Type IV Bulletproof Armor (5e Equipment)
From D&D Wiki
Type IV Bulletproof Armor
Most bulletproof armor is made from ballistic paneling that chips away on impact, redirecting the force of a gunshot. Type IV is designed for protection against military grade rifles loaded with armor-piercing ammunition. This is the armor of choice for frontline soldiers expecting combat. Most militaries will outfit their soldiers with this level of armor, if they get the chance.
Usage notes are unresearched speculation designed to give perspective only. The DOJ standard is only used to distinguish between different levels of armor, and applies generalizations so it can be adapted for D&D. Please, don't take this stuff literally.