NATO etc.
Does anybody know why?


#12

Here are a couple of pressure test rounds for the 15x115 and 15.5x106 program.

The top round is the 15.5x106 and the other 2 are 15x115 (steel cased, which was made in very limited numbers). The middle round has been fired, cleaned and reloaded. Note the gas leakage.


#13

Thank you very much, Paul, for the additional beautiful photos. Much appreciated!


#14

Nice pics and info Paul!
Do you have any clue as to why my round has the notch cut out but not a hole? Mine is unloaded, but the projo sits tight in the cannelures.


#15

It’s impossible to say. Were such rounds made up in the factory using scrap pieces, such as incomplete pressure test cases? Or, did someone who had access to components simply cut a notch in the rim and seat a loose projectile into a previously unloaded case? It is an odd combination. This type of projectile is much less frequently encountered than the standard ‘ball’ projectile.


#16

Paul, could you please post a perpendicular view of the head of your brass cased one?


#17

[quote=“EOD”]Iconoclast, correct, as far as I have observed it is applied on Tungsten-Carbide cored projectiles but the designation is not consistent throug the NATO etc.
Does anybody know why?[/quote]
Possibly because different languages result in different initials. After all, not even NATO is a consistent designation: to some member countries, it’s OTAN.


#18

[quote=“Tony Williams”][quote=“EOD”]Iconoclast, correct, as far as I have observed it is applied on Tungsten-Carbide cored projectiles but the designation is not consistent throug the NATO etc.
Does anybody know why?[/quote]
Possibly because different languages result in different initials. After all, not even NATO is a consistent designation: to some member countries, it’s OTAN.[/quote]

Yes, in particular to a not English speaking one…


#19

Hi Fernando,

Here are the pictures of the base. As you can see, the notch is obviously cut by hand and is, I think, 2 hacksaw blades thick.


#20

Thanks, Paul! That’s what I wanted to check out.