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What Is the Best 5.56 Ammo for an AR Pistol?

An AR pistol is a great option for those who want an AR rifle without the size and distance. The AR pistol is better suited for close-proximity shooting rather than long-distance. If you are looking for the best possible ammo, then we’ve got you covered. 

The best ammo for an AR pistol is Federal XM855 62-grain FMJ ammo. It’s the best overall choice for an AR pistol because it’s penetrative, powerful, and has the right weight to get the job done accurately.

Let’s talk more about this ammo and the best way to select ammo for your AR pistol. 

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What Makes Federal XM855 62 Grain the Best Ammo for an AR Pistol?

Federal XM855 62-grain ammo is the best choice for overall use with your AR pistol because it’s penetrative, effective, and allows for accurate shots from an AR pistol. 

An AR Pistol is an AR-15 rifle with no stock. The AR pistol has a barrel much shorter than the traditional AR-15 rifle, making it slightly less accurate but easier to conceal. With accuracy being a concern for the AR pistol, it’s vital to get ammo that can help your shot be more accurate and effective upon reaching the target.

62-grain ammo is best for twist rate, which I will discuss in more detail later. But it also allows for a more effective and penetrative shot, which will ensure you do as much damage as possible with a single bullet. 

Rather than simply strike and fragment, this ammo will penetrate targets. So, it’s often not welcome at traditional shooting ranges because of the damage it can do to walls and other surfaces. But that’s what makes it the best overall ammo to use with your AR pistol. 

If you’re using your pistol, you’ll probably need to do some damage. So, this ammo will help you do just that. But, make sure you get used to it before using it in situations that include walls or objects you want unbroken nearby.

An AR 15 Pistol With Rounds

Is Federal XM855 62 Grain Ammo Best for Self-Defense?

Federal XM 855 62-grain ammo is best for self-defense with an AR pistol because it’s quick, effective, and will penetrate targets. The penetrative characteristic of the ammo can be a downside if you live in an apartment. 

Safety should always be the first priority when choosing ammo for self-defense. Federal XM855 will help keep you safe by piercing through most objects. It’s especially useful when it has to pass through something else to get to the target. 

The power behind this ammo allows it to travel through walls, glass, and even armor. This means that your assailant doesn’t even need to enter the room before you can start defending yourself. It also means that anything the person is wearing won’t hinder these bullets. So, it allows you to protect yourself and your family from any situation. 

Whether you hit the target right on or pass through something first, Federal XM855 can keep you safe from a good distance away from the target if necessary. 

As mentioned, you should ensure accuracy when shooting this type of ammo. That’s especially true for those who share walls with other homes like an apartment or townhouse setup. A misfire with this ammo can penetrate many different things, like glass and drywall. So, you may be putting your neighbor at risk with a careless shot. 

Focus on careful and precise shooting before considering this ammo and gun combination. Then, once you have mastered shooting precisely, it will keep you safer than most other types of ammo. The penetrative and powerful nature of this ammo allows you to do the most possible damage with just one shot. 

Related What Is the Most Accurate Manufactured 5.56 Ammo Brand?

M855 ammo, or green tip ammo as some call it, is legal to own in the US. Though some laws vary from state to state, there are currently no federal laws forbidding ownership of this ammo. 

Green tip ammo has been a target of attempted regulations for years now. So, many people wonder whether it’s legal to own. Let’s break down some of the rules about owning M855 ammo and why it has been controversial. 

The military originally used M855 ammo as it promised to penetrate armor and other surfaces. So, the ATF considered this ammo to be dangerous in the hands of civilians who may come face to face with law enforcement. 

The idea was that armor-piercing ammo put police in danger and threatened the Law Enforcement Officers Protection Act of 1985. And they originally made this ammo to rip through armor, walls, and nearly anything else that stood in the way.

However, M855 only has an 80% lead core. This means that it doesn’t fulfill the definition of armor-piercing ammo, making it legal to own. So, check with your local state regulations, but federally, you’re in the clear to own this type of ammo. 

As far as the future of M855 ammo is concerned, it’s hard to tell what may happen next. However, it’s comforting to know that the ATF hasn’t made a serious attempt to ban the ammo since it failed in 2015. So, it’s pretty safe to say your M855 ammo is safe to own and use for years to come. 

What Is The Difference Between XM855 and M855 Ammo? 

The only difference between XM855 ammo and M855 ammo is that the M855 is for military use while the XM855 is sold to civilians. Whether the X is there or not does not change anything about the ammo, just who it is sold to. 

It can be confusing to see XM855 and M855 ammo, as they may seem like different things. When it comes to the composition of the ammo, there is no difference between the two. M855 ammo is the exact same as XM855 ammo. The only difference is the name. 

The reason that these two types of ammo are named differently is because they have two different destinations. The M is M855 and XM855 stands for military. This means that this type of ammo was created for use by the military. The X in MX855 ammo is there to let manufacturers know it is set aside for civilian use

So, contrary to what some may believe, the XM855 is not a second-rate version of M855. Rather it is the same exact ammo that is marked to be sold to civilians rather than the military. So, there is no difference in specifications or materials used to create these two ammo types. 

What Grain 5.56 Is Best?

Box of Federal 556 XM855 Ammo

The best 5.56 grain is 62-grain ammo because it allows the bullet to twist faster than lighter ammo. As the bullet twists more in the barrel, it becomes more stable and less likely to tumble or be inaccurate

An AR pistol has a shorter barrel than a traditional AR-15, meaning that there’s less time for the bullet to twist when fired. The typical AR pistol barrel length is either 7 or 10.5 inches (17.78 or 26.67 cm). This means that you would need ammo with a 1:7 and 1:10 twist rate, respectively, to get a full twist out of ammo fired from the AR pistol. 

If your AR pistol has a 7-inch barrel, then you would want ammo with a 1:7 (or as close as possible) twist rate to ensure it’s effective. 62-grain ammo has a 1:8 or 1:7 twist ratio, making it the right fit for this length of the barrel. We’ll talk more about the importance of twist rate when it comes to firing ammo in the next section. 

Besides the twist rate of the bullet, there are other factors to consider for a heavier bullet. The ability to keep their course and withstand any outside influences makes heavier bullets like 62-grain ammo better. When shooting, especially longer ranges, the wind will be a huge factor. A heavier bullet can withstand more wind to remain more accurate than a lighter bullet. 

Heavier grain bullets will also provide better penetration when reaching the target. 62-grain ammo is a lot more likely to travel through a target than 55 grain. Though they may not sound that different in weight, you’ll see a significant difference when comparing the two. 62-grain ammo will provide you with better penetration. 

One of the downsides of heavier ammo is that it may not travel as far as lighter ammo. You’ll get more distance from 55-grain ammo than 62-grain ammo fired from the same gun simply because 55-grain bullets are lighter and easier to move. 

Another downside of heavier ammo is that it creates a stronger recoil when fired. It’s common for heavier bullets to create more recoil because it takes more power to fire them, but it will vary based on the gun itself. It’s often a small price to pay for using a heavier bullet and can be accounted for when shooting.

Why Is Twist Rate So Important for Shooting?

Twist rate is vital for shooting because having the proper spin on a bullet helps it be more accurate and travel further. If you want your shot to be stable, you should factor the twist rate into gun and bullet choice. 

Twist rate is so important specifically for the AR pistol because it has a short barrel length. A shorter barrel length means that the bullet has less time to twist inside the barrel. Twist rate changes per bullet weight and type. So, a bullet with a 1:7 twist ratio needs at least a 7-inch (17.78 cm) barrel to complete a full twist before it leaves the barrel. 

So, let’s talk about what a twist rate actually does for a bullet when it’s fired. One full rotation should be the main goal of a twist rate when firing a bullet. It will allow the bullet to spin at an appropriate speed to keep it stable when fired. 

Bullets need to spin to maintain stability as they move through the air. Otherwise, air, wind, and many other factors would make the bullet wobble as it flew through the air. Spin allows the bullet to travel straight, piercing through the air and other obstacles along the way. 

So, it’s best to ensure that your ammo has the appropriate twist rate to match the size of the barrel you are shooting from. An AR pistol should use a 1:7 twist rate bullet at least to achieve a straight and accurate shot. 

Is 62 Grain or 55 Grain Better?

5.56 Ammo on White Background

62 grain is better for an AR pistol because it has a lower twist rate and will allow the bullet to travel straighter when fired. 5.56mm ammo is affected by a shorter barrel length. So, you’ll need to do everything possible to ensure that your bullet reaches the target effectively. 

While both 55 grain and 62-grain ammo work in longer barrels, it’s important to note that 62 grain will have a better twist rate. So, it will be more accurate when fired from an AR pistol. 

But let’s break down some other differences between the two ammo weights and see why 62 is the winner. Heavier ammo tends to penetrate better than lighter ammo, especially at short distances. So, 62-grain ammo will give you a lot more penetrative power behind your shot than a 55-grain bullet. 

On the other hand, 55-grain bullets will fragment more than 62-grain bullets upon hitting the target. So, the choice depends on what you’re looking for. 62-grain ammo is more likely to put a straight hole through the target. In fact, it’s more likely to put a hole through your wall or door if needed. 

So, if you’re looking for pure strength from your ammo, then 62 grain is the best way to go. Its twist rate will only help you with accuracy when firing from an AR pistol and allow the bullet to travel further. 

Parting Shot

Over the Federal XM855, 62-grain ammo is the way to go for doing the most damage with your AR pistol. It will help with accuracy because of its twist rate, and its power is undeniable. Whether you’re defending yourself or just enjoying the hobby, this ammo will not disappoint.

For more, check out How Much Does Ammo Cost? | Detailed Price Analysis.