What is Green Tip Ammo? 5.56 vs. SS109 vs. M855 vs. XM855 vs. .223 Bullets

Have you recently purchased your very first AR platform rifle? Have you been shooting with different rifles for quite some time? You might have heard of “green tip ammo” before. We refer to it as the penetrator round or 5.56 cartridge because of its steel core, 62-grain projectile, and ability to swift through dense targets. The United States military officially calls the 5.56 cartridge the M855. The letter “M” stands for munition, in case you do not know what it means.


What is green tip ammo?

The green-tip ammunition, also commonly referred to as the .223/5.56 Rem caliber, was intended for use with the AR platform. These rounds were involved in several controversies because of their supposed armor-piercing features, as defined under the federal law of the United States. 

During its inception in the 1970s, we refer to the green-tipped ammo as the SS109. The Belgians invented the SS109 round, which they won in a NATO standardization trial. At that time, no official standardizations were available for the 5.56 round. As part of the requirements, NATO wanted a cartridge that offers excellent penetrating ability at an extended distance. Shooting the rounds at steel helmets was a part of the trial process.

In the early 1980s, the United States military adopted the SS109 as a replacement for the M193 5.56 ammo. This time they renamed it the M855 and painted the tip color green. So what was the significance of going the extra mile of painting the tips? So troops can easily distinguish between the old M193 rounds and the new M855. The US military gradually phased out the M193 after replacing it with the M855, but the tradition of painting the tips green remains.

Firearms and ammunition manufacturers in the United States introduced the M855 to the commercial market. Some manufacturers market the M855 under a different name. For example, Federal sells the M855 under the name XM855, with the letter X indicating it is for civilian sale. Other manufacturers, such as Winchester, kept using the same name.

farmer carrying a rifle

What characteristics make the M855 armor piercing?

As mentioned in the previous section, the green-tip ammo had involvement in several controversies, one of which was armor piercing.

The classification of armor-piercing ammo falls under two categories – bullet core content or jacket concentration. Bullets need a heavier weight to puncture through armor. Such types include depleted uranium, brass, iron, steel, tungsten alloy, bronze, or beryllium copper.

Lead makes up most non-armor piercing bullets. It is far lighter than the other types mentioned earlier. The jacket concentration is another way of doing it. A jacket weight exceeding 25% of a .22 caliber projectile’s total weight is considered armor-piercing. 

Why is it not classified as armor piercing?

body armor

The M855 does not fall in any of the two categories outlined in the previous section. Lead still makes up for the core content, similar to other conventional bullets. Moreover, the jacket’s weight is not more than 25%. Although the tip is steel, the ATF did not mention it in its guidelines.

More testing in the M855 during combat proved its effectiveness at long ranges. In certain instances, it could not penetrate a vehicle’s windshield even when fired at a closer range. 

Can civilians legally purchase green-tip ammo?

women practicing shooting

As of this writing, US civilians in the United States can legally acquire it under federal law. However, some states have their own applicable rules when owning ammunition. For example, California has the Draconian gun laws, limiting what state residents can have at a given time. For best practice, we recommend checking the local laws of the state you reside in before purchasing. It should save you the trouble.

In the past years, the federal government and the ATF have made numerous attempts to ban the M855. The most recent effort followed the 2015 regulations that forbade the use of lead ammunition on federal property. Since then, these environmental limitations have lifted. The ATF also raised that it is armor-piercing and should not have a sporting exemption. However, it contains 80% lead and does not meet the definitions of an AP.

Pros and cons of green tip ammo

The green tip ammo is a bit slow and heavy compared to other similar ammo, such as the 55 grain M193. It also has superior penetration over the 62 grain M193, making it a better option for most consumers. The heavier weight makes it slower, but the longer length makes for a better ballistic coefficient. Below is a quick summary of its pros and cons.

shooting practice


  • It has more resistance to environmental factors, such as wind and dust.
  • The green tip makes it more noticeable.
  • Better overall penetration.
  • Better resistance towards fragmentation.


  • It is more expensive.
  • The damage it costs is not devastating.
  • It will destroy steel targets.

What is 5.56?

The 5.56 was developed in the 1970s by FN Herstal in Belgium. It has a rimless bottleneck intermediate cartridge. The STANAG 4172 standardized it as the second standard service rifle cartridge for some non-NATO countries and all NATO forces.

Brief History

The first standard NATO rifle cartridge, the larger 7.62 NATO, was selected in 1954. It encountered a few criticisms during the selection process. To note, the 7.62 NATO did not meet the minimum automatic rate of fire for modern combat.

The British were about to adopt the .280 cartridge when the NATO standard of 7.62 was decided. It had significant evidence from their research with intermediate cartridges since 1945. The FN firm had also contributed to the .280 round’s development by creating a .280-capable version of the FN FAL. The US overruled the concerns about the 7.62’s overall effectiveness and recoil, and the other NATO countries agreed that standardization was more important.

In the 1950s, ArmaLite and other firearms manufacturers in the United States developed their small caliber high velocity (SCHV) rifles using the commercially available .222 Remington cartridge. ArmaLite reached out to Remington to design a similar cartridge with a shorter neck and longer case body. It was after it was made clear that there was not enough powder capacity to meet the penetration and velocity requirements set forth by the United States Continental Army Command (CONARC). .222 Remington Special was the name assigned to this new design. It was renamed to .223 Remington later on to prevent confusion.

The United States military adopted the ArmaLite M16 rifle in 1963. It paved the way for the standardization of the .223 Remington as the 5.56 NATO.

Cartridge Dimensions and Barrel Configurations

The case capacity of the 5.56 is 1.85 ml. Its dimensions are 5.56 mm x 45mm. NATO picked a rifle twisting rate of 178 mm.

What is m855?

One of the most popular rifles in the US is the AR-15. It is accurate, easy to use, lightweight, and can run as a pistol, carbine, or rifle. Its modular design makes it possible to run in different modes. The AR-15 can also shoot a selection of 5.56m ammo, ranging from 40 to 77-grain variants. However, a bulk of users prefer the 62 grain for the M855.

Green tip ammo is the more popular reference to the M855 because of its green tip. It is a special color, making it a standout among the rest.

These cartridges pack a 62-grain bullet containing a lead core. The steel tip acts as a penetrator, enabling it to tear through targets easily. The M855 has a muzzle velocity of approximately 3,020 ft/sec. It is a varying value, depending on the manufacturer.

A unique chemical seals the primer and case mouth, similar to the M193. It contains 80% lead and a 7-grain steel tip, making the M855 heavier and slightly slower than similar bullets. However, its longer length results in a higher ballistic coefficient. As a result, the ammo travels on a flatter trajectory.

Many consumers think the green tip ammo has armor-piercing characteristics, but it does not. The steel tip helps it penetrate through barriers, such as thick clothing, glass, and thin gauge metal. Materials, such as modern body armor, brick, and auto glass, are difficult to puncture. Some infantry units reported the ammo had difficulty penetrating windshields, even at a short distance. There are also instances where it could easily penetrate an auto windshield without any problems. It is on a case-to-case basis.

The green tip ammo performs well on barriers. It is an excellent pick when shooting a rifle with a fast twist rate.

Price of 5.56 Ammo

Location, quality, and make are some things that affect the price. Generally, the price ranges between 46 cents to 50 cents per round for Federal and 57 cents to 62 cents for Winchester. Some retailers may price their items more, charging between 74 cents to USD 1 per round.

When looking to purchase, we suggest checking with the nearest ammunition store for the updated price. You can also check for prices online. 

5.56 vs. .223

The differences between these two are minor but impact function, safety, and performance.

Pressure Level

The 5.56 NATO has a higher pressure level than the .223 Remmington. The former runs at 58,000 psi, while the latter runs at 55,000 psi.

Chamber Dimensions

The 5.56 NATO chamber has a throat measurement of 0.125 inches. As an effect, it can accommodate an additional grain of powder loaded into the cartridge, resulting in better performance over the .223 Remington.

Common Issues

We should refrain from firing a 5.56 NATO cartridge into a rifle whose chamber design is constructed for the .223 Remington. The NATO’s longer chamber will cause the .223 Rem to run at 65,000 psi or more, which is about 10,000 psi more than its normal pressure of 55,000 psi. It is not safe and will cause harm to the rifle, operator, or both.

We should also refrain from firing a .223 Rem into a rifle whose chamber design is for the 5.56 NATO. The throat differences could cause not-so-optimal results because of a lack of pressure. It would be impossible to attain the 55,000 psi for the .223 Rem, hurting performance and velocity. There will be more problems if it fires out from a shorter barrel. The 223 round’s lower powder charge and the pressure drop it experiences when fired in a 5.56 NATO chamber will prevent the rifle from cycling properly. Rifles with NATO chambers and barrels longer than 14.5 inches should be able to fire .223 Rem ammo without any issues.

ss109 vs. m855

There are no differences between these two because they refer to the same thing. The United States Military refers to it as the M855, while the NATO refers to it as the ss109. 

Belgium is the origin of the ss109 designation, where you can find FN Herstal. The ss109 cartridge was developed by FN Herstal before the US Military’s adoption a few years after. 

Green Tip m855 vs. m193

The M855 and M193 are some of the most common rounds for weapons with a 5.56x45mm NATO chamber. Below we will outline some of their differences.

The M193 5.56 cartridge was developed in the early 1960s and had its first appearance in Vietnam. It was the primary round for the M16 guns until the 1980s when NATO standardized the M855. The full copper jacket and lead core of the M193 exhibit a boat tail projectile. It weighs about 55 grains and travels at 3,165 ft/sec from the muzzle.

The M193 causes fragments inside soft tissues when hitting through a flesh target. However, if it does not fragment, it may produce very minimal wounds.

On the other hand, the M855 pushes a 62-grain boat tail projectile, steel penetrator tip, and a lead core. The M855 travels at 3,020 ft/sec from the muzzle, with the case mouth and primer chemically sealed. The M855 differs from the M193 because of its improved penetration design. As such, the M855 has become the standard ammunition of the US and other NATO member countries since 1982. 

The M855 is not armor-piercing but can be effective when punching through barriers. It penetrates thick clothing, brush, glass, and thin metals quite well. However, it does a poor job plowing through body armor, brick, and auto glass.

If you are choosing between these two, we recommend picking the M855 if you want to shoot with a rifle with a fast twist rate of 1:7 or 1:8 or poke holes through a hard barrier. On the other hand, we recommend picking the M193 if you want to shoot with a rifle at a slower twist rate of 1:9, 1:10, or 1:12. The M193 is also more effective at soft targets.


Is green tip ammo illegal?

Under federal law in the United States, the green tip ammo is not illegal. However, some states have certain restrictions or rules revolving around it. Before purchasing, we recommend you check your state laws to avoid any issues. 

Is a 5.56 green tip better?

It is not always better. These are on a case-to-case basis. The 5.56 green tip is effective for penetrating glass, thick clothing, glass, and thin metals.

Is green tip 5.56 good for home defense?

Yes, it is a decent pick for home defense. Its price is reasonable too. It can easily take out rats, too.