Mystery 57mm AP-T

[dmm9623]

Can anyone help in identifying this 57mm AP-T Shell while keeping the following in mind?

Recovered from a remote battlefield on Bataan, Philippines where the U.S. equipped Philippine Army was routed by the Japanese on April 7, 1942.

The Filipinos had no artillery or tank support while the Japanese had full range of artillery and used tanks in the battle.

The design and dimensions closely match to the American M70 AP-T and are within an acceptable margin of error given the heavy corrosion clean-up.

The British 6-Pounder and U.S. M70-AP-T weren’t produced until 1942, well after the Philippines was cut-off from resupply. At the time, the U.S. had no 57mm gun in its arsenal.

The only Japanese 57mm AP Shell I can locate was an AP-HE for use on tank mounted guns.

It's a far reach but perhaps of British or German origin, produced for WW1 or pre-WW2 and sold to Japan under an arms agreement. Either this or I’m missing something from the Japanese reference books.

Any help is appreciated...

 

[ThomasP]

US Army forces (various elements of XI Corps mainly) landed on Luzon in early-1945, and part of their job was retaking Bataan. They brought 57mm AT guns with them, and the guns were sometimes used to suppress/knock out Japanese bunkers during the fighting.

 

[dmm9623]

ThomasP, Thank you for the response. That was my initial feeling as well but I couldn't make sense of it. The Japanese decided not to defend Bataan in 1945 and had only 4000 troops there. About 2700 were at the base of the peninsula and the balance scattered about to the south, the majorioty along the coastlines. Other than the battle at zigzag pass to the north, the U.S. Army fought only two small battles, one at Mariveles and the other at Orion. The only movement inland was along the Pilar-Bagac road where they encountered a few stragglers but no real fighting. Also, the only hardened fortifications were on Corregidor, never any on Bataan. The 57mm shell came from a site about 3km south of the road. It's isolated on a valley floor with high, steep sides. The more I read, I see that the British 6-Pounder and U.S. 57mm AP-T shell were nearly identical and interchangeable. I haven't found any info of the French 6-Pounder shell but assume they would have had an AP-T similar or identical in design. The Japanese adopted the Hotchkiss 6-Pounder soon after it was made available in the 1880s. It could be that the Japanese Army used up their stocks of the 57mm AP-HE in China and other battles so they borrowed from naval stocks that included the AP-T. This assumes that the Army 57mm gun and Navy 6-pounder were chambered for the same round. There are a lot of assumptions made here but with the U.S. Army eliminated as a candidate, nothing else makes sense. Simply put, the French designed and produced the AP-T shell and the British, U.S. and Japanese adopted the same design. Does any of this make sense?