Unknown APFSDS Penetrators


#1

Hello everyone!

I got these just yesterday from a friend down in the US, I purchased some early M865 sabots from him and he gave me these with them. They where recovered from an AAI Corp building before its demolition. He was EOD for atleast 20 years and had an extensive collection, so I have no reason to believe these are “fake” or homemade. I have pictured them beside a standard 20x102mm dummy round for scale.

The black colored one seems to be made of some lightweight metal, it is very magnetic but lighter than a steel rod of the same size. Could possibly be hollow. It is also a few millimeters longer than the other and has a much longer tapered nose.

Measurements below
Weight: 7.0oz
Length: 9 1/2"
Fin length: 2"
Body diameter: 1/2"

The other one is much heavier and seems to be made of hardened steel or tungsten. It is ever so slightly magnetic so possibly an alloy, but much heavier than the other. The fin assembly is the same as the other dart, and both are press fit onto the body. The nose of this penetrator is stubbier and not as tapered as the other, and again slightly shorter.

Measurements below
Weight: 15.7oz
Length: 9 1/4"
Fin length: 2"
Body Diameter: 1/2"

Neither dart have the buttress grooves and are smooth. The fins on both are slightly off center from either other on both. They are very similar to this AAI 30mm experimental APFSDS penetrator with some slight differences however these seem much to big to be 30mm (Picture is of one currently for sale on Gunbroker from seller ORDNANCE.com). I would really like to know what these are from, so if anyone has any ideas, needs more pictures etc please let me know!
Rhys



#2

The items in question do look much like upscaled “flechettes” as they were used in cluster warheads/projectiles.
In recent years similar ones (CBU-107 PAW) were used by the US for special targets where colatheral damage was to be avoided (not using HE or fragmenting ammunition).

For APFSDS penetrators the darts do look too clumsy and unprecise.


#3

Thank you very much EOD, that makes much more sense. They didnt seem like any type of penetrators I had seen before and wondered how they would work.

Large flechettes make much more sense. I had never heard of the CBU-107 so thank you for teaching me! Very interesting and would love to see the effect it has. I have heard of the CMS Venom which is very similar.


#4

Yes, I wish we had seen some reports on the actualy use and effectivity.


#5

Is there any possibility that these are for something else? While the CBU idea does make sense, after having a chat with my friend, he mentioned he did find them with several 30mm APFSDS rounds with very similar designs. They where also found between 96’-98’ which could help narrow things down a bit.


#6

Going by the outer appearance there are at least 2 details speaking against a true APFSDS application.

  • The design and appearance are not what is required by an APFSDS design, means it is lacking precision in the fin section and the way it is attached.

  • A penetrator for an APFSDS application should have some grooves where the sabots are attached

It would be interesting to see those other 30mm you have mentioned.

Also not to forget that the penetrators as used in cluster warheads are also tested separately with improvised sabots in order to determine it’s effectivity i.e. penetration data etc.

Of course I am not saying that my assumption is the only correct one. Just going by what I see and know from other designs.


#7

Yes of course I understand, same here, not saying you are wrong just trying to figure out what they could be. I agree with the 2 points you bring up.

I dont have any photos of the 30mm, but from what I can understand they are very much like the photo I posted above, and this is all word from the guy I got them from. Fiberglass sabots and penetrator designs much like these 2 and the one above. He has however sent a photo of steel casings in the building, that have pressure testing holes in the casings, hence why the idea of an APFSDS rounds comes into play, I will post that photo when I can.


#8

I do see some similarity to the 20x102 flechette round i have. It was discussed here:
https://forum.cartridgecollectors.org/t/20x102-apfsds-flechette-round-info-needed/13460?u=orpheus72

Unfortunately, the original pictures seems to be gone, so i’m attaching them here again

It also has a similar shaped glassfiber inner sabot, and a non-grooved flechette, and the fin section is also quite rough constructed…
(picture of the dismantled one is not from me, so sorry, no better quality picture possible)

So i’m not saying it’s not a CBU flechette, but it could have been used for some kind of test in a 30mm sabot


#9

That is very similar Orpheus, nearly identicle to the 30mm I posted, however if these are in fact some type of discarding sabot piece I think it would be bigger than 30mm. I dont know the size of the penetrator in the first post I made but these penetrators would be a close fit in a 30mm case.


#10

Hello,

Very interesting!

I don’t know about a cartridge or bomb that may have been loaded with these penetrators, but they are certianly not the type used in the recent CBU-107/B cluster bomb (image down below). The latter was loaded with four different sizes weighing 590 g (20.8 oz), 86 g (3.03 oz), 5.5 g (1.94 oz), and 3,9 g (1.37 oz); first two have a tungsten penetrator and a diameter of .59" and .375", respectively, while the smaller ones are made of stainless steel (flechettes). They were made by General Dynamics.

Also, considering its weight and length, if these were intended for an APFSDS round, they would have been for a cartridge with a caliber bigger that 30 mm. For comparison, a Bofors 40 mm APFSDS-T penetrator weighs approx. 200 g (7.05 oz) and measures 200 mm.

For what it’s worth, by 1998 the only APFSDS type round produced by AAI was the 76 mm M464 APFSDS-T, so I assume that these are from an earlier era.

Thanks for sharing your find with us.

Regards,

Fede


#11

Fede, I did not say the ones in question were for the CBU-107. I just mentioned it as a design example.


#12

Alex, sorry, I was not trying to imply that you said that, just pointing out that they are not the type of penetrator used in that particular bomb.


#13

Fede, no need to be sorry. It was just for clarification.

I actually wonder if there were similar forerunners of the CBU-107. Maybe not for guided units but as heavy flechettes for defeat of aerial targets othern than “soft” ones. Means like lightly armored and unarmored vehicles, parked aircraft, facilities etc. Maybe in the 1950s to 1980s?


#14

Very nice pictures Fede, never seen them before but they are quite interesting.

As for the darts I have some type of anti-material flechette makes most sense. Like EOD said they are much to “rough” to be an accurate APFSDS round (as much as I would like them to be!).


#15

Sorry for bringing this thread back up, but I found the picture that originally made me think they where APFSDS darts (still not saying they are or are not). This round is from the experimental Colt CR-26 26x130mm AFV gun. While the design was never successful it was tested.


#16

I could be wrong but I think the various flechette payloads (anti- armor, anti-fortifications) that have been tested & employed with 2.75 inch (diameter) hypervelocity rockets need to be considered as a possible source of the kinetic energy penetrators (flechettes) shown at the beginning of this thread.

Some examples of such rockets-

Persuader hypervelocity rocket:

Inflight photo of Persuader 2.75 inch rocket just after release of kinetic energy penetrators (flechettes)

Specific information on the flechettes is proving difficult to locate. Some key reference links covering flechettes in the Wiki article below no longer work.

From the above article:

“…the WDU-5002/B FAT warhead, Flechette Anti-Tank, containing five tungsten-reinforced steel flechettes that could penetrate a T-72’s side and top armour at a distance of 10,000 feet (3,000 m). It was also found to be a useful warhead for use against medium and light armoured vehicles… Further development led to the WDU-500X/B “General Purpose Flechette” which releases 80 tungsten flechettes that can penetrate 1.5 inches of roll-hardened armor for use against personnel, some light armour, thin skin vehicles and helicopters.”

Brian


#17

In relation to the Canadian developed CRV7 2.75 inch diameter rocket mentioned above-

U.S. Patent 4770101A, Publication date Sep 13, 1988 http://www.google.com/patents/US4770101
Original Assignee: The Minister Of National Defence Of Her Majesty’s Canadian Government

Multiple flechette warhead

"Abstract
A sub-munition warhead contains several flechettes arranged in a circumferential pattern…The warhead is normally launched with a rocket motor. It is spun so that on burnout, the warhead is travelling at high speed and spinning. On burnout, a fuze is ignited and the piston is propelled down the canister. This drives the flechettes forwardly, rupturing the fairing and allowing the flechettes to separate for independent flight to a target.

BACKGROUND OF THE INVENTION
The present invention relates to sub-munition warheads and more particularly to such a warhead containing a number of heavy kinetic energy penetrators known as “flechettes”.

The warhead of the present invention has been developed for use with unguided air to surface rockets as an area weapon against armoured vehicles. The use of such weapons involves the firing of several rockets, each fitted with a multiple flechette warhead, at a tank formation. On rocket burnout, the individual flechettes separate from each warhead and these aerodynamically stabilized flechettes continue to the target, where they retain enough kinetic energy to penetrate the armour."


#18

Just an aside, but as there is a family connection I thought I’d mention it. My uncle developed the motor for the CRV7 while he worked at DREV (Defense Research Establishment Valcartier). I can remember him talking about an anti-armour warhead, but think that it was more of a single long-rod penetrator type as he was explaining L/D ratios to me (this was ca. 1985).

Here is a motor section of a Bristol Aerospace CRV7:

.

Paul


#19

Very nice! And I believe there was a warhead for it that was a modified TP rocket to AP. Was a nylon/plastic bodies with steel rods inside to simulate weight. They noticed the TP ones where punching holes in target tank hulls so replaced the steel rod with a tungsten one. I believe a member on the BOCN has one.