Excerpt from the June 21, 1969 issue of Science News
A new, lighter bulletproof armor ... composed of boron carbide fibers ... [is] capable of stopping a .30-caliber bullet.... The armor weighs about six pounds per square foot, compared to previous boron carbide armor of seven pounds per square foot.... Until now boron carbide armor has been used mainly to protect vital helicopter parts, but the lighter weight means it could be worn by ground troops. — Science News, June 21, 1969
Many boron carbide armor components have been replaced by Kevlar, which was developed around the same time (SN Online: 4/8/15). Made of woven synthetic polymer chains, Kevlar fast became essential wear for soldiers and law enforcement officers. More than eight times the tensile strength of steel, the textile distributes the energy of a bullet impact over a large area. Some modern body armor systems today weigh a tenth of their boron carbide counterparts. Scientists are testing engineered spider silk, another strong and flexible textile, for body armor (SN: 5/11/19, p. 24).
J. Rehm. Bacteria can be coaxed into making the toughest kind of spider silk. Science News. Vol 195, No. 9, May 11, 2019, p. 24.
M. Rosen. Spiders spin stronger threads with nanotubes. Science News. Vol. 187 #12, June 13, 2015, p. 12.
T. Siegfried. Top 10 science anniversaries of 2015. Science News Online, April 8, 2015.