The ping noise is accurate. It is the strip clip popping out. My grandfather told me how they would carry used strip clips and occassionally use their fingers to "pop" them to make the noise. They did this to fool German soldiers into thinking they were out of ammo.
Mostly accurate. The en-bloc clip (s'not stripper clip, that's something different) on the M1 holds 8 .30-06 cartridges together and is fed "en-bloc" into the rifle magazine. It is held in place by a latch that, when the last round is fired from the weapon and the bolt locks back, is released by the magazine follower and is propelled out of the rifle by the follower spring. That lovely ping noise is made only when the weapon is empty and the en-bloc clip is ejected. Josh said they were limited by the engine mechanics and it was not worth reworking the reload mechanics for just one weapon so the "ping" occurs when the last round is fired. Instead they tagged it to the reload function. It occurs at the beginning of the reload fuction, and if you fire all the rounds from the rifle and allow the game to auto-reload the weapon for you, it occurs at the correct time. But it also will occur any time you hit the reload button, which is not how the weapon works in real life. You can't easily top off an enbloc clip while it is in the weapon. The magazine follower is the device that holds the bolt back and you would have to manually hold the bolt back while you try to feed rounds into the en-bloc clip sitting inside the magazein well. You
can remove loaded en-bloc cilps from the rifle by means of the clip latch, and insert a fully loaded clip in it's place, saving the partially used en-bloc clip to top off at a later time. The part about using empty clips to reproduce the sound of an empty rifle is, AFAIK, accurate. My father mainly lugged the BAR around, but I believe he mentioned it at some point.
PS (a stock military M1 is a helluva lot more accurate than protrayed in the game. Of all the surplus weapons I've fired over the years, a surplus CMP M1 was probably the most accurate.)
-Gunny out.