Protection against a bullet can never be fully guaranteed, but a bullet proof vest- sometimes instead referred to as a bullet resistant vest- can help protect you and will certainly be more useful than nothing. It is important however to be aware that there are different levels of protection available in body armor, and that certain vests will only protect against certain types of ammunition. Here is a list of the most common types of bullets, the weapons they can be used in, and the protection you will need to protect against each:

9mm Parabellum

The 9mm Parabellum is often shortened to simply '9mm', and is credited as being the most widely used handgun ammunition in the world. The 9mm is a German made bullet commonly used by U.S. Police Officer in semi-automatic pistols. At higher velocities a Level II vest is needed, but at lower velocities a 9mm will be stopped by a Level IIa vest.

.357 Magnum

This round is credited with beginning the 'Magnum era' of handgun ammunition after its introduction in 1934, and has found popularity worldwide. This bullet is usually fired from revolvers and is known for its stopping power. The Desert Eagle is one of few semi-automatics that can fire it. A vest at Level II will protect against this ammunition.

.357 SIG

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.

.40 S&W

The .40 S&W was manufactured by Smith & Wesson and designed to be used by Law Enforcement. It gained popularity among Officers after its introduction in 1990, and boasts superior power and better recoil over similar ammunition. The .40 S&W was designed originally as a shorter version of the 10mm Auto. Protecting against the .40 S&W will require a Level IIa bullet resistant vest.

10mm Auto

The 10mm Auto, often called the 10mm, was never as popular as its shorter counterpart (the .40 S&W), despite boasting extra stopping power. The 10mm was designed to be used in semi-automatic pistols, yet suffers from high recoil. This has not stopped it from finding use
in certain branches of Law Enforcement however. To stop the 10mm Auto you will need a Level IIa vest.

.44 Magnum

Famously featured in the film Dirty Harry, the .44 Magnum is one of the most famous rounds in the world. However, it remained relatively unknown until it was featured in the film, despite having been first manufactured some 20 years previously in 1955. The .44 Magnum is famous for its stopping power, which naturally causes muzzle flash and high recoil. The .44 Magnum will need a Level IIIa bullet proof vest.

.45 ACP

The .45 ACP, sometimes called the .45 Auto, was created for the prototype Colt semi-automatic .45 pistol developed by John Browning. The US Army has used the .45 ACP in its M1911 pistol since 1911, and it has gained popularity because of its moderate recoil and high velocity. The .45 ACP has a low muzzle flash, but is heavy and costly to produce. Protecting against this round requires a vest at Level IIa.

Stopping the majority of handgun rounds is possible with bullet resistant vests at Level I-IIIa. Protection against high caliber and even armor-piercing rounds will instead need a higher level vest that uses ceramics or polyethylene. Here are some examples of common high caliber rounds and the armor you will need to protect against them:

5.56x45mm NATO

The 5.56mmx45mm NATO is a very common high caliber round most used in the M16 rifle. Despite its popularity, the 5.56 suffers from performance issues and has often been criticized for this. It is affected by the weapon it is used in more than any other ammunition. 5.56 is often criticized for performance issues, but is still popular. A Level III vest will protect against this round.


The .30-06 was used by the US Military primarily from 1906 to 1956 due in part to its ballistics properties. The .30-06 round requires a Level III vest.

.308 Winchester

The .308 Winchester is used primarily by big game hunters and militaries worldwide, making it one of the most successful rounds in the world. The .308 Winchester duplicates the ballistic performance of the .30-06, and needs a Level III bullet proof vest to protect against it.

7.62mmx51mm NATO

This is a very successful rifle round that can be used in a number of weapons, making it a very versatile option. The 7.62mmx51mm NATO 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.

Armor that can protect against high caliber ammunition is known as 'hard armor', and uses rigid plates of ceramic or polyethylene. 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.

*Note: Body armor may not be legal in all areas for civilian use, check your local laws before purchasing or wearing body armor. Also, federal law prohibits possession of body armor by felons. The more you know...Editors.

Author Bio: Written by Joshua Nash for Josh has written a number of articles on behalf of SafeGuard Clothing about body armor and ballistics. He uses his expertise on ballistics and trends in body armor to help inform people in a wide variety of professions.