Guns & Patriots

.223 Remington vs. 5.56 NATO: What You Don’t Know Could Hurt You

Is firing a 5.56 NATO cartridge in your .223 Remington chambered AR15 dangerous?  Or do Internet forum-ninjas and ammunition companies selling you commercial ammo instead of surplus overstate the dangers?  Believe it or not, a real danger exists, and some gun owners who think they are doing the right thing may not be safe.

The Cartridges

The .223 Remington and 5.56×45 NATO cartridges are very similar, and externally appear the same.  But there are some differences that lie beneath the surface.

The 5.56 case has thicker walls to handle higher pressures, meaning the interior volume of the case is smaller than that of a .223.   This will alter the loading data used when reloading 5.56 brass to .223 specs.

Some 5.56 loads have a slightly longer overall length than commercial .223 loads. 

The Chambers

The significant difference between the .223 Rem and 5.56 NATO lies in the rifles, rather than the cartridges themselves.  Both the .223 and 5.56 rounds will chamber in rifles designed for either cartridge, but the critical component, leade, will be different in each rifle.

The leade is the area of the barrel in front of the chamber prior to where the rifling begins.  This is where the loaded bullet is located when a cartridge is chambered.  The leade is frequently called the “throat.”

On a .223 Remington spec rifle, the leade will be 0.085”.  This is the standard described by the Sporting Arms and Ammunition Manufacturers’ Institute, Inc. (SAAMI).  The leade in a 5.56 NATO spec rifle is 0.162”, or almost double the leade of the .223 rifle. 

A shorter leade in a SAAMI spec rifle creates a situation where the bullet in a 5.56 NATO round, when chambered, can contact the rifling prior to being fired.  By having contact with the rifling prematurely (at the moment of firing), chamber pressure can be dramatically increased, creating the danger of a ruptured case or other cartridge/gun failure.

The reverse situation, a .223 Rem round in a 5.56 NATO gun, isn’t dangerous.  The leade is longer, so a slight loss in velocity and accuracy may be experienced, but there is not a danger of increased pressures and subsequent catastrophic failure.

How serious is the danger of firing 5.56 ammo in .223 guns?  Dangerous enough that the SAAMI lists 5.56 military ammo as being not for use in .223 firearms in the technical data sheet titled “Unsafe Firearm-Ammunition Combinations.” 

ATK, the parent company of ammunition manufacturers Federal Cartridge Company and Speer, published a bulletin entitled “The Difference Between 223 Rem and 5.56 Military Cartridges.”  In this bulletin, ATK stated using 5.56 ammo in a .223 rifle could result in “…primer pocket gas leaks, blown cartridge case heads, and gun functioning issues.”

However, the danger may be lower than SAAMI or ATK suggest.  In Technical Note #74 from ArmaLite, the company states “millions of rounds of NATO ammunition have been fired safely in Eagle Arms and ArmaLite’s® SAAMI chambers over the past 22 years,” and they have not had any catastrophic failures.

According to ArmaLite:

“Occasionally a non-standard round (of generally imported) ammunition will fit too tightly in the leade, and resistance to early bullet movement can cause elevated chamber pressures.  These pressures are revealed by overly flattened primers or by powder stains around the primer that reveal leaking gasses.”

What Do You Have?

So, if you own a rifle chambered for the .223 for 5.56, do you know for which caliber it is really chambered? 

Many match rifles are chambered in .223 Remington (SAAMI specs) for tighter tolerances, and theoretically better accuracy. 

Many of the AR-15’s currently sold on the market are made for the 5.56 NATO cartridge.  If you own one of these, you should be fine with any .223 or 5.56 ammunition.

However, ATK dropped this bomb in the bulletin on the .223/5.56:

“It is our understanding that commercially available AR15’s and M16’s – although some are stamped 5.56 Rem on the receiver – are manufactured with .223 chambers.”

So, even if your AR is stamped 5.56, is it really?  Check your owner’s manual or call the company directly and make sure you get an answer you feel comfortable with.

As if the confusion regarding the .223 vs 5.56 chambers wasn’t enough, there is a third possibility in the mix, that is being used by at least one major manufacturer.  The .223 Wylde chamber is a modified SAAMI-spec .223 chamber that allows for the safe use of 5.56 NATO rounds, but maintains tighter tolerances for better accuracy.

Yeah, yeah… What’s the bottom line?

Here’s the bottom line.  If you want to follow the safest possible course, always shoot .223 Remington ammunition.  The .223 Rem cartridge will safely shoot in any rifle chambered for the .223 or 5.56.

If you want to shoot 5.56 NATO rounds, make sure you have a rifle designed for the 5.56 military cartridge.  Shooting 5.56 in a normal .223 Rem rifle can result in bad things.

Sign Up
  • tinman61

    What about Rugers mini-14 I have shot russian rounds almost exclusiviely through mine, So far noprobelm.

  • kmunchie45

    There is no mention made of the Wylde chambering. Where does this fit?

  • R.Hall

    Just FYI…if you own a Bushmaster (I do) this is from the FAQ section of their website:
    “All Bushmaster rifles are chambered to accept 5.56mm ammunition and always have been. The NATO Spec 5.56mm chambers have a longer “leade” or throat than the SAAMI Spec .223 caliber chambers which have about half of the leade or throat of the 5.56mm chambering. While it is safe to fire both 5.56mm and .223 caliber ammunition in our rifles, the 5.56mm ammunition should not be fired in rifles chambered in .223 caliber as they will develop very high pressures.”

    Just wanted to share…


  • 5popeye5

    Yes the Wylde is mentioned………..Read slowly next time!

  • 5popeye5

    Yes there is……look again.

  • Duke_Digger

    Mini 14 marked .223 are really something between the two(almost equal to the wylde chamber). The only way one can ever determine exactly what their chamber is, is to make a chamber casting and measure it.
    One thing not covered, the reason for the longer “leade” and larger diameter in front of the neck is reliability in full auto conditions. Nato arms are actually ” assault weapons” and are designed for full auto operation.
    I always chamber my barrels to the “wilde” chamber. It’s the best for semi-auto operation and you can shoot both.

  • Duke_Digger

    As with any caliber/rifle, always check for signs of overpressure any time you change ammunition brands or projectile weight.(reloaders know this)

  • waljay

    What are the implications of the 5.56 round being fired in a bolt action rifle such
    as a Remington 700 chambered for .223?

  • waljay

    what would be the effect of firing the 5.56 round in a bolt action rifle chambered for the .223 (such as the Rem 700)?

  • Citizen Veteran

    Having had several AR15 rifles from Rock River, Colt and now a full house custom, I always made sure to have a Wylde chamber, over 5.56. There is a lot of cheap .223 ammo and surplus 5.56 for plinking. In my bolt .223, I only shoot commercial .223 Rem or reloads specific to .223. If you own a firearm, you should know it better than you know your wife. Ignorance and negligence are the enemy. So manufacturers are forced to issue warnings and bulletins for the stupid people.

    “It ain’t the gun son, it’s the guy behind it.” Learn your stuff! Less excuses and more work.

  • Guest

    This why I ordered custom reloading dies for my Bushmaster from Hornady and why I miked the leade and seat bullets .001″ off the leade.

    Mil-spec ammo chambers fine in the Bushmaster but not in my Ruger.

    Cases sized in standard reloading dies (off-the-shelf RCBS or Hornady) won’t chamber in my Bushmaster.

    I also carefully trim and polish all cases.

    I keep the bullets for my Bushmaster labeled and separate from my Ruger.

  • waynes99

    After reading the above article, I called Colt to find out if my AR15 can handle military ammo. I just got off the phone with some dumb broad at Colt, who doesn’t know anything about guns. She obviously is instructed to answer questions from a script. Apparently Colt doesn’t find it cost effective to hire knowledgeable people for their customer service. So if you want any answers, it is probably better to ask a local gunsmith.

  • DeltaDave

    What do you use to “mike the leade”? Is there a specific measuring device?

  • DeltaDave

    How do you “mike the leade”? Is there a specific measuring tool to accomplish that? Or am I overlooking a simpler way to do that?

  • don Khun

    thanks for the tips on the differancs between the 223/5.56 just purchased dpms mini sass .I immedeatly read the info it says it is chambered in 5.56 so far i have only fired 223s but i guess i am pretty safe
    thanks for the info

  • don Khun

    thanks for the tips on the 223/5.56 i just bought a dpms mini sass and immedeatly read the info on the weapon it says chambered in 5.56 guess i am safe{ i have only fired 223s out of it but that will change soon

  • airoverlord

    This is the usual military vs. civilian SNAFU that manufacturers and ammunition designers have gotten us into. Why the hell would two different cartridges be designed with near or perfectly identical outside dimensions? I don’t remember which round was designed first but, whoever did it first, that one should have been the way it was manufactured. I can imagine the military, liking the design, came into the picture tweeking this and changing that and now we have a possible dangerous situation knowing those “new” rounds would be eventually available to the public. Results: SNAFU! You military types know of that situation.

  • Guest

    Great article, thanks much! I was ‘aware’ of this issue due to purchase of a Kel-Tec .223 … but without the detailed explanation of case wall thickness, barrel throat length, rifling, and possible pressure problems on firing … again, a big thanks for such a clear explanation of this confusing issue! This is why I can’t wait for ‘Guns N Patriots’ to show up every week … I always learn new things like this and I LOVE it!

  • apache6

    With the exception of the Ruger mini-14 target rifle(chambered for 223)all Ruger mini-14′s are chambered for 5.56 !!!

  • apache6

    As do I,I read the same thing on their website !!!!

  • roadapple66

    I have an old “clinton-era” Bushmaster target rifle. The documents that came with the rifle, and the stampings on the side / barrel of the rifle, indicate .223, or 5.56 NATO. I have never had any problems with any of the ammo; new .223, or surplus 5.56. It did take some break-in when I got it new. It was very tight, and did not loosen-up until about a thousand rounds went through her. I do like the idea of the Wylde chambering. BTW, the Bushmaster has been extremely accurate with all of the ammunition I have tried; before, and after, break-in.

  • OIFVet06

    I think the problem developed back in the late 50s to early 60s. There were actually very similar rounds in the form of .222 and .224 varmint rounds used in bolt action rifles when the military started tinkering around with some of them, created a militarized .223 and developed it into the 5.56x45mm with a greater cross-sectional density than it’s civilian counterpart. Those were hectic and controversial times in firearms and bullet/cartridge development with wildcatters developing new lightweight rounds and the military changing its ordnance doctrine to accommodate a lighter bullet. Most of the problems were worked out but this one remains, though I don’t believe the problem is as bad as implied.

  • GrizzlyIX

    “Simplest solution. . .sell off the poodle shooters & move up to a MAN’S rifle,7.62 NATO, an FN/FAL, H-K 91, M1-A, et al.”

    The Late ‘Gunner’s Guru’ Jeff Cooper

  • sivles

    It’s all bullshit. Same as when the .308 and 7.62X51 NATO was cried about several years ago. Just a bunch of morons trying to let you know what they think they know….. whining and crying about everything. Show me just one AR15 that has committed suicide because of this crap!

  • Bill

    Not real sure, maybe someone can correct or verify…..
    I think I read that Kennedy and his Whiz kids ( who also caused problems W/ m-16) was in on some of these problems

  • Norm

    This has to be one of the dumbest articles ever written. The differences between .223 and 5.56 ammo are miniscule and inconsequential. Either ammo can easily and safely be fired in rifles chambered for either one. The most obviously false bit of info is the idea that 5.56 cases are thicker and have a smaller capacity than civvie .223. TOTALLY FALSE!! This was true with the .308 vs. 7.62 but not the .223 / 5.56. Totally wrong. This shows me that the author hasn’t done the most basic research, but is just repeating garbage.

    He’s jumping up & down, waving his arms hollering “Look at me! Look at me! I know something you don’t know! If you don’t do things my special way, YOU’RE ALL GONNA DIE!!!”


  • Chris H

    OR you can buy your semi in .30 caliber (as opposed to a varmint caliber.) That way you can eliminate the confusion AND not piss someone off so much that they want to kill you.

  • desertpooch

    If you are not sure, get a reloading die set and seat the bullets to a proper depth for the .223, then you won’t have any trouble with the throat. End of problem. Seating the 5.56 bullets to the .223 specs. shouldn’t be to difficult.

  • waynes99

    Norm, I agree with you 100%. I have been using military ammo exclusively in my AR15 for over 30 years, without any problems. I think Mr. Johnson, is just trying to get some publicity for his gun shop by regurgitating questionable data, designed to insight fear. Usually, this type of warning, is backed up by reports of the many injuries suffered by AR15 owners, who used the wrong ammo in their weapons. I did not see any information to indicate that ANYONE! has ever experienced any catastrophic failures. Perhaps, Guns and Patriots would better serve their readers if they required their so called experts to provide some facts and not just recycled opinions. What bothers me the most is that too many people will simply accept this crap as gospel, because it was published by Guns and Patriots.

  • MyronJPoltroonian

    Now I’m not a scientist, nor do I play one on TV. However, even I know there are simple ways to measure what you have. There is an alloy available to amateurs that enable you to make a casting of your rifles chamber which can then be measured for its dimensions – including leade. Further, there are inside dimension micrometers that (with careful use) will answer both case wall and web thickness questions. Plus, one can (and, I believe, should) use the simple water by volume and/or weight tests as well. Good quality tools too hard to use and expensive? Tells me a lot about how much you spend for good life insurance coverage. Don’t drop the payments.

  • one4gipper

    Very timely article. I have been thinking of a new rifle and narrowed it down to the 22-250 and the 223. If I had unlimited funds, clearly the 22-250 would be the caliber of choice. It shoots flatter, farther. However, being a .22 rimfire fan, I really appreciate cheap ammo. I can find .223 ammo for as little as $0.25 per round, while .22.250 averages up around $1.00 and much more for premium brands. I haven’t yet started loading my own.

    I notice that retailers use .223 and 5.56 almost interchangeably. For example, check out Able Ammo. It never occurred to be that there is any difference. Some really good deals seems to come from surplus 5.56 that is available in bulk. After reading your article, it appears that I need to do some additional research or just by reloading equipment and go for the .22-250.

  • Powderman

    Wayne, all Colt AR15 rifles–except the Match Target rifles–are chambered in 5.56×45 NATO.

  • waynes99

    Hi Powderman thanks, I appreciate the information. Why couldn’t Colt give this info to me? You would think that they would have access to all the specs on rifles that they produced. Maybe that dumb broad that I spoke with was just too lazy or too stupid to find it. Thanks again.

  • Powderman

    It’s inconsequential unless you cram the same load that you’re using for civilian .223 cases into military spec 5.56 cases. The cases ARE thicker, mostly because the ammunition might be used in either rifles, carbines or machine guns. It is prudent to reduce your starting loads about 10%, and watch carefully for any signs of pressure when loading.

    Another indication that military brass is different can be found when loading Federal .223 cases. For some reason, primer pockets loosen considerably when loading Federal brass in as little as two loadings. Now look at Lake City brass–it lasts considerably longer. I have some LC cases that are on their 6th reloading.

    So what’s the point?

    Lake City brass is made at the Lake City ammo depot/manufacturing plant–which is run by Alliant Techsystems (ATK)–which also makes Federal ammunition.

  • OIFVet06

    Indeed they were. Sudden changes in military doctrine envisioned a whole parade of technological changes and implementation that would never be allowed today. The concept of the “fast tumbling on impact bullet” simply did not fit enough combat scenarios to warrant its continued development. The concept worked “reasonably well” in Vietnam where most fighting environments were not the “brick and mortar” type encountered in Lebanon and Iraq. Add to that Vietnam saw fast engagements at very short to intermediate ranges where the 5.56x45mm excelled. The problem in Vietnam was not the bullet; it was the rifle and propellant. Both were changed incrementally over the years until the crowning development of the M-16A2 service rifle, a totally different and better design than the M-16/M-16A1. The early Vietnam-era rifles are no longer in service with the U.S. armed forces and the final remaining M-16A2s are being phased out in favor of the M-16A4, which I believe has pushed development of the M-16-series and the new heavier 5.56x45mm cartridge to their outer limits. The only technological improvement would be the HK proposal to replace all upper receivers and barrels with a new gas piston in place of the old gas impingement tube that could accommodate the new and superior 6.8mm cartridge. The proposal was rejected in 2007 as was HKs proposed 5.56x45mm M8 rifle. Remember too, any change in rifle and cartridge now would mean changing or converting hundreds of thousands of M-248 Squad Automatic Weapons and replacing billions of rounds of ammunition. Half a century ago, the “Whiz Kids” of the Kennedy administration bought into this thing and three generations of warriors have had to live with it and “make” it work to fit the ever changing dynamics of warfare. I know we strayed off of the subject of .223 Remington and 5.56x45mm NATO and its various bullet weights and required rifling twists, but civilian and military shooters alike have been caught up in that four decades old fiasco.

  • Guest

    Those signs are never consistent or reliable: dimpled primers, difficult extraction, shiny case heads, etc., are not to be completely trusted.

    The only way to really know is with pressure-detecting equipment.

  • PNWJaeger

    What about the Golani Galil Sporter by Century Arms?

    I own one. It’s a .223 Rem, though I had read that 5.56 Nato could be fired thru it. In 2009 (when I acquired it) I contacted Century Arms about this & a couple other questions. On the subject of .223 vs 5.56, the Century Arms rep wrote:

    “I don’t have much direct information concerning the chambering, but we do use 5.56mm ammunition for testing and have had no problems. The bore twist was chosen to allow for the use of both cartridges with reasonable accuracy.”

    I have not (yet) fired 5.56 Nato thru it, and at this point I’m undecided if I will or not.

  • gwam

    sivles. Sir – Recommend you check out:

  • gwam

    Armalite AR15A4: Caliber: .223/5.56 X 45 mm NATO




    If your M-15™ Series firearm is chambered for 5.56 cartridges, it will fire all standardized U.S. military 5.56mm cartridges and all factory loaded cartridges in .223 Remington caliber. Do not attempt to fire any other cartridges in this firearm.


  • 1annoman2

    total BS if you want something to worry about think about this. The barrel is chrome lined and so is the chamber. Chrome wont stand up to the punishment of the firing so in the first month of use the chrome is burned off now what? It is simple clean the gun and when the barrel is trashed put a new one on its is not like this weapon system is not modular. And for the record I am a custom gun maker and I have been converting barrels marked 223 to .223 /5.56 for years and have not had a single problem. the issue is the chamber size needs to
    be adjusted slightly to run the 5.56 reliably, they run great with 5.56
    they run sweet with a slight reaming. The chrome is burned out of barrel rather fast so reaming the chamber is not an issue and the chrome was added when the guns failed to run reliably in S.E.A. in 1965 that was corrected by chrome lining the barrel and adding a cleaning kit–no shit DOD and all they need is wiped out after use!! If you are also new to the AR /m16 game remember a bolt carrier and bolt are best treated like a pu**y. It will serve you better if you use it very wet. Quality barrels will shot both types of ammo just fine. If you want to bitch bitch about morons that run Wolf in their hot AR. Keep it up I make a fortune taking live rounds out always a wolf round. Just look at your damn barrel most AR barrels are cut .223-5.56. If you are still not satisfied please feel free to ship your UNLOADED, no stuck rounds, upper receiver only I do hold a valid type 7 FFL manufacturer so all BATF regulations will apply. I will be happy to modify the chamber size for you at minimal cost. I am in business to make money but let me say this my USMC grandfather, family tradition to serve, a fool and his money are soon parted. So worry about something else like when the middle east is going to tatally fall apart and them by god you will need that Fu***ng AR to work!

  • 1annoman2

    This is crazy there are better things to worry about if the rifle is not running correctly send it to me unloaded and I will ream the chamber and thought. This is a standard gun smithing procedure and is cheap you will spend more on shipping than I will charge to fix a non problem. If the gun runs with 5.56 it is fine if it won’t it needs reamed, a procedure done to all military rifles made before 1968 and all guns donated to law enforcement from the military. If your worried about the chrome chamber, don’t if you have fired more than a 100 rounds it is gone 2 inches up the barrel.

  • Ravenmaster1

    Waynes99 –Why couldn’t Colt give you a straight answer?
    That’s easy- LAWYERS!
    You can’t get accurate information or a straight answer to ANYTHING today, because the lawyers have told everyone NOT to answer technical questions ! Plus – as you mention – everyone is hiring nitwits at $7.00/hr rather than intelligent people with working brains.

  • Jack_4ral

    All M-16, AR-15 rifles are chambered in .223 Remington.
    Remington has the patent on this round, even my Russian made rounds say .223 REM (5.56X45), my Windchester rounds say .223 Rem..
    Look out for reloads, you can identify these factory reloads by the discoloration around the shoulder of the neck, they are heated before resizing.
    I bought some in bulk bags, some had hairline cracks around the rims, some had buldged primers and all were not fully resized, when reloading this brass, even the port for the primer was offset just enough to deform the primers.
    These could be used safely in bolt action or break down rifles, but are very dangerous in simi-auto or auto cycling rifles.
    The military uses the metric system, that is where you get 5.56X45 MM (.223 Cal.), 7.62X51 (.308 Cal.), 105 MM Howitzer, 81 MM mortar and all maps graduated in meters, not yards. The only yard I seen in the Army was being cut with a lawn mover.
    I did see an 8 inch gun, big sucker, I do not know why it was designated 8 inch, I guess that when it gets that big it is measured in inches, as in Navel guns.
    When reloading .223 Cal. (5.56X45 MM) brass, make sure your die will resize the full lenght of the brass.
    Be careful, guns kill.

  • bigtedhead

    A simple check one can do is (all safties in mind) to slowly close the action on a round. If you notice any odd resistance the case body might be to long or the bullet could be sticking out too far. IE 5.56 in a .223 chamber. If the bullet is out too far you’ll likely see scuff marks all around its ogive from the rifling groves.

  • Davidmcleod30

    I have read my fair share of BS in 20 years of military service, butn you take the cake.  I worked on weapons at all levels except Derpot and after reading your article,I can safely say I would NOT let you touch asnthing I ahve that shoots, because I can tell you have NO knowledge about the M16 system(Stoner system) or the reason why the bolts and chambers were chromed during the War the NEA.  You need to read some history, I suggest you check out the US Army Ordnance Center and School Museum.  They can give you some really some lessons on the M16 or AR15 that civilians use today.  Hell, you may not be able to read for all I know, but before you try something out that is going to misdirection some poor person that knows very little about this type of weapon, you miht want to think of your good name.

  • Joseph Damiani

    there’s also a documentary on the History Channel about the history of the M-16 and it’s variants. I’d lose to try the Beowolf one day

  • har82

    Grizz, most of those are not nearly as accurate as a 223. Besides, so long as my mini continues to put beautiful little – clean holes – in 1/4″ steel plates I am just tickled :) , And I have shot hundreds of that cheap chinese 5.56 ammo in it. Nary a problem one.

    I must say though, I would love one of those FAL’s lol.

  • har82

    Say, all you guys. Something that has puzzled me for years . My mini , no matter what brand of cartridge I use will have a flyer out of 5 rounds fired. 3 will touch, 1 about 1/4″ out , and the 5th will always be around 1, to 1-1/2″ out. I’ve loaded my own for years , and even used several different brands. But it seems it is always the same. D a m n strange ,, if you ask me. And that is on a rest so it’s not just me lol.

  • BigUgly666

    Are you insane?

  • BigUgly666

    So – the throat may be different in rifles made for different purpose, but the loading specs both have the same Cartridge Overall Length, right?

  • Manuel Yates

    Story is a bunch of bull! Many, many, many 5.56mm and .223 fired through many different rifles and no problems what so ever.

  • Concerned4America

    If you see the signs, take heed. Yes, you may have an overpressure with no obvious sign but low or normal pressure loads rarely dimple primers etc.

  • StackoLee

    Anyone who owns an AR-15 and DOESN’T know this utterly fundamental difference must be an ignoramus who probably doesn’t know a whole lot of other fundamental information about their own weapons.

    This stuff is rudimentary…

  • ken wat

    thanks that what i wanted to no

  • John Whittington

    I have heard the same crap about firing .223 in a AK47 which by the way is a .225 and was designed so that they could fire M16 rounds in thier AK47 rifles yet the opposite is not true. Also an M16 clip can be placed in an AK47 rifle. I know a Viet Nam Vet who put M16 bullets & AK47 bullets in an M16 clip and fired the whole bunch in an AK47 rifle!

  • John Whittington

    I think they are telling this crap so we don’t use their ammo when they come trying to take over this country!

  • Valannin

    Not one word of what you said is factually correct. Every single possible mathematical dimension of both the ammunition and their respective magazines for those two rifle systems are completely different.

  • accsport

    I’ve shot Mini-14′s for many years and the 1/7 twist barrels will very nicely stabilize the larger (up to 77gr) bullets for premium accuracy. And the Mini has a .162 throat which is the NATO spec for the longer ammunition.

  • BeGe1

    What knowledgeable gun expert that you know of would take a job sitting around all day at a desk answering phone questions? I know none in my experience. :P

  • Mark Hatzi

    that’s odd. the M 14 was one of the world most accurate battle rifles, under the FNLAR, the 308/7.62 is an awesome cartridge, capable of 1000 yd shots with enough energy down range to be plenty reliable, the 223/5.56 now with the 62 gr bullet has far superior energy over the old 55 gr and is a nice pleasant rifle to fire man or woman,but after 500 yds, i still prefer the 08, the weight of the rifles and ammunition is the big factor.

  • Mark Hatzi

    thanks I’ll keep both, LOL so would Jeff if he were alive today

  • har82

    Well I never said I didn’t like ,,, the 308. But let’s face it , not many soldiers are going to be shooting – anyone – 1500 feet down range ( 500 yards , 5 ,, football fields ) lol. Most combat here will be fairly close range , and I am quite sure ,, I can pick off someone clean down the end of the street with mine . :) And as you yourself state , I can carry a lot more 223′s , than I can 308′s . But I do like them . :)

  • Ronald Reed

    That would depend on pay!

  • Ronald Reed

    Timmy mcvieh was a member of the “patriots”…

  • westoast

    There is another situation where pressures above normal can occur. Hand loading.
    A hand loading manual will tell you to lower your powder charge for military cases (all military calibers) and work back up to the load you want checking for signs of high pressures along the way.
    Hand loading is a great past time.

  • chris drach

    just get an AK and don’t sweat a thing. in a SHTF situation you’ll be glad to have a proven battle rifle that keeps a lickin’ and keeps on tickin’

  • Carson Goddard

    I use 5.56 nato ammo in my ruger mini 14 and never had a problem… This much ado about the banning rather than a real danger.. I have read more posts since the move to ban these so called assault rifles than was ever printed copies of any ammo manufactures or weapons manufactures. It seems that the scare factories are up and running.. But I will take my bolt action .243 for accuracy over the .223 or the 5.56 nato. It is a 6mm cartridge with a necked down nato 7.62 cartridge with all of the balls needed to reach out to over 300 yrds accurately

  • kounjd

    Hello, these Chinese information may be useful to you











    李长江两口子和女儿李晓晔的邪教组织股东上海市委书记韩正诱奸After School



























































    Li Changjiang couple and girl Li Xiaoye destroying the company stock

    market manipulation, the couple and Li Changjiang girl Li Xiaoye

    destroying the company flickers people to buy stocks, futures, they

    heavily short money, but in other markets have short several million

    contract, each number is not necessarily







    具 RptGet 2009版这些系统的客户机或服务器,然后入侵到上海证券交易所服务


    Invasion of the Shanghai Stock Exchange servers, in which Li

    Changjiang the couple and Li Xiao Ye both girls destroying the company

    secrets,using hacking the wisdom to do what you want to do



    Shanghai stock exchange server data has been a lot of people steal, Li

    Changjiang couple and girl Li Xiaoye destroying the company pulled the

    stock market is to stabilize the shareholders, A shares will continue

    to decline

    Hello, Li Changjiang, the couple have a harmful companies。Business

    throughout the country, including some abroad, specializing in harmful

    work.Specializing in harm.Li Changjiang, the couple sent follow-up

    survey each other.Intimidation, aggressive behavior, seriously affect

    the social order.Li Changjiang, couples home in the West Award Street

    Shenyang Liaoning China .Li Changjiang, the couple tried to cover up

    their harmful behavior.And the various scandals of the girl, Li Xiao

    Ye, divorced.Li Changjiang,the couple and Li Xiao Ye photos.






















    晔的邪教组织还在网上毁人,传播各种真的或PS过的图片视频造谣生事。 李长















































































































  • Independentrd

    I gave up a very good paying job because of boredom. Even good pay will only work for some.

  • John Fah-q Smith

    Better yet, move to the AR-10, or drop-in a .50 BeoWulf upper on you current AR lower.
    Do THAT with an AK… :)

  • John Caile

    Uhhh, folks, “energy” is far less relevant than WHAT THE BULLET does. A tiny 62 grain 5.56 round at 2800 – 3000 fps (out of a typical 16″ carbine barrel) cranks out around 1200 ft.lbs. of energy at the muzzle. A 255 grain 45 Long Colt has “only” 400 ft. lbs. of energy. Now, if you only had one shot, which bullet is likely to do the most damage to, say, an 800 lb. Brown Bear…or a meth-stoked 250 lb. psychotic man? (The reason a 250 grain .338 hunting load is so devastating is the it has BOTH a lot of velocity AND a big, heavy bullet that mushrooms to a huge diameter – ergo, a massive wound channel).

    Oh, and yes, the easy answer to the 223/5.56 is as the author says: 223 in anything, but 5.56 ONLY in military spec 5.56 guns.

  • Michael Taylor

    Does this hold true for bolt action .223 ?

  • Phillep Harding

    Reloaders have a problem, using .223 loads in a 5.55.

  • rickcain2320

    Relax, none of you will ever be in SHTF.

  • MRandolph_Kruger

    He weighs 800 lbs?

  • MRandolph_Kruger

    Exactly, you buy ammo from an ammo manufacturer. Guns dont blow up, ammo does. Like my momma mixing 16 ga. shells with 12 ga. shells when we were hunting dove.

    Only took two shells for the noise to get so loud that she asked me to take a look. Blown brass band at the base kind of gave it away.

  • Emkay

    and its the same thing the article says…duh…

  • Emkay

    good rifles, those will get the ‘hoplophobics going….

  • Emkay

    think ‘division’, .223 will go into 5.56
    but 5.56 will not go into .223…..even easier…

  • David L Campbell Jr.

    If you own a Colt AR-15 it may say .223 REM, but it is chambered for the 5.56mm. I was in the military and sometimes came across some loose rounds in my gear, and I shot it out of my personal AR. When I contacted Colt they stated it is indeed chambered for the 5.56mm, the .223 is stamped for easy identification between Colt AR’s and military Colt M16′s/M4′s, as well as .223 is generally cheaper to purchase.

  • David L Campbell Jr.

    I believe you just had a bad experience (because it was a woman you were speaking with). The male (husky female??) I talked to answered my question almost without hesitation once he/she knew what model of AR-15 I had. Just scroll up to see what I was told

  • David L Campbell Jr.

    Vast majority of AR’s are chambered for 5.56. Besides, the difference is in the rifles, not the ammo. the differences between the ammo is inconsequential, but the way the chambered is manufactured and the rifling is done actually matters.

  • paul

    Are you republican, Yeah, I thought so.

  • Bob G

    M1 Garand and 1911 Colt. You can’t go wrong.

  • nonPCrealist

    Yes, any rifle chambered for .223 vs 5.56. The type of action doesn’t matter.

  • Pth

    Naw, just the opposite. They want you to save you ammo for when you really need it. At least I ain’t wasting my couple a rounds.

  • flyin4awa

    I’ve spoken with Ruger about the Mini-14, and they have assured me that it is chambered for the 5.56.

  • Kriegar

    Actually, what it IS saying is that with the Bushmaster you have no worries…duh…

  • ol’ vet

    The 7.62X51 NATO round is different than the .308 that is manufactured and sold in Amerika, and probably the same situation as the 5.56 and the .223. I prefer to shoot the 7.62X51, but in a pinch I will use the .308 understanding there is a million to one chance of some calamady.
    Most folks say there is really no difference and you can shoot either in the AR-15 and the M1A, but as far as I know there hasn’t been a failure as described in this article reported. Use your best judgement, and your life can depend on what you decide under the forseeable circumstances. But I know if the weapons we buy have the problem, the weapons the ferals purchase has the same.

  • glock 19 fan

    McVeigh also attended a meeting of the Michigan Militia but was kicked out because of his extremist remarks. No matter; the lamestream media just wanted to say that he had been there and use the “guilt by association” ploy to demonize the whole group.

  • glock 19 fan

    But….but….but….I have a .30-06.

  • sneaky pete

    Probably a almost worthless topic. Ive shot for decades 223 and 5.56 in the same guns over and over again with never a problem.Only one gun i have ever owned had a problem a AR 15 with a FN barrel..JUNK.If you are a hand loader you can seat your own bullet depth.The M 14 /M1 A1 is without a doubt the finest battle rifle ever built.The rifle is capable of holding sub min angle out of the box with a blind shooter.MOST of the expensive FALs i have seen wont even get that with a scope..Neither will any HK G3s.
    Most all 223 308 and 30 06 have the same velocity of around 3000 ft per second.Everyone of these rounds will have about the same bullet drop also of around 2 ft of drop at 400 yards..and 4 to 5 ft of drop at 500 yards.Ive got a Ruger all weather stainless 77 in 223.Ive never fired anything out of it that was not VERY accurate.

  • sneaky pete

    If you have a over loaded charge or a under loaded charge you will know it IMMEDIATELY ..from the sound

  • brian

    look at the barrel…if it says 5.56 then you are good to go…receiver means nothing

  • brian

    he is talking about the ruger mini 14 that is only accurate if you own one…if u used to own one then u know the pencil thin barrel heats up and slings lead in 8 inch groups at 100 yards…not to be confused with the venerable m14

  • brian

    dont take gun advice from a news story….next story…most barrels on an ar 15 are not chambered for just 223….

  • Mark Hatzi

    really I think the 45, I want penetration without an exit as the 556 would do, the 45 was built for that very thing…

  • Mark Hatzi

    LOL it does get hot doesn’t it.. but I guess I am lucky, even after 3 / 20 round clips still inside 3 inches

  • Mark Hatzi

    no he’s not, carry 2 rounds for every 1 of 7.62 ( 308) and unless any fighting goes rural, it will be house to house, the worst kind and dirtiest there is

  • Mark Hatzi

    LOL ok the 06 or 30 Springfield as it was known earlier, FANTASTIC round, and the parent of so many others, the 25-06/243-270/ ect.. We had 3 M1 Garands in 06. I loved these rifles, were awesome but weighed almost 12# each and only carried 8 rounds

  • Mark Hatzi

    SMALL BASE DIES, read the box,

  • Mark Hatzi

    LOL I still am reloading 06 and 7.62 L C brass, some has to be reloaded 10 times and is 50+ yrs old

  • mrhuehls

    In terms combat with long guns a 30 cal round will go through a lot more than a 22 cal round, using approximate dimensions for clarity. You can carry more rounds of the lighter ammo, but the penetrating power of 30 cal means the opposing force has a more limited choice of places for actual cover, and I did tend to estimate their positions behind concealment and shoot through it. I’ve never really been a quantity over quality gunman, but I do believe my opinion has merit.

  • Smiddywesson

    That was then, this is now. The 580 series has a redesigned barrel that doesn’t wander as it heats. The new version is a good compromise between an AR and an AK. I agree, the old ranch rifles were inferior.

  • Smiddywesson

    I don’t value the mini for it’s accuracy, but the new ones are plenty accurate, it’s the weight/ruggedness ratio. It shoots dirty, wet and icy, and it will take a beating because it’s all steel, and yet, it doesn’t weigh all that much.

  • Smiddywesson

    Possible isn’t probable. There are literally MILLIONS of these guns out there and no reports of gun failures. I would prefer the proper ammo, but in a pinch I’d use what I have because It’s more likely I shoot myself in the foot than the gun will fail.

  • NordopiaHills

    The .243 is based on the .308-it’s a.308 case necked down to accept the .243 bullet.
    The .270 is based on the ’06.
    30-06 and .308 are very different-the ’06 is long action, the ’08 is short-action.

  • trigger46

    I think most deaths resulting from gun accidents have nothing to do with the size of the leade, partners…

  • gfr

    AR15 cartridge is 5.56 x 45, AK47 Cartridge is 7.62 x 39 – wouldn’t fit..
    Perhaps you meant the AK74 cartridge which is 5.45 x 39?

  • EdWalton

    Have a competent gunsmith check the leade.
    It can be reamed if needed.

  • Nobody Special

    Just bought a Bushmaster…I can use both :o)

  • Kriegar


  • Railcar79

    wow, talk about bad advice. AK47 is 7.62×39, AR/M16 is a 5.56×45. AR ammo is 6 mm too long, and nowhere near big enough to fit. even attmpting to chamber the wrong round is beyond foolish. top it off, the magazines are different shape, size, locking lugs, everything is different.

  • grunion

    On a DPMS Sportical I saw, it was stamped .223/5.56mm on the receiver. I am guessing it might be sloppy in there or is it a reasonable configuration?


    @Krieger: R. Hall was just supplying a second source that proves up the data. Therefore, don’t be stupid.


    I fired Expert in 1962 with a WW2 M1 Garand out to 600 yards in basic training. It was deadly even though the bore was really worn. True, it was not necessary in “house to house” use but I was certain that if I could see it, I could hit it hard.
    In a separate matter for other writers, unless you are writing about said battle rifle, don’t use the term “clip”. It makes you sound like a mope.


    Norm: have you ever used the “water capacity” test? If no, please go away.

  • Kriegar

    Clearly, it was not I who was being “stupid”, my good soul. If you take just a moment, you will see that I was replying to this:

    Emkay apache6 • 10 months ago

    and its the same thing the article says…duh…

  • Kriegar

    Again, obviously, I was replying to this post:

    Emkay apache6 • 10 months ago

    and its the same thing the article says…duh…

    Therefore, I beseech you, that you not be stupid. Lord, you conservatives have to censor everything, and argue with everyone who agrees with you. Just stop it.

  • Kriegar

    Uh, dude…7.62 mm does not make a .223

  • Randy

    I have a Colt HBar Match AR 15 and it is stamped 223 on the receiver, yet the barrel is stamped 5.56. Is it safe to shoot either round or should I stay with the 223?

  • Powderman

    Yes. You can safely shoot 5.56 ammunition in this rifle.

  • M40

    The barrel stamp is ALWAYS the best indicator. Remember, you can swap out barrels, so therefore, the receiver stamp is really not what you want to go by!

  • Scott Roberts

    Sounds like a good idea would be to get a gunsmith to check the leade on your rifle- and if possible(not sure- not a gunsmith), modify it to the .556 NATO standard- unless you choose to use only .223…

  • Scott Roberts

    Here’s a toss into the fire.. I’ll stick with 30.06… the little calibers are nice(used them as a Cav Scout in the army) but I like the power and distance… Just personal preference…

  • Scott Roberts

    Tell that to the Marines from WWII… And Korea…

  • Scott Roberts

    I’d rather take them out at long range… The closer you let them get, the faster you gotta reload!

  • Scott Roberts

    I was about to raise a hand about the term “clip” as regards the Garand- but I reread, and see you made the right point… lol… hand dropped… Who the hell came up with the term “en-bloc” anyway?


    The average income shooter only needs a good quality micrometer to measure expansion just above the “belt” area. (It’s called that even though that brass has no actual belt.


    @Norm the simple way to verify capacity of brass in any caliber is he water test. This was a must in the days of wildcats.


    The classic problem was US Cartridge 30 cal M2. for the M1 Garand. compared to the commercial 3006 cartridge. The M2 was loaded to much lower SAAMI specs. about 8,000 less PSI.


    A chamber cast is the exact way to resolve the issue.


    The issue is the amount of ammo that a trooper can carry on patrol. Many soldiers/Marines are not great shots. Moreover, with select fire, a lot of ammo is wasted in a firefight. Even though 5.56 round is just a little better that swinging a pool cue, the trooper will have more of it.


    You exaggerate!


    @Myron. The important issue of case capacity causing pressure problems was controlled by the water test. Wildcat reloaders used it all the time to sort brass. All that is needed is a reloaders’ scale. I did it all the time about 50 years ago.


    En bloc system means that the cartridges are held together by either a “stripper” clip like used for a 1903 Springfield or a “clip” used in a M1 Garand. the rounds are inserted in mass into the magazine that is a permanent part of the weapon. Note that while the Garand clip actually goes into the magazine and is subsequently ejected we empty, the stripper just aligns in a “slot” above the Springfield’s magazine. the loader just pushes down on the rounds causing the rounds into the permanent “en bloc” magazine.

  • Clancy Young

    What in the world does that have to do with safely operating a firearm.Paul if you don’t like guns or care about weapon safety comment somewhere else please.

  • Clancy Young

    That’s interesting Ruger says any ammo not made to American spec’s AKA steel casings will void the warranty and wear out the extractor on my Mini 14. The cheap Chinese ammo is a lot less expensive and I’ve been tempted to buy some.

  • Clancy Young

    Just bought a brand new Mini 14 don’t think they have those issues now 2 inch groups at 100 yards at the range this weekend.A rifle that has been produced for as long as the Mini has is doing something right..

  • Clancy Young

    Guess Colt has outsourced their customer service to India or Pakistan like every other major company in the US.

  • Fred Derf


  • You can call me Siggy

    And the more likely they are to shoot you.

  • Mark Hatzi

    LOL that is when hey are both handy, he M14 at 1000 yds, the AR at 500….

  • Mark Hatzi

    shoot twice

  • Mark Hatzi

    LOL what, and they are “ALL” BASED on the same case, the original 30 Springfield or 06, sorry, you have some checking to do
    Hell, so was the 44 auto mag, ou could se ANY of those cases and make it