Bullet proof vests cannot completely guarantee protection against a bullet; some instead refer to them as bullet resistant vests. This is compounded by the fact that there are multiple levels of protection available in bullet proof vests, utilising different materials like Kevlar. It is important to know what types of ammunition a vest is capable of protecting you against. Below is a list of some of the most types of bullet, as well as the weapons they might be used in, and what protection you need for each.
This round is credited as being the most widely used handgun ammunition in the world. The 9mm Parabellum, usually shortened to simply ‘9mm’, is a German made bullet that is commonly used by U.S. Law Enforcement and in semi-automatic pistols. At lower velocities a 9mm will be stopped by a Level IIa vest, but at higher velocities a Level II vest is needed.
The .357 Magnum is a popular round that is credited with beginning the ‘Magnum era’ of handgun ammunition after its introduction in 1934. This bullet is known for its stopping power, and is usually fired from revolvers, although the Desert Eagle is one of few semi-automatics that can fire it. For this ammunition you will need a vest at Level II.
Named for its manufacturer (Swiss ammo makers Sig Sauer), the .357 SIG is almost identical to the .357 Magnum, apart from its reduced recoil. It also boasts increased reliability and is compatible with autoloader platforms. A Level IIa bullet resistant vest is needed against this caliber of ammunition.
The .40 S&W comes from Smith & Wesson and was designed to be used by the Police. It has gained popularity among Officers since its introduction in 1990, and has increased power with decreased recoil compared to similar ammunition. The .40 S&W was originally designed as a shorter version of the 10mm Auto. Protection against the .40 S&W requires Level IIa bullet resistant armor.
The 10mm Auto never gained the popularity that its shorter counterpart (the .40 S&W) did, despite its promise of extra stopping power. This round is designed to be used in semi-automatic pistols, and suffers from high recoil, though has found use in certain branches of Law Enforcement. Stopping the 10mm Auto requires a Level IIa vest.
Famously featured in Dirty Harry, the .44 Magnum is one of the most famous rounds in the world. However, until Dirty Harry it was relatively unknown, despite having been available since 1955. The .44 Magnum is well known for its stopping power, which naturally causes high recoil and muzzle flash. The .44 Magnum requires a Level IIIa bullet proof vest.
The .45 ACP was created for the prototype Colt semi-automatic .45 pistol made by John Browning. From 1911 the US Army has used the .45 ACP, sometimes called the .45 Auto, in its M1911 pistol. It has gained popularity thanks to its high velocity and moderate recoil, coupled with its low muzzle flash, despite it being heavy and costly to produce. Protecting against the .45 ACP requires a vest at Level IIa.
Bullet resistant vests at Level I-IIIa are capable of stopping the vast majority of rounds commonly used in handguns. For protection against high caliber and even armor-piercing rounds however a higher level vest that uses ceramics or polyethylene is needed. Here are examples of the most common high caliber rounds and the armor you need to protect against them:
This round is a very common high caliber round most commonly used in the M16 rifle. Despite being widely used, the 5.56x45mm NATO is affected by the weapon it is used more than any other ammunition is. The 5.56mmx45mm NATO is often criticized for performance issues, but is still popular. A Level III vest will protect against this round.
The .30-06 was primarily used by the US Military from 1906 to 1956, particularly because of its relatively low recoil. For this reason the .30-06 was a very simple cartridge to use. Protecting against a .30-06 bullet needs a Level III vest.
Primarily used by big game hunters and militaries worldwide, the .308 Winchester is one of the most successful rounds in the world. The .308 Winchester duplicates the ballistic performance of the .30-06. A Level III bullet proof vest is needed to protect against this round.
This is another successful rifle round that can be used in a number of weapons. The 7.62mmx51mm NATO is a versatile round that shares similarities with the .308 Winchester and was released in 1954, only 2 years later. The armor-piercing 7.62mmx51mm NATO will need a Level IV vest as protection, though regular 7.62mmx51mm NATO ammunition can be stopped with a Level III vest.
Hard armor is armor that uses rigid plates of ceramic or polyethylene to protect against higher caliber ammunition. Hard armor is available at Level III or IV. For more information on the specifics of the protection afforded by each level, have a look at the NIJ’s official documentation concerning body armor testing.
Written by Joshua Nash for SafeGuard Armor. Josh has written a number of articles as part of SafeGuard. He uses his expert knowledge on ballistics to help inform people in a number of different professions.