Is 5.56 the Best Option for Everyone?

Many people love the AR-15. If you are not one of them, then a large number of gun enthusiasts might tell you to go pound sand. The platform is versatile, deadly, readily available, and somewhat affordable. When shoppers first start looking at battle rifles, they tend to start at the bottom and eventually work their way up. Would be owners quickly realize that like most things in life, you get what you pay for. Entry-level ARs are often .223/5.56 semi-auto rifles with few to no options, and sometimes-shoddy construction. Guns that are more expensive offer rails with endless accessories, as well as different calibers. Just when you thought you knew everything there is to know about the AR-15, they change it up. So is a high end AR chambered in a wildcat or alternative caliber a good idea?

Shooters from all walks of life praise and denounce the 5.56/.223 for a variety of reasons. It is easy to find rumors on the internet about the lack of lethality of the 5.56 NATO round. You might be familiar with a few:

  • Ineffectiveness at long range
  • Inconsistent wounding effect
  • Poor intermediate barrier penetration
  • Ease of deflection

The fact is that there are no official documents stating that the 5.56mm NATO caliber has failed in any NATO military force. On the contrary, we have official documents stating that there is no issue with the lethality of the 5.56mm caliber at all. Most NATO nations even agree that the next generation of small arms weapons by 2020 will still be using the 5.56mm NATO caliber.

So why on earth do shooters sometimes shell out big bucks to own AR platform rifles chambered in 7.62×51 NATO, .300 AAC Blackout, or the 6.8 mm Remington SPC? The answer is simple, they can! Most people I know who own an AR-10 or wildcat AR-15, already have at least one rifle chambered in .223/5/5.56 NATO. This frees them up to branch out into different areas. Having a good old .223 rifle around is good for emergencies, and as far as availability goes, the .223 is one of the most common rounds a person can find in the United States. However, some shooters prefer a bit more performance out of their battle rifles, hence the larger caliber market.

So which one should you buy? Well it depends on what is important to you. While no caliber is perfect for everything, some do certain jobs with a bit more reliability. The .300 AAC Blackout is my favorite. It will give you an entirely new caliber with nothing but a barrel change. The same magazines and internal components in your current 5.56 rifle will do just fine.


  • More muzzle energy than 5.56 NATO
  • Able to be suppressed more effectively than 5.56
  • Uses a larger bullet for more damage to target
  • Able to penetrate barriers more effectively
  • Supersonic and subsonic ammunition available
  • Swapping between supersonic and subsonic requires no changes to the gun
  • Can be made from 5.56 brass, easy to reload


  • Ammunition is not widely available
  • Ammunition is currently slightly expensive

The 6.8 SPC isn’t a terrible option either. It falls at about the halfway point between the 5.56 and the 7.62×51. You get a little better ballistic performance than the .300 AAC Blackout, but you have to change out your AR parts. If money were no object, the 6.8 would be an outstanding choice for a supercharged AR.

Then we have the good old 7.62x51mm NATO. The civilian version, the .308, is one of the most successful cartridges of all time. It’s big enough to drop big game, but small enough to deliver relatively light recoil. It is an almost ideal sniper round, and the U.S. Army’s M14 sported the cartridge. Additionally, the original AR rifle that Eugene Stoner designed was a 7.62×51. So why doesn’t everyone carry an AR chambered in .308? Cost is one factor—you have to shell out twice as much money for a .308 AR. Have you checked the price on .308 ammunition lately? Even if I were a rich man, I still wouldn’t shell out that kind of money for brass, smoke, and noise. If that wasn’t enough to keep buyers away, most .308 magazines carry 20 rounds instead of 30. Weight is another issue, since AR-10s are extremely heavy and carrying all that heavy ammo can be a real pain.

Therefore, it is ultimately going to be up to the buyer. There is no such thing as a bad AR cartridge. Most any of the oddball calibers will do fine in a combat scenario. However, due to the much lower cost and availability of the 5.56, my second AR might end up being the same cartridge as my first.

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Comments (13)

  1. I am one of those old Vietnam Vets that had to actually have someone come tot he field to remove my M-14 from my hands and give me the M-16. I love the M-14 but… fickled… I also love the AR platform as well.

    I have 4 of these “NASTY” black rifles. Bought 2, built 2. 2 are in the 223/5.56 mode, one in the 308 mode and one in the 300 Blackout. Cherished place in my gun safe for all. Ammo is no issue. My son is a state cop and I get the 45acp/223/38spl( prison guards use them) brass from their qualifications twice a year. So brass is plentiful. As far as 300 Blackout… I reload all of these. I cut the 223 cases and resize for the 300…so I avoid a lot of the costs of buying 300s. So…if you have one or more of these AR platforms…maybe expand your pleasure by taking up reloading. It helps feed these “hungry” weapons. LOL

  2. I enjoy coming across articles that bring out the thoughts of 223 and 308…

    I grew up learning 22 long rifle.. that is. what my dad said. will make you good. spotting Jack Rabbits and Coyotes . 3 and 4 times a week on our Kansas ranch. The old incandescent spot light, plugged into to lighter socket in a Jeep J10; memory’s of a mission. We drove in the fresh cut wheat fields circling, looking and there it was. We stop i lean out the window, Dad would be ” Go! aim, Shoot” took me one night and missing 3 and all fell in place 3 more went down like clock work at 100 yards or better and we started a stew every week. My dad is now 85 and and I am 46. We went out with my 308 and 223 to get some stew with, Ha! led lights and nailed a few Rabbits he is still as cool a shot as ever. That is of course to his fine military training. Cheers Justin and Larry Doskocil

  3. The only reason I have rifles chambered in 5.56/223 is because there has always been a good supply of ammo at competitive prices. I prefer the .30 caliber cartridges for the range and for hunting. There are much better combat rounds also.

  4. My choice is the 7.62×39. Why? I have owned one of the best ARs I’ve seen by Rock River and it was GREAT, but when compared to an Arsenal SAM 7 AK it does not hold up as well for battle. With the SAM7 I get a 2-3 MOA with surplus ammo and better with match. That’s good enough for battle. With the 7.62 I can go through bushes, trees, walls, cars and all sorts of things to get to my foe on the other side. When I went with cheapie ammo in the AR…jam..bang…jam. When I use the crappiest ammo in the AK..bang…bang…bang. One more note, you can find 7.62×39 lying around on the ground in most countries. JMHO

  5. You showed the 7.62 x 39 as an option for the ar-15 but didn’t review that caliber, just the 7.62 x 51. What is your opinion on that option? I will be starting a build and was going to go with the 7.62 x 39 caliber since I used to own an sks and enjoyed shooting it a lot. Plus the cost of ammo is still cheaper and heavy enough for hunting purposes.

  6. While both my current AR are .223, there are a few “wildcats” I would rather go to than the 6.8, or even the .308. My first choice would be the 6.5 Grendel. Better BC and will get out to well over 500 yds. Then there is the heaviest hitters in the AR platform: the .50 Beowulf. If you ever need to punch gaping holes in your target, this miniature cannon will do the trick. Short on range, but heavy in punch! Would love to build some uppers in these calibers, since I reload, I guess I don’t look at lack of commercial ammo to be too much of an issue.

  7. Yup , my vote would be for the .223/5.56 round for a number of reasons , some mentioned above by the other fellow`s . I`m from the old school though , I don`t much care for the AR platform rifles , Although there pretty good rifles , I myself belive in the old platform rifles….. Like the M~1/M~1A action Esp: for dependabilty . They just keep on firing no matter how nasty they get …. Sand , Dust , Mud , Ect. Ect. won`t efect them , And it`s an All” Steel proven action that you can damn near Not” ware out , instead of Alum action platforms . So those are the main reason`s , my chouse for an all around battel rifle , is the Mini~14~580 model ser. up with the 5/8 in. heaver barrel / and with the 20 round mag`s . Although the 30 round mag is a hell of a lot better in a combat type rifle , the 30 round mag`s in a .223/5.56 rifle , is just not depenable enough to suite me , At least I`ve never seen one made yet that was COMPLETELY” Dependable , so I use the 20 rounders , I peferabley Steel mag`s . I have 30 of them in my battel group , and they all preform Flawlessly . The .223/5.56 round preforms work Just fine in a fire fight , and it`s a plentful , cheap round to be using for an all around battel rifle , Esp:…. If you do your own loading of the round , it`s a hell of a lot cheaper to use , than the 7.62 cal`s Up . Is the .308 round in a battel rifle Better …. Hell YES” , it is , in an all Steel Action battel rifle like the M~1A ….. Hell YES” , will the extra carry weight on a man of the 7.62 cartrage slow you down …. Hell YES” , will the extra cost of the 7.62 rifle and it`s ammo , pinch your pocket book …. Hell YES” , will it cost you a lot more to buy or reload your own 7.63 ammo …. Hell YES” , is 7.62 ammo plentful …. Hell YES” . Can I aford it …. Hell NO” , I chouse a .223/5.56 battel rifle and ammo for my need`s , IF” , I Ever Have To Use It For A Battel/Fire Fight Rifle .

  8. Basing my experience in the military and my personal choices for firearms, my answer to “Is 5.56 the Best Option for Everyone?” is “5.56 is the best option for most people.” When developing the M16/5.56, the US Government came to the realization that most firefights occurred at ranges less than 300 meters and had to walk longer distances to get to firefights. Prior to Vietnam, personal engagements were at farther ranges, up to 1000 meters and “the line” changed infrequently which meant less walking overall. Guerrilla and jungle warfare opened up a new need for weaponry abroad so the heavy. longer range weapons were phased out and replaced with the current M16/M4 family. As Gman said, most soldiers on patrol will rarely fire their personal weapons. More or less this is true due to crew serve and truck mounted weapons (M240B, M2, Mk19) taking part in most engagements. But there are still soldiers who rely on their M4/M16 and in my case a few times, M9. Are there engagements where 5.56 falls short? Yes. But we have other assets for that. But that is military world. For civilians I see 5.56/.223 as a very good “middle of the road” caliber. You can teach your wife or 7 year old daughter to shoot it because the recoil is so manageable. Most bolt action hunting rifles are zeroed at 100 yards but the 5.56 travels roughly 3x that distance so the round is still an effective deer round. And 5.56 is a very good self defense round as far as damage to an enemy goes. The 5.56 is a great balance round. If you want something better, save up your pennies and buy it.

  9. I also agree with CTD Rob, I still don’t know what caliber is best, but I think maybe the 5.56 is good enough for most situations. Keep the info coming!

  10. After 30 years of military service, I can say the average troop will never fire their AR outside of qualification requirements at the range. My point is that personal experience regarding the AR’s effectiveness should come from those that have had to fire in sustained combat which resulted in confirmed kills, wounded, and misses.

    When a government is faced with arming large amounts of troops for combat, it is an unfortunate aspect that a cost vs. effectiveness ratio has to be factored into the decision making process. Overall, the U.S. Government has done the best it could to provide the highest quality weapons platforms and accompanying ammunition, balanced against the cost to the tax payer. Within that realm of thinking, and throughout history, different weapons platforms apply to different specialties. For example a soldier assigned to an LP/OP or a recon patrol or a sniper etc. — each has distinctly different roles. The weapons systems vary from light-weight to heavy weaponry which may even require an assistant gunner. Even within a specialty there are different platforms and rounds for different targets; for example a sniper primarily uses a 7.62, but can fire anything from a 5.56 up to a .50 Cal. depending on the environment and the target which could be human or armored vehicles.

    But I digress in that the question was, “Is 5.56 the Best Option for Everyone?” The process for one to decide this is not much different than that which our government goes through. What is your personal economy? What can you afford at the time of purchase? Like the U.S. Government, this most certainly is a factor. Which is the most effective platform and caliber of ammunition that your economy (personal budget) can afford to get the job done? I would have to say that many would agree that the 5.56 is all around the best average choice for most people. If you can afford better, then get it.

  11. I essentially agree with the original comments as posted by CTrob. Since I first learned to handle an M-16 back in the day during Vietnam, I will always harbor a suspicion that the damn thing will go belly up when I need it. It turns out the fools at the Pentagon (including the late Robert McNamara) were totally wrong when they issued these “black rifles” w/o cleaning kits. Yep, they did!!! No one will ever know how many grunts got hit as a result. However, they had the right idea for jungle fighting. I will always love the M-14 and the .308W cartridge and I’m glad to see this fine weapon has made a comeback as a sniper rifle in the “sand box”.

    As for calibers in the M-15/M-16, I still love the .308(7.62X51mm) If I was forced to choose another caliber I would go with the .300 Blackout. It’s a non-standard caliber now, but it might just catch on. If not, buy/load a lot of ammo and enjoy!

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