Just some things I have noticed and thought were interesting.
On 31 October 1968 1st Battalion, 40th Artillery, 108th Artillery Group wrote in their Quarterly Operations Report-Lessons Learned:
"(1) Body Armor, Fragmentation. Protective, with 3/4th collar FSN 8470-823-7371
(a) OBSERVATION. US Army Body Armor FSN 8470-823-7371 appears to be less durable and to provide less protection than the USMC body armor FSN 8470-576-4193.
( EVALUATION. Under normal wearing conditions in this battalion the US Army body armor begins to deteriorate in approximately four months. The seams of the exterior covering tear and the inner protective webbing begins to roll and mat. The US Army body armor clings to the body preventing adequate air circulation around the upper body, thus greatly contributing to heat casualties. The USMC body armor, worn by many of the men in this battalion, does not have nay of these faults. It is also believed that the fragment stopping power of the USMC body armor is greater. An EIR concerning the durability faults of the US army body armor was submitted by this organization on 30 April 1968.
© RECOMMENDATION. That armor, body armor fragmentation protective, FSN 8470-823-7371 (US Army) be reevaluated and compared with armor, fragmentation protective FSN 8470-576-4193 (USMC) for durability and fragment protection and that the better armor be adopted for use by both services."
HEADQUARTERS, UNITED STATES ARMY, VIETNAM responded:
"2. Comments follow: a. Reference item. concerning body armor, fragmentation, protective, with 3/4 collar FSN 8470-823-7371, page 6, paragraph 2b(l): nonconcur. The unit submitted an EIR on the Army's body armor which will result in a reevaluation of the vest. Through an interservice supply stockage agreement, USMC body armor could be requisitioned by the Army. Meanwhile, a new variable type body armor is undergoing evaluation by selected USARV units. The new vest was developed by Natick Laboratories and is designed to provide protection against fragmentation and small arms fire with the addition of ballistic plates in chest and back pockets."
Some soldiers of 1st Battalion 6th Infantry, 198th Infantry Brigade (Light), 23rd Infantry Division wore M1955 Flak Jackets
101st Airborne, Camp Eagle 1970.
If you have any info on the Army wearing M1955 or other USMC vests please share.