How effective was the M1 helmet in the US WW2 against bullets and explosive fragments? Did regulation require the helmet to be worn at all time or was it a personal decision? -
![A combination of four pictures show German Bundeswehr army soldiers with the Delta platoon of the second paratroop company 373, wearing helmets with nicknames, during a mission in the city of Iman A combination of four pictures show German Bundeswehr army soldiers with the Delta platoon of the second paratroop company 373, wearing helmets with nicknames, during a mission in the city of Iman](https://c8.alamy.com/zooms/6/c726cb05dac94410b977a0b36de40f1b/2e5mdna.jpg)
A combination of four pictures show German Bundeswehr army soldiers with the Delta platoon of the second paratroop company 373, wearing helmets with nicknames, during a mission in the city of Iman
![Original U.S. WWII Vietnam Reissue M1 McCord Front Seam Swivel Bale He – International Military Antiques Original U.S. WWII Vietnam Reissue M1 McCord Front Seam Swivel Bale He – International Military Antiques](https://cdn.shopify.com/s/files/1/1524/1342/products/ONSV10012__07.jpg?v=1621529782)
Original U.S. WWII Vietnam Reissue M1 McCord Front Seam Swivel Bale He – International Military Antiques
![Very cool post Vietnam early Kevlar helmet with writing - M-1; M-1C & M-2 HELMETS - U.S. Militaria Forum Very cool post Vietnam early Kevlar helmet with writing - M-1; M-1C & M-2 HELMETS - U.S. Militaria Forum](https://www.usmilitariaforum.com/forums/uploads/monthly_09_2016/post-163344-0-19496400-1474742236.jpeg)