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5.56 in a .223 problems?
spudshot
Member Posts: 136 ✭✭✭
i'm looking at buying a remington 700, in either .223 or .308, i've been reading around and i've found that according to SAAMI it is unsafe to fire 5.56mm mil-surp ammo in .223 rifles due to a difference in chamber pressure. is this old information? it seems like rifle manufacturers would properly treat their rifles to handle the increased pressure. i'm just wondering if it would be alright to fire 5.56mm in a bolt action .223 if i would buy it in that caliber. if not i'll just go with the .308.
Comments
A rifle chambered for 5.56 will handle .223 but vice-versa you may have problems. I know that both the AR-15 and Mini-14 will handle the 5.56, and their owner's manual specifies that military ammunition may be used.
Perhaps you should write to Remington or ask your FFL to let you read the manual before you buy the rifle.
"5.56 mm NATO vs. .223 Remington
In January 1979, the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI) advised that 5.56 x 45 mm military specification ammunition is generally not safe to fire in .223 Remington-chambered rifles (which are mainly civilian sporting rifles). [1] The chambers of weapons intended to take the NATO round are oversize relative to the civilian weapons to allow for greater variation in production (and hence reliability), and 'hotter' loads containing more propellant. By contrast, SAAMI-specification chambers are manufactured tighter (for accuracy), and 5.56 mm NATO ammunition, at the larger end of the manufacturers' tolerances, will be too tight and result in overpressure. This can cause excessive wear, or even theoretically cause parts of the rifle to rupture. Conversely, civilian .223 ammunition is perfectly safe to use in military rifles.[2]
"
Does that mean that a match chamber in a AR should not fire 5.56 and only .223?
The chambers of weapons intended to take the NATO round are oversize relative to the civilian weapons to allow for greater variation in production quote:
Does that mean that a match chamber in a AR should not fire 5.56 and only .223?
No,actually!
**** paraphrase from bushmaster catalog ****
For example in a bushmaster chambered both in 5.56, and 223 is that the 'leade' or 'throat' in machined back further (length of chamber is longer) to allow the higher pressures of the 5.56 round. If you use 223 ammo in that bushmaster designed for both rounds you will get a slight drop in pressure. Most people will not even notice this, but all bushmaster rifles are made this way.
Clouder..
I have personally witnessed problems, and each time it was when 5.56 ammo was used in a BOLT action rifle chambered for 223 Remington. Autos and semiautos soak up some of the pressure when operating the action and usually have looser tolerances than a bolt or lever action.
The 5.56 NATO stuff is made in plants all over the world and can have wide variances in pressures and consistancies in brass length and powder charges. Some of these plants probably have kids who just graduated from the shoe factory to running the loading press and powder measures at the ammo factory. -- Think about it.
I've seen 5.56 ammo that cycled just fine thru a mini-14 blow the primers out when put in a Ruger M77 MKII bolt action 223 Rem., and also saw the bolt face of a Remington 700 223 Rem. embedded with brass and the extractor broken when using 5.56 ammo that worked just fine in an AR15.
It really just depends on how the chamber and throat(or leade) is cut/sized in the particular gun.
Ammo that is loaded to acceptable pressure in a 5.56 chamber may create excessive pressure when used in a 223 Rem. chambered gun if the brass is jammed in tight.
Food for thought..........[:0]
I have personally never had a problem shooting 5.56 in my brothers remington .223, the only thing I have noticed is that the groups opened up from .65 to .90 (w/ china sports 55gr.), its a good cheep way to teach someone how to shoot a good gun or to just do some plinking, there has been much talk about nothing when it comes to the different pressures, after all the same remington action that can handle the ultra mags is also used for the .223, so what do you think is stronger, a AR or a M-700?
Any size cartridge can be loaded to high pressure. It doesn't have to be a large cartridge like an Ultra-Mag to have dangerously high pressure, including a 223. And for what it's worth, the Ultra-Mags are only loaded to SAAMI Pressure specs with factory ammo...[:0]
What a crock. Shot either or, mix and match. Same with the 7.62 NATO and a 308 Winchester, or surplus '06 and factory stuff.
Clouder..
Just because you haven't personally had problems doesn't mean the potential isn't there. I went for years doing the same thing until I got the wrong batches of ammo in the right guns and saw it for myself...[:0]
The only reason why I will buy an AR15 is so I have a lightweight, low recoil rifle to teach people how to fire a rifle. After they can fire that successfully, I'll upgrade them to my M1A, and then to my Savage 111C .30-06 bolt-action...(and laugh at the bruise they'll get after 10 rounds! [:D][}:)])
Then hand them my 450 marlin guide gun and watch them run![:D] Nasty beast that it is!
He was holding his shoulder with his non firing hand, and holding my shotgun with his firing hand. It damn near knocked him off his feet. My dad refrained from shooting.
My brother's only comment after shooting my Nova with a 3 1/2" turkey shell was, "Why...?"
He was holding his shoulder with his non firing hand, and holding my shotgun with his firing hand. It damn near knocked him off his feet. My dad refrained from shooting.
LMAO. I went turkey hunting this spring with my new Mossy 835, chambered to hold a 3.5" shell. I was in a kneeling position, and when I pulled the trigger I was promptly knocked on my @$$. I missed the bird but was laughing so hard that it didn't matter. I just wasn't expecting that much recoil. it was the first time I'd ever fired a 3.5" shell.
...(and laugh at the bruise they'll get after 10 rounds! )
I can do the same with my m-44, 7.62x54r with the steel butt plate on it.
I take it out and put 50 or so rounds through it and my shoulder gets brused for a couple days, and I'm used to shooting it.
I have a Benelli Super Black Eagle, 3?" semiauto shotgun with magazine-extencion so it holds six 3?" shells and seven shells in 3" or shorter.
I have no problem fully loading the gun with full/max-dram huntingloads - and shooting it empty rapidly.
It's just plain fun.
Also plinking sodacans with 1 5/8 Oz full huntingloads is as fun as it gets.
Ok ok, I've got a low centre of gravity with my 5' 6" and 275lbs.. and can handle recoil like bigger boys. =o)
There is a difference, no matter how small some like to make it seem. But 10,000 PSI is no small difference to me and when some folks finally get the full impact of this difference, they will change their tune. Until then, they will stridently claim that the rest of us are worrying about nothing and that they truly know better. So be it.
One of the current improvements is in chamber designs. There are about 8 different chamber designs available to the public when someone requests a custom chamber. These newer chamber designs minimize the pressure/length differences between 5.56 NATO and the .223 Rem.
Here is a synopsis of some responses from accepted Experts in our industry:
http://www.thegunzone.com/556v223.html
With the appearance of full metal jacket military 5.56 ammunition on the commercial Market, it has come to the attention of the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI) that the use of military 5.56mm ammunition in sporting rifles chambered for Caliber .223 Remington cartridges can lead to higher-than-normal chamber pressures and possible hazards for the firearm, its user and bystanders.
Tests have confirmed that chamber pressures in a sporting rifle may be significantly higher in the same gun when using military 5.56mm ammunition rather than commercially loaded Caliber .223 Remington cartridges, according to SAAMI.
SAAMI points out that chambers for military rifles have a different throat configuration than chambers for sporting firearms which, together with the full metal jacket of the military projectile, may account for the higher pressures which result when military ammunition is fired in a sporting chamber.
SAAMI recommends that a firearm be fired only with the cartridge for which it is specifically chambered by the manufacturer.
http://www.armalite.com/library/techNotes/tnote45.htm
FACTS:
.223 Remington (SAAMI standard) and 5.56mm (NATO standard) rifle chambers are almost identical. The difference is largely limited to the "freebore," the cylindrical space in front of the case mouth, and the "lead" or "leade," the the tapered region that eases the bullet into full engagement with the rifling. NATO and SAAMI cartridges can normally be used interchangeably with no problem.
The SAAMI chamber features less freebore and a tighter leade, which normally provide better bullet fit and match-grade accuracy than the NATO chamber. It is wonderfully suited to match bullets.
Millions of rounds of NATO ammunition have been fired safely in Eagle Arms' and ArmaLite's SAAMI chambers over the past 15 years. 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 or powder stains that reveal gasses leaking around the primer.
The first few rounds of ALL ammunition, from whatever source or lot, should be checked for pressure and other signs of defect before firing large quantities. If you have a problem, you can generally bet that the ammunition meets neither SAAMI nor NATO specifications.
ArmaLite has adopted a practice of using a special, modified SAAMI chambers in its stainless steel match barrels. This chamber is better for match use than the NATO chamber, but fires the NATO ammunition perfectly. We use the NATO chamber in all moly (phosphated) and chrome-lined barrels.
ArmaLite's larger AR-10r rifles are all chambered with 7.62mm NATO chambers. .308 Winchester (SAAMI standard) ammunition functions perfectly in the 7.62mm chambers.
http://www.fulton-armory.com/556-vs-223-Chambers.htm
If we are talking about .223 Remington SAAMI-spec chambers in an AR15, OH NO!
Do NOT use such a chambering if you EVER plan on shooting any military NATO 5.56 ammo, which happens to be only the most common, least expensive and most widely used AR15 cartridge available in all the world. In other words, NEVER buy/use a SAAMI-spec chamber in a battle rifle, especially if the barrel and chamber are chromed, as you cannot fix it!
Here's the problem. Many NATO cartridges have bullets that will become jammed into the rifling of a SAAMI chambering (the throat is too short). This is VERY DANGEROUS, for a grat number of reasons.
Fulton Armory uses a "5.56 Match" chambering in its rifles/uppers/barrels (in fact our barrels are marked as such), which is a slightly modified SAAMI chamber with a tad longer throat to accommodate NATO bullets. The Fulton Armory 5.56 Match chamber allows for the safe and reliable use of all SAAMI and NATO ammo, while offering the accuracy potential of the SAAMI chamberings with match commercial cartridges. Remember, there's often a large difference between bolt guns and military rifles. This particularly true for the 5.56 vs .223; Fulton Armory is well known for the finest performance for any given platform, and our 5.56 Match chamber is one way we achieve that performance with the AR-15-type rifle.
Hope this helps.
Best regards,
Clint McKee
http://www.winchester.com/lawenforcement/news/newsview.aspx?storyid=11
News and Press Releases
.223 Rem VS 5.56mm
Paul Nowak
5/4/2001
.223 Rem VS 5.56mm
There are a lot of questions about these two cartridges. Many people think they are identical - merely different designations for commercial and military. The truth is that, although somewhat similar, they are not the same and you should know the differences before buying either cartridge.
* The cartridge casings for both calibers have basically the same length and exterior dimensions.
* The 5.56 round, loaded to Military Specification, typically has higher velocity and chamber pressure than the .223 Rem.
* The 5.56 cartridge case may have thicker walls, and a thicker head, for extra strength. This better contains the higher chamber pressure. However, a thicker case reduces powder capacity, which is of concern to the reloader.
* The 5.56mm and .223 Rem chambers are nearly identical. The difference is in the "Leade". Leade is defined as the portion of the barrel directly in front of the chamber where the rifling has been conically removed to allow room for the seated bullet. It is also more commonly known as the throat. Leade in a .223 Rem chamber is usually .085". In a 5.56mm chamber the leade is typically .162", or almost twice as much as in the 223 Rem chamber.
* You can fire .223 Rem cartridges in 5.56mm chambers with this longer leade, but you will generally have a slight loss in accuracy and velocity over firing the .223 round in the chamber with the shorter leade it was designed for.
* Problems may occur when firing the higher-pressure 5.56mm cartridge in a .223 chamber with its much shorter leade. It is generally known that shortening the leade can dramatically increase chamber pressure. In some cases, this higher pressure could result in primer pocket gas leaks, blown cartridge case heads and gun functioning issues.
* The 5.56mm military cartridge fired in a .223 Rem chamber is considered by SAAMI (Small Arm and Ammunition Manufacturers Institute) to be an unsafe ammunition combination.
Before buying either of these two types of ammunition, always check your gun to find what caliber it is chambered for, then buy the appropriate ammunition. Most 5.56mm rounds made have full metal jacket bullets. Performance bullets - soft points, hollow points, Ballistic Silvertips, etc. - are loaded in .223 Rem cartridges. Firing a .223 Rem cartridge in a 5.56mm-chambered gun is safe and merely gives you slightly reduced velocity and accuracy. However we do not recommend, nor does SAAMI recommend, firing a 5.56mm cartridge in a gun chambered for the .223 Rem as the shorter leade can cause pressure-related problems.
Winchester Law Enforcement Ammunition East Alton Illinois