There are people in Europe who are expert at finding battle sites. One of these groups found the site outside of Holtzwihr, France where Audie Murphy won his Congressional Medal of Honor. One of the group sent a letter to a collector friend of mine along with 2 spent .50 caliber cartridges. My collector friend sent me copies of the letter that was originally written along with a personal note concerning the find and he included one of the cartridge cases. I have removed the parts of the letter which have no bearing on the cartridge. In the letter he also mentions visiting the Cleurie Quarry where Audie won his first Silver Star.
Of course, there is no way to prove that Audie actually fired this cartridge but there is a reasonable chance that he did. According to the Simpson book, the machine gun on the M-10 that Audie mounted had been fired by the crew at the advancing troops before the M-10 was hit. At least, I think this round likely came from the same machine gun that Audie used because of the proximity of the M-10 parts. Those parts would have likely come from the M-10 that blew up and that's the one Audie had been on. The other M-10 had slid into a ditch at such an angle that the guns were of no use.
This visit to the site was in 1992. There was a subsequent visit to the site that is described on the Audie L. Murphy Memorial Website.