Choosing a Load for Your AR: America’s Rifle

Several rifle bullets of different calibers in a straight line

The AR-15 is America’s rifle, and it fires the single most popular caliber in America. While there are other AR rifle calibers, the .223 Remington is more popular than all the rest put together. The AR-15 rifle — or KelTec’s SU16 and Ruger’s Mini-14 — is well suited to a variety of chores including pest shooting, varmint hunting, personal defense, competition, and in some cases, the taking of medium-sized game.

Interestingly enough, all of the chores the AR-15 is suited to demand good marksmanship. After all, the AR-15’s excellent handling compliments a trained shooter. The .223 Remington cartridge will vaporize a varmint at 300 yards — if you can hit the small target. And taking a deer with the .223 is easily done with good shot placement.

Federal 62-grain Green Tip ammunition
Federal’s 62-grain Green Tip is an accurate load.

The AR is also a versatile rifle that will perform many other chores well too. Changing the optics and load allows the shooter to address many needs with a single rifle.


It’s easy for a novice to be confused about the different AR loads available and their uses. Poor recommendations in the popular press have not helped. While we may address the choice of practice ammunition with whatever is cheapest, that isn’t the whole story — although it is certainly part of the story. Also, keep in mind that the 5.56mm NATO and .223 Remington, while identical in dimension, are not quite the same.

The 5.56mm is loaded to greater pressures. The cartridge case is thicker in some cases with the 5.56mm and may run to higher pressures with the same amount of powder. If you handload, know what you are doing with load selection. However, that is a different story. In this report, we are looking at ammunition performance.

For range use, there is some truth to “whatever is cheapest.” As a rule, steel-cased ammunition is less expensive. It is usually dirtier as well. Steel cases may be harder on the extractor. For long-term storage, steel cases seem more susceptible to the elements.

Just the same, for running a few hundred cartridges through the Springfield Saint in a single range session, steel-cased ammunition is hard to beat. After all, if the rifle runs well with steel case loads, why not use them? You simply should not expect the best reliability and accuracy.

Hornady Full Boar .223/5.56 ammunition
Hornady Full Boar is a great all-around hunting load.

Then we have brass-cased Winchester, Federal, Remington, Hornady, and other loads. These loads usually use a 55-grain FMJ bullet, some use a 62-grain bullet. These loads are more than accurate enough for meaningful target practice. The American Eagle loading is just about as accurate as much more expensive match-grade loads.

Brass case 55-grain FMJ loads are among the most useful practice loads. And, while I prefer a different load for personal defense, the 55-grain FMJ loading is more than effective at close range. The high velocity often makes the projectile break in half at typical defense ranges.

Let me recap. If the barrel is marked 5.56mm, all loads are useful — .223 or 5.56mm. If marked .223 use only, use .223 Remington loads exclusively. The .223 Wylde chamber is useful with either cartridge. That is a basic amount of knowledge you must have squared away before you choose a working load. However, this article is about individual classes of AR-15 rifle loads.

Man wearing Walker's Game Ear hearing protection shooting an AR-15 rifle
The primary concern is always reliability.

Varmint and Pest Loads

I have seen the Varmint Grenade, a very fast 36-grain bullet, do the business by blowing up varmints. This load rapidly expands and vaporizes varmints. The 40-grain V-Max is much the same. The Federal 40-grain Blitz is another superbly-effective choice.

A caution… despite the recommendation of those who should know better, never use such light AR loads for defense. They may blow up on the lightest resistance such as a cell phone in the pocket or belt buckle. This is their design.

Winchester 55-grain FMJ white box ammunition
Winchester’s 55-grain FMJ is a great recreational loading.

The AR may sometimes short cycle with these loads, especially when the rifle is dirty. For the intended purpose, the ultra-light loads offer instant effect and a degree of safety. They tend to break up rather than deflect, a trait of most .223 ammunition. They are highly unlikely to ricochet as they blow up on light resistance.

Longer Range Varmints

50 to 55-grain bullets such as the Hornady V-Max are ideal for longer range use. I have fired a good number of 40-grain loads, but far more of the 55-grain loads. At least in my rifles, the heavier bullets are more accurate. A V-Max bullet is reliable in expansion well past 300 yards.

Heavy Bullets

Based on good-to-outstanding accuracy and proven effectiveness, among my favorite AR loads is the 69-grain Sierra Match King. These are great when loaded by Fiocchi or in a handload. The balance of expansion and penetration is ideal, and accuracy is simply amazing in the right rifle.

The 77-grain bullets have earned an excellent reputation and would be a good choice as well. For home defense, a 55-grain JSP is probably the best choice. The load has proven effective and expands well, while offering far less chance of ricochet than most loads.



Velocity (FPS)

Penetration (inches)


Hornady 35-grain NTX3,2787Fragmented
Varmint Grenade 36-grain Handload/Varget Powder3,8005Fragmented
Fiocchi 40-grain V-Max3,5905.5Fragmented
Buffalo Bore Sniper 55-grain JSP2,9398Fragmented
Federal 55-grain Bonded2,90214.34
Federal 62-grain Fusion2,80912.55
Hornady 55-grain GMX2,91215.40
Barnes TSX 55-grain2,89016.5.5
Winchester 55-grain Silvertip2,8507Fragmented
Gorilla Ammunition 69-grain Sierra2,78114.4
Buffalo Bore 77-grain HPBT2,76711.36

The .223/5.56mm soft point penetrates less in a soft target and is less prone to ricochet than most pistol bullets. The result is greater safety. The rifle also has much greater hit probability, making for an excellent all-around home defender.

When choosing a load, first consider the likely duty. If I could have only one loading for every duty, it would (most likely) be a 55-grain JSP. However, I am glad that I don’t have to narrow my choices.

The performance of your AR-15 can easily be improved by choosing the load for your barrel twist, range, and mission. What are your favorite AR loads and uses? Share your answers in the comment section.

  • Bob Campbell in uniform shooting an AR-15
  • Man shooting a Ruger Mini-14 rifle at an outdoor shooting range
  • Winchester 55-grain FMJ white box ammunition
  • Steel-cased ammunition in a magazine showing rust on the cartridge case
  • Colt AR-15 .223/5.56 rifle with collapsible stock, left profile
  • Several rifle bullets of different calibers in a straight line
  • fragmented upset .223 bullet with an unfired cartridge
  • cutaway illustration of a .223 Remington cartridge
  • Hornady .223 55gr training ammunition
  • Hornady Full Boar .223/5.56 ammunition
  • Federal 62-grain Green Tip ammunition
  • 10 loaded AR-15 magazines with a box of Hornady 55-grain ammunition
  • Man wearing Walker's Game Ear hearing protection shooting an AR-15 rifle

About the Author:

Bob Campbell

Bob Campbell’s primary qualification is a lifelong love of firearms, writing, and scholarship. He holds a degree in Criminal Justice but is an autodidact in matters important to his readers. Campbell considers unarmed skills the first line of defense and the handgun the last resort. (He gets it honest- his uncle Jerry Campbell is in the Boxer’s Hall of Fame.)

Campbell has authored well over 6,000 articles columns and reviews and fourteen books for major publishers including Gun Digest, Skyhorse and Paladin Press. Campbell served as a peace officer and security professional and has made hundreds of arrests and been injured on the job more than once.

He has written curriculum on the university level, served as a lead missionary, and is desperately in love with Joyce. He is training his grandchildren not to be snowflakes. At an age when many are thinking of retirement, Bob is working a 60-hour week and awaits being taken up in a whirlwind many years in the future.

Published in
Black Belt Magazine
Combat Handguns
Rifle Magazine
Gun Digest
Gun World
Tactical World
SWAT Magazine
American Gunsmith
Gun Tests Magazine
Women and Guns
The Journal Voice of American Law Enforcement
Police Magazine
Law Enforcement Technology
The Firearms Instructor
Tactical World
Concealed Carry Magazine
Concealed Carry Handguns

Books published

Holsters for Combat and Concealed Carry
The 1911 Automatic Pistol
The Handgun in Personal Defense
The Illustrated Guide to Handgun Skills
The Hunter and the Hunted
The Gun Digest Book of Personal Defense
The Gun Digest Book of the 1911
The Gun Digest Book of the 1911 second edition
Dealing with the Great Ammunition Shortage
Commando Gunsmithing
The Ultimate Book of Gunfighting
Preppers Guide to Rifles
Preppers Guide to Shotguns
The Accurate Handgun
The Mission of Cheaper Than Dirt!'s blog, The Shooter's Log, is to provide information—not opinions—to our customers and the shooting community. We want you, our readers, to be able to make informed decisions. The information provided here does not represent the views of Cheaper Than Dirt!

Comments (2)

  1. Great article. I would like to add a couple of points:

    1. To maximize accuracy, it is important to try and match bullet weight with the twist rate of your barrel. Heavier bullets are generally more accurate out of barrels with higher twist rates, because they need more “spin up” to achieve good spiraling. Lighter bullets such as the ubiquitous 55-grain loads can achieve optimal spin with slower twist rates, and can actually destabilize in flight if spun too fast, causing accuracy to suffer. Consider that the M4 used by our military has a 1:7 twist rate, which is sufficient for the standard 62-grain M855 bullet while also being able to stabilize heavier bullets in the 68- to 77-grain range. My S&W MP-15 Sport 2 has a 1:9 twist rate, so I use 62-grain loads (when I can find them at a reasonable cost) for range and duty ammo.

    2. Many, if not most, indoor ranges will not allow the use of M855 “green tip” 5.56/.223 ammo. This is a steel core bullet designed for penetration of light to medium obstacles (think car doors), and over time will accelerate the degradation of a backstop. M193 ammo is a lead core FMJ bullet, softer on impact than the M855, so a better choice for indoor ranges.

  2. My favorite practice ammo is the Federal 55 grain ‘frangible’ load. Good accuracy and perfect for plinking steel targets leaving very little damage. They simply poof into a powder, practice perfection!

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