1. The M1 Garand Rifle used a "clip" which held 8 bullets. Afterfiring all 8 rounds, the clip would eject from the rifle. The 4 bullets on the helmet would be useless.
2. The Sergeant us using a Thompson Sub-Machine gun.The bullets on his helmet won't work in his gun,
2. Contrary to this movie, there were no Black men in the 101st Airborne in WWII. There were no integrated combat units in WWII.