Sorry that is what we got in the field in Safety of Use Messages (SOUM's), as well as coming from Fort McCellen Army Safety Board. It was not the Army that did had the incident, it was another service. It is what was reported to the field units in multiple documents, the SOUM also had us make sure we using standard Army Ball ammo. Allegedly and this was some 30 plus years ago, it was ammo for an Uzi. I can't confirm that part of it, but can say with certainty back in the 1980's when it occurred that was we got. We also had to go back and check all of our M9's to see if their were any issues. When I went to Aberdeen for the Automotive WO course, they cover small arms, and it was brought there as well, and that was in the early 2000's.
A quick search and here is the link to the GAO testimony on the M9 issue:
Little is known about the actual number of rounds
fired, because there was no requirement to keep a record of the
rounds fired or the type of ammunition that was used. Navy
officials estimated that the first failure occurred after about
30,000 rounds and the second after about 4,500 rounds. It is
believed that the first weapon was firing non-NATO standard
ammunition. While the contract requires that the M9 be designed to
fire NATO standard ammunition, the contract warranty is not
breached by firing other than NATO standard ammunition.
Ref:
https://www.gao.gov/assets/110/102286.pdf Page 10 of the Report on Quality and Safety Problems with the Beretta M9 Handgun.
Another reference to slide failure on high count M9's from the 2008-2009 time framed, not an official reference:
https://www.ar15.com/forums/handguns/M9_Safety_Message/15-76807/