I was talking with a Viet Nam vet who chiefed a M109 on one of the firebases over there. One night there was a determined effort by the VC to overrun the place and they went into direct fire with beehive. After everything was over, FDC (Fire Direction Center for those who don't know) called down the line asking how many beehives each gun had expended. When this chief answered up, he told them zero. They then asked why he'd shot all the 30 rounds in his ammo load and he told them that with everything going on, that was all he'd had and he couldn't get any of the other crews to give up any of theirs.
I did get in Firebase Bearcat right after the VC tried to overrun it and the Korean gun crews went gun deck level with Beehive. There base engineers were out with bulldozers shoving the bodies into trenches the day I got there.