15 Nov
Articles

Is it Better to Build or Buy an AR-15?

Should I purchase or construct an AR-15? If you visit any AR-related internet forums or Facebook groups, you will inevitably run into people who are debating whether to purchase a ready-made firearm or construct one themselves. This debate has been going on for years because of the abundance of parts and the simplicity of using the AR platform.

What are the benefits and drawbacks of building a rifle as opposed to purchasing one from a manufacturer? If you put one together yourself, can you save money? This first part of a two-part post should hopefully help dispel some misinformation and emphasize the solutions that many people are seeking.

We’ll start by examining purchasing an AR-15 from a producer or a store in order to decide if you should build one or buy one. When purchasing directly, all assembly, parts, troubleshooting, and other tasks should be completed before the handgun is sent to you. A pre-built gun will be guaranteed by a manufacturer’s warranty and constructed in accordance with industry standards before you even touch it.

The main advantages of purchasing something that has already been put together will vary depending on the brand you choose, and will include these warranties, quality control procedures, and overall gun quality. Finally, this will provide you with a product that is ready to use right out of the box and will only need a small financial commitment.

So what are the drawbacks? The sector is currently seeing its highest level of demand in quite some time, thus there may not be enough supply. Additionally, quality control has suffered universally as a result of trying to keep up with the demand (though any company worth supporting will still handle any issues without hesitation). Unless you want to spend additional money on parts and change them out on your own or have someone else change them for you, purchasing something also ties you into the configuration that the manufacturer picked.

Depending on the business you choose to purchase from, there is one more significant possible negative.

Companies that have staff who are well-trained, adhere to strict quality control procedures, and care about the items they produce will produce goods that are of high quality.

There are businesses that make an effort to concentrate on producing high-quality firearms that are constructed in accordance with the necessary requirements and put through rigorous quality control procedures in order to work with a high degree of dependability. Bravo Company, Sons of Liberty Gunworks, Sionics, and much larger firms like Knight’s Armament, and FN are excellent examples of companies that adhere to this philosophy. All of the individuals mentioned will take the necessary steps to port barrels correctly, use parts made of the appropriate materials, concentrate on individual inspection of items rather than batch testing, and more.

Due to the amount of attention and consideration given to them at each stage of the production and assembly process, these firms have components and firearms that, in comparison to some of the competition, are frequently as different as night and day. With the exception of Knight’s Armament, who employ a different class of threading, the staking (or lack thereof) on a factory gun’s castle nut is a pretty great indicator of the amount of quality and care put into the product.

It is possible to go on an entire voyage while building your own gun. Building enables you to entirely customize the pistol to meet your needs. Given that you choose every component, it is the choice with the most personalization potential. If you keep an eye out for sales, part selection may occasionally cost you less than it would for a factory-made firearm. Consumers who are able to resist the temptation for instant pleasure can find some incredible discounts online. It is also possible to grasp the platform and how it works by putting it together yourself, but this has its own set of challenges.

You need to be completely honest with yourself when deciding whether to build or purchase an AR-15. How much money are you willing to put into making your weapon? Given that I just stated that customers can save money on parts, that may seem contradictory. The investment entails not just a monetary outlay but also the time commitment required for assembly, troubleshooting, and other tasks.

Do you have the tools and knowledge necessary to correct your bolt-carrier group’s improper staking? Do you know what to check for when determining whether the barrel’s threads have been correctly finished? Can you tell if the machining was done correctly by looking at a lower?

Beyond purchasing parts, you will need to make a financial investment in tools. There is a minimum expenditure you’ll be required to make, despite the fact that I’ve published a list multiple times and that I’m aware Chad from School of the American Rifle has one organized into tiers. This presupposes that you intend to assemble your firearm in accordance with accepted standards for the industry.

To do this, you will need to set up at least $500 on tools alone (this could be slightly less if you find sales or buy things second hand). To put the gun together, it takes more than just grabbing a cheap armorers wrench and a hammer and holding them between your knees. The typical gun owner is not even aware of all the instruments that are required to avoid taking short cuts. It goes without saying that the more guns you build over time, the less burdensome this expense becomes, but does it make sense to acquire everything up front and end up paying more?

To begin with, there is a basic minimum set of instruments that you must purchase in order to complete tasks correctly. To hold the parts you are working on, you need a vice in the first place. You also need a clamshell block, a mag well block, and some form of response rod. Without this, you cannot apply the necessary torque to a part (and a torque wrench, so add that to the list as well). I’ve seen accounts of individuals trying to attach objects to different surfaces or hold them between their legs, but it simply begs for issues down the road when the specs are incorrect.

You will require a castle nut, barrel nut, and muzzle device specific wrench or an AR armorer’s wrench that can handle all three. For varied installations, a decent set of roll-pin starting punches and roll-pin punches will be required, and a set of center punches will either be necessary or very helpful depending on the parts you choose (some companies like Aero have started using hex head screws in place of some pins). There are other additional tools you will require, so this is not a comprehensive list; rather, it is a sampling to help you understand what is required so you don’t balloon out a roll pin or shear off the ear of a barrel nut.

What happens if you purchase your components and all the necessary tools but lack the skills to complete the task? Well, many will advise you to pick up tips as you go. That’s great, but how do you get your information? What movies are reliable in a world where information is sold and bought? What happens if you put everything together but it doesn’t work? How do you solve the problem? How do you handle the situation where you choose a number of pieces but were unaware of the tolerance stacking issue?

Please realize that my goal is not to convince you to take the initiative. Few things can compare to the satisfaction of making your own AR-15. You can gain a thorough grasp of the platform, how the components go together, and how the entire system functions by building your own AR. You will be able to work on your AR more effectively in the future for cleaning, replacing parts, and troubleshooting some faults if you put it together yourself. However, I do want you to know that unlike what many people say, these guns are not Legos.

You do suffer some other repercussions, there is a level of education and awareness required, and you will need to invest in tools. Many businesses will void parts warranties if they are installed incorrectly (this will vary wildly depending on the company). Are you prepared to postpone a project while you wait for that specific part you want to come back in stock since some parts are more in demand than others? Do you have backups ready in case you damage or lose a part during assembly? The responses to those inquiries explain why some people decide to spend money on an assembly service from a reputable armorer or business.

02 Nov
Articles

5.56 vs 300 Blackout | What’s the difference?

Chevy or Ford? .45 ACP versus 9mm? comparing 300 Blackout (BLK) to 5.56mm NATO The arguments go on and on.

Even while I can make a case for the automobile brand wars, conflicts over calibers frequently continue because each side’s arguments usually contain some kernels of truth.

The issue of context is another. These arguments are frequently fought in broad terms of what’s “best,” without any clear guidelines for how “best” is chosen. Are Bugatti Veyrons superior to Jeep Wranglers? No, not if your goal is to navigate a pack mule track up a mountain.

Let’s examine the 5.56mm NATO vs. 300 BLK debate in more detail.

Why Is There a 300 Blackout?

The.300 AAC Blackout cartridge was designed with three straightforward objectives in mind: to have ballistics that are comparable to those of the 7.62x39mm (AK) platform, to deliver more “stopping power” when fired from a short-barreled rifle or pistol, and to outperform 9mm alternatives in the subsonic velocity range.

The first objective seems simple, right? Why not simply produce an AR-15 upper with a 7.62x39mm barrel and chamber?

To begin with, that would be emulating our adversaries, and that tactic is rather pathetic. What’s more, the sharply tapered rounds won’t load into regular AR magazines. There is still the issue of the AR’s vertical magazine well, even if you swap the magazines with something more banana-shaped to suit the slanted Commie Cartridges.

Describe it.

In reality, the 300 BLK is a shortened version of the.223 Remington. Instead of using a.224-inch diameter bullet, the brass case is cut, reshaped, and extended at the mouth to fit a.308 bullet. The overall cartridge length is still suitable with regular magazines even if the bullets are longer and heavier than their.223 Remington counterparts.

We’ll see in a moment how important the implications of it are. The case’s dimensions and body’s diameter are both the same. Although the shapes differ, the overall lengths are similar.

Platform Variations

It doesn’t take much surgery to convert a normal AR-15 rifle chambered in 5.56mm to 300 BLK because the cartridges are so similar. Actually, all you need to do is switch out the barrel. On an AR rifle or handgun, that is a straightforward operation. The barrel nut simply pulls out for an effortless swap after removal.

The bolt and bolt carrier have not changed since the cartridge base has not altered. The magazines can be switched out for one another for the same purpose. A STANAG (NATO Draft Standardization Agreement) magazine can be used with 300 BLK cartridges without any modifications. Oh, there’s yet another advantage. In contrast to “alternative” AR cartridge options like the 6.8 SPC, magazine capacity is also the same.

Performance?

The bullet weight differential between 5.56 and 300 BLK is one to note. The weight of the “standard” 5.56 NATO bullet ranges from 55 to 77 grains. 110- or 125-gr. bullets are used in the majority of supersonic 300 BLK ammunition. Typically, the subsonic variant fires 220-gr. bullets.

Thus, a tradeoff results. While the heavier and thicker BLK bullets carry more energy downrange, the lighter 5.56 NATO bullets fire flatter over longer distances. More bullet drops are the price. The best option for you therefore depends on what matters to you the most.

To investigate how velocity and bullet drop carried with both the 5.56mm NATO and 300 BLK options, I ran the statistics with all four possibilities. The zero distance for both guns was set at 50 yards.

If you want to optimize the amount of energy on target, bullet weight is important. While the traditional unit of kinetic energy, the foot-pounds, represents destructive force, the companion unit of momentum, the pounds-feet per second, conveys an object’s capacity to propel another. Therefore, the BLK offering can be the correct choice for you if you’re searching for a heavier hit. The average muzzle velocity of 55- and 77-gr. 5.56 rounds is 22 to 28 pounds-feet per second. Projectiles weighing 125 and 230 g in 300 BLK range carry 36 and 33, respectively.

The cost of ammunition is another factor. The sheer volume of discharged rounds is advantageous for the 5.56 NATO globe. Companies invest more money to supply the market with countless billions of rounds the more people shoot it. As a result, you and I pay less per round. Both supersonic and subsonic 300 BLK cartridges typically cost more per round due to the reduced capacity of this caliber.

Did the.300 AAC Blackout accomplish what its creators had envisioned? In my opinion. The ballistics of the 300 BLK are comparable to those of the 7.6239, it performs well from a short barrel, and it outperforms the 9mm in subsonic and suppressed performance.

What is suitable for you? It’s similar to asking if you prefer two-wheel drive or four-wheel drive. For their respective applications, they both have benefits and drawbacks. The one that is best for you will depend on how you want to utilize it. Both the 5.56mm NATO and the 300 Blackout are effective defensive weapons.

5.56mm is more frequently utilized for small game and varmints in the world of AR-15 hunting, where fragmenting terminal performance is preferred. The BLK offers a more complete solution for larger games when penetration is more crucial.

The final verdict is this: lighter and faster versus heavier and slower. It sounds a lot like the argument between 9mm and.45 ACP, doesn’t it?

17 Dec
Articles

What is a Bolt Carrier Group (BCG)?

The AR-15 has a locking rotating bolt design, and the Bolt carrier group is perhaps the most important part of the rifle. The BCG, or Bolt carrier group is that actual part of the rifle that fires the round, apart from that the Bolt carrier group in an AR-15 serves the following purposes.

  • It contains the firing pin, which ignites the primer of the bullet and fires it.
  • It ejects the spent casing of the fired bullet
  • It loads a fresh round into the chamber
  • It recocks the hammer in the lower receiver, allowing the new round to be fired.

How does the Bolt Carrier Group work in an AR-15?

Now that we know what the bolt carrier group is supposed to do, let’s talk about how it does it. The BCG relies on the gases created by the fired bullet to operate. The gas travels from the barrel, through the gas tube, and reaches the bolt carrier key or gas key. This unlocks the bolt, and the gasses hit the bolt, moving it backward.

On the way back, the extractor takes the spent casing out of the chamber, and a spring-loaded ejector forces it out of the receiver. The hammer is also recocked after the round is ejected.

The bolt moves back into the buffer tube, where the buffer spring compresses. As it decompresses the bolt moves back forward, picking up another round from the magazine and chambering it. The bolt rotates to lock, and the rifle is ready to fire the next round.

The BCG keeps going through these steps with every round that is fired.

What are the parts of the Bolt carrier group?

Bolt Carrier:

The bolt carrier is like the primary housing that holds all the other components of the bolt carrier group. The carrier key or the gas key is also attached to the bolt carrier.

Bolt:

The AR-15 has a rotating bolt, which has locking lugs on it. The bolt rotates about 15 degrees and locks into the chamber. Then the bullet is fired, the bolt has to absorb the initial explosion, and keep it in the chamber. Therefore, bolts are made from forged steel.

Firing pin:

The firing pin rests inside the bolt. When you pull the trigger, the hammer falls on the firing pin, which strikes the primer of the bullet, and ignites it, firing the projectile through the barrel.  There is also a retaining pin with the firing pin, which keeps it in the bolt.

Cam pin:

The job of the Cam pin is to prevent the bolt from over-rotating when it unlocks because of the gas pressure.

Extractor:

The extractor takes the spent casing of the fired round out of the chamber. It hooks the rim of the round, and as the bolt moves back, the round is also extracted.

Ejector:

The spring-loaded ejector is located on the side of the firing pin. It maintains pressure on the round, and as soot at it is completely extracted, the ejector sends the spent casing flying out of the receiver

 

10 Dec
Articles

What are the Parts of an AR-15?

AR-15 style rifles are the most common rifles in the US, and one of the main reasons for this popularity and the rifle’s military adaptation and ease of maintenance. The AR platform rifles are very maintainable, and their parts are widely available. In fact, anyone with little knowledge could build an AR-15 at home using a parts kit.

If you want to do the same, or simply learn more about this incredible rifle, you need to know about all the parts that make an AR-15. So, let’s get into it.

The constriction of an AR-15 can be divided into three sections, the front, the receiver, and the buttstock. Here is an explanation of all the parts in each of these sections.

The Front:

Starting from the front of the gun, the first thing you will find is the muzzle device. Different devices like Compensators, Flash hiders, and suppressors can be installed on the Muzzle on an AR. Compensators help decrease muzzle rise, flash hiders eliminate the flash of the rifle firing, and suppressors decrease the sound of the gun.

Moving back, the next thing you’ll find is the barrel of the rifle, which is mostly made from stainless steel and can vary in length, however, it has to be at least 16 inches according to the Law in the US.

The barrel is covered with the handguard, which is usually made of polymers and has Picinati rails or M-Lok to mount accessories. The handguard also houses the gas block and gas tube. The AR-15 and other similar rifles are gas-operated, which means that when a round is fired, some of the gas from the barrel is redirected to the bolt carrier group, which moves backward due to the gas pressure, ejecting the fired casing, and on its way back chambers another round. This is what makes the AR-15 semi-automatic, or in the case of the M4 or M16, automatic.

The Receiver:

The receiver can be divided into two sections, the upper receiver and the lower receiver. The upper receiver of the AR-15 contains the bolt carrier group, charging handle, forward assist, and rear sights. The bolt carrier group is made up of several smaller parts, including the firing pin, the extractor, bolt, cam pin, and the gas key. Combined, all of these parts are responsible for loading your rifle after it is fired. The bolt moves back into the buffer tube after a bullet is fired, extracts the spent casing while moving back, and loads a new round coming forward.

The charging handle is a part of the upper receiver, which is used to manually cycle the bolt to load the rifle and the forward assist is there to improve reliability. If the bolt isn’t closing completely for some reason, the forward assist can help you close it.

The lower receiver contains the trigger group, magazine well, magazine catch and release, the safety selector, and bolt release. The trigger group consists of the hammer and the trigger, pulling the trigger releases the hammer, which hits the firing pin, and ignites the primer of the round.

The magazine well holds the magazine and the magazine catch keeps it in place. The safety selector is self-explanatory, it either blocks the trigger or allows you to shoot depending on its position. In M4s, the safety selector also has a full-auto option.

The AR-15 has a last round bolt hold open, so after a magazine is emptied, and you enter a new one, you don’t need to rack the charging handle every time, and can instead press the bolt release to allow the bolt to come forward, and have your rifle ready to fire.

The Buttstock:

The only functional part of the buttstock is the Buffer Tube. When the bolt moves backward, it has to go somewhere, so it goes into the buffer tube, which also has a recoil spring in it to absorb some of the recoils of the gun.

So, these are the parts that make up the amazing and super popular AR-15 rifle.

03 Dec
Articles

What Trigger Group is Best for My Build?

The trigger group is one of the most influential parts of your AR-15 when it comes to accuracy and weapon performance. There are loads of aftermarket triggers in the market, which have different pros and cons, and deciding which one is ideal for you can be a little challenging.

Your ideal trigger depends upon a lot of factors, and how you tend to use your rifle. Moreover, personal preferences also need to be considered to make sure that you get the best trigger group for you.

Here are some things you need to consider to find the best trigger group.

Single-stage Vs Dual Stage triggers.

In simple words, a dual-stage trigger fires in two stages. When you start pulling the trigger, the first stage has a stronger trigger pull, then you enter an intermediate area with a very slight resistance to pull the trigger. Single-stage triggers are a lot faster than dual-stage since they don’t have that intermediate area.

According to experts, dual-stage triggers are better for long-range accuracy, whereas single-stage triggers are better for close-up action, where you need to fire multiple shots quickly.

So, that is something you need to consider. If you are doing some long-range target shooting, then a dual-stage trigger would be better, but for competition shooting, where you need to land quick shots, a single-stage trigger is better.

Trigger weight:

The next important factor to consider is trigger weight. This is the amount of force it requires for you to pull the trigger until the hammer falls and fires the gun.

When it comes to competitive shooting, lighter triggers are the best. Match grade triggers are light and crisp, which means that there is almost no play in the trigger, and it fires with a very small force.

On the other hand, when it comes to self-defense, and actual close-quarters combat, light triggers aren’t the best option. Lighter triggers are easier to accidentally fire when moving around. This is why most mil-spec AR-15s and M4s have heavier triggers, typically around 6.5 pounds. On the other hand, competition triggers can be as light as 2 pounds.

However, longer triggers aren’t particularly great for accuracy, since they cause the shooter to anticipate the recoil, which can cause them to flinch, and take the rifle off sight. Some people use longer triggers, and press them near the breaking point until they are ready to shoot when they pull the trigger completely. Though this can be effective, it requires a lot of practice, and only a trained marksperson can do it right.

So, if you are a competition shooter, a light trigger group is best for you, and if you are using your rifle for home defense, or combat, a heavier trigger pull is the better option. A 4 lbs trigger is a good middle-ground for an all-purpose rifle.

Curved Vs Flat triggers:

Some trigger groups have standard curved triggers like seen on most rifles, and AR-15s, however, some people also prefer flat triggers. Neither has any significant tactical advantage or disadvantages, at the end of the day it does come down to preference, and whichever trigger feels better in your hand.

 

 

26 Nov
Articles

What is a Charging Handle?

Every semi-automatic rifle needs to be loaded, and the chagrin handle plays a very important role. The charging handle manually charges or loads the rifle, cocks the hammer, and gets the rifle in the ready position, hence it is called the charging handle.

Charging handles come in different sizes and shapes on different firearms. In some rifles, like the AK, the charging handle is an integrated part of the bolt carrier, and hence it moves back and forth with it. Such charging handles are called reciprocation handles. In other rifles, like the AR-15, the charging handle is non-reciprocating, which means it does not move with the bolt.

In the AR-15, the charging handle is located in the back, above the buffer tube, and under the rear sight block. It is a T-shaped handle, and when it is pulled, it brings the bolt back with it, against the tension of the recoil spring in the buffer tube.

When the charging handle cant be pulled anymore, you release it, and it allows the bolt to move forward, picking up a round from the magazine, and chambering it.

When do you need to use the charging handle?

The charging handle on an AR-15 serves many purposes. The AR-15 is a self-loading rifle, still, when you load a magazine, you need to charge the bolt manually so that the first round can go into the chamber. After that, all the rounds are loaded by the operation of the bolt.

The charging handle is also used to clear malfunctions and stoppages. For instance, if you have a bad round in the chamber that won’t fire, you can manually load another one using the chagrin handle. Other stoppages like failure to feed can also be cleared by pulling the charging handle.

You can also use the chagrin handle to make sure that the rifle is clear when you are cleaning or maintaining it indoors.

Why would you need an upgraded charging handle?

Most AR-15s come with mil-spec charging handles, which are usually right-handed. These charging handles are ideal for any normal shooter, but in some cases, competition shooters, or AR enthusiasts like to get aftermarket charging handles.

Some left-handed people also need to change their charging handles, or they can also opt for competition ambidextrous charging handles

Most competition shooters, and tactical enthusiasts who train with their AR-15s, opt for extender AR charging handles. These charging handles have an extended latch, which is easier to grab in the dark, or when you are wearing gloves.

Though the standard mil-spec charging handles aren’t bad at all, one of the best things about the AR platform is that there is an incredible aftermarket for its parts, and you can get some really good charging handles if you want.

29 Aug
Articles

A Comparison of the AR-45 ACP vs AR 9mm

If you want to build a custom pistol caliber AR, there is one major decision to make first. Do you want to build it in 9mm or .45 ACP. There are differences and benefits to both. Lets Review them and go from there.

9mm, which is one of the most commonly used rounds today in the world, is always a favorite.The benefit of the 9mm is the controllability and the capacity, not to mention that these days it is fairly inexpensive to shoot.Some believe the 9mm is better for home defense because it will not penetrate as much as the .45 acp The 9mm also has less felt recoil than the .45 acp. 9mm has been used in our Military for over 30 years, and continues to be used today.

For the .45 ACP, the round has survived two World Wars, Korea, Vietnam, and has been used in our military up to the 1980s. Famous for major stopping power. It does have more penetrating power than the 9mm, and some believe bigger is better.

It is personal preference and either one makes a good choice for building an AR pistol or rifle.

29 Mar
Articles

6.5 Creedmoor VS .308 Cal

There are alot of people moving into the 6.5 Creedmoor category, moving out of the .308 game. The 6.5 Creedmoor uses skinnier, lighter bullets and its faster downrange than a .308.

However, the 6.5 Creedmoor is very popular as a great selection for medium to long range (500-1000 yards) shooting. Which is why the military has added this caliber   into some of their rifles for long range targets shooting.
Ballistics speaking, the skinny 6.5mm bullets perform exceptionally well, very closely matching the ballistic profile of a 300 Winchester Magnum, but with much less recoil and cost.

It’s possible that the popularity shift to the 6.5 Creedmoor, is the better ballistic cartridge than .308 Cal due to performance consistency. The .308 was designed in 1952 for a semi-automatic military rifle, while the 6.5 Creedmoor was designed in 2007 for better long range target performance in a bolt action rifle. Which now has evolved into the AR platform of weapons

07 Jan
Articles

Cerakote Finishing vs Anodized Finishes

There are many colors and finishes to choose from, when building and accessorizing a custom AR15. With over 13 different colors to choose from, 9 cerakote colors and 4 anodize colors, a lot of customers do not know where to start. First determine what colors you like, then choosing anodize or cerakote will help you narrow it down.

Cerakote finishing is a paint , that is sprayed then baked on. By baking it, it does allow the paint to become hardened, which makes is somewhat scratch resistant. It will hold up over time with normal wear and tear. However, it can be scratched or scraped, so hard use will show if the rifle is dropped or damaged. The paint has to be applied evenly, but the finished product is usually very smooth.

Anodize Finishing is a chemical finishing, that is embedded in the material. A standard AR15 rifle is a anodized black finish. So now instead of black, you can get that same factory finish in a variety of colors such as green, purple, blue, and red. Benefits of this finish is that it will withhold against cleaning chemicals well, and there will not be any possible scratching , paint run marks, or chipping. Sometimes the anodize colors will vary on each part, depending on the type or grade of aluminum that is being used. That is the only possible downside.

06 Jan
Articles

.223 Remington vs 5.56 NATO (5.56 x 45mm)

We have alot of customers that ask us what is the difference between the .223 Remington caliber and the 5.56 Nato caliber. They are concerned about which ammo to buy and which they can shoot safely in their rifle. We are going to explain the difference.
The common mistake people make is that they think the two are the same.  5.56 Nato and .223 Rem are in the same family, but still different. This can be a problem and lead to a dangerous situation. The case dimensions are the same, but there are enough other differences that make the two not completely interchangeable.
One big difference is pressure. Another big difference is length. 5.56 Nato , or 5.56 x 45, is slightly larger than a .223 Remington.

Customers ask what is safe? It is safe to shoot .223 Remington cartridges in any safe gun chambered for 5.56×45 mm. But also, it is not recommended and it is not safe to shoot 5.56×45 mm cartridges in a firearm chambered for .223 Rem.

When shooting .223 Rem. cartridges in a firearm chambered for 5.56×45 mm, it’s likely the shooter will lose accuracy and muzzle velocity.

What does this mean to you? If you have an AR-15 rifle chambered in 5.56×45 mm, you can shoot either .223 Remington or 5.56×45 mm safely. If your barrel’s twist rate is 1:7″ you should use bullets weighing 60 grains or heavier. If you have any rifle with a 1:12″ barrel twist you should use bullets of 60 grains or less for best accuracy. If you have a .223 Rem. rifle of any type, it is not recommended and not safe to use 5.56×45 mm ammo.