The short answer is “it depends.” The question itself requires a bit of nuance, as there are several things that qualify as a “bulletproof vest” and not all of them are rated to stop an AK-47. The question shouldn’t even be “can a bullet proof vest stop an AK-47.” Rather, it should be “what kind of vest can stop a 7.62x39?”
Currently, there are several firearms which use the AK-47’s 7.62x39mm round. While the most famous of these is the AK-47 itself, this Soviet round is also found in certain variants of the CZ 805 BREN, IWI Galil ACE, SKS, Robinson Armament XCR, and even AR platform rifles. If a particular vest can stop a round from a Galil, it’ll stop a round from an AK-47 just as well.
The appended “x39” to the AK-47’s ammo designation is important to distinguish it from the 7.62x51mm NATO and the 7.62x54mm Russian rounds. Some sites erroneously state that the AK-47 shoots full-sized rifle cartridges like the 7.62x51mm NATO when in fact, the Soviet rifle uses 7.62x39mm Soviet ammo.
When it comes to the issue of protection, not every type of body armor is guaranteed to stop the 7.62x39. For example, the Level IIA and IIIA soft armor vests typically used by personal protection officers and police are normally only rated for pistol rounds, vulnerable to anything larger than a .44 magnum.
For example, in 2022, a Las Vegas metropolitan police officer was killed while investigating a domestic violence incident. The suspect was using an AK pistol chambered in 7.62x39mm, which defeated his body armor and tragically ended his life.
In the same way, the US military’s flak jacket – a Vietnam era relic that might pass as modern body armor in the developing world – was never meant to protect soldiers against direct enemy fire. This 10-pound vest, twice as heavy as a modern IIIA vest, could not even stop large caliber pistol rounds which modern soft armor can do with ease. Accurate fire from even a poorly maintained SKS would kill a Vietnam-era soldier in full kit.
An extremely unsafe test of a bulletproof plate against an AK-47.
Only Level III and Level IV plates can stop rifle rounds of any kind. These plates are made of rigid materials like steel or ceramic materials blended with aramid fibers and bonded with resin. The resulting material is a hard but lightweight plate capable of defeating intermediate rifle rounds at Level III such as the 5.56x45mm, 7.62x39, and 7.62x51mm NATO, while Level IV plates are rated for larger caliber rounds such as the .30-06 AP, also known in the military as the M80.
No longer issued flak vests, modern US military personnel are equipped with IBA and IOTV armor. These modern protective vests are built to be used together with Level III and Level IV plates, meaning they are resistant to most enemy small arms calibers .30-06 and below.
Sergeant Joseph Morrissey, who deployed with the 82nd Airborne to Afghanistan in 2012, was on the receiving end of a five-round burst of AK-47 fire delivered from only 30 yards away. He was back on patron in just 48 hours, since his IBA was outfitted with life-saving plates of rigid armor.