5.56 m855 penetrator in a .223 rifle?

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slash415

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I just bought a Savage Axis in .223. So far it has been
an awesome gun to shoot. Today I was at Acadmey Sports, they had a box of m855 penetrators for seven bucks. I was wondering if I could safetly fire these rounds from my Axis?
 
Not recommended. 5.56x45 rounds have a higher pressure than .223. You "can" shoot them but it puts excess stress on your rifle.
 
Check with Savage. I have a new Ruger Mini-14 ranch rifle and it's stamped .223 Remington, but the manual and Ruger's web site say all but the target models are both .223 and 5.56.

I think the real difference between .223 and 5.56 is the 5.56 chambers are cut to allow longer bullets. The maximum pressures are about the same, just specified differently.
 
There is another thread about this right now. If you really want to try it, go ahead, it PROBABLY wont damage the rifle. If you experience sticky extraction, or blown primers it is time to stop. The issue is the longer bullets causing overpressure due to engaging the rifling early. I personally would not do it, but your rifle not mine.

http://www.thehighroad.org/showthread.php?t=647716

Edit to add link to thread.
 
I wouldn't want to use those UNLESS it's clearly stamped on the rifle itself. 5.56 ammo has a different leade in the chamber than a 223, and the pressures are greater in the 5.56 than a 223.

I have 2 different rifles that can shoot 223 but only one rifle that I can shoot 5.56 with.
 
the official rule is that no, you should not fire 5.56 in a .223 chamber, but from what I have heard, especially in a bolt gun, it is not really a concern.
 
I found this info helpful.

Much of the confusion in the pressure differences comes from the fact that NATO rounds are tested for pressure at the chamber mouth or barrel and the SAAMI tests it at the chamber.

.223 Remington versus 5.56 mm NATO



These 5.56x45mm NATO cartridges are identical in appearance to .223 Remington. They are, however, not completely interchangeable.
While the 5.56mm NATO and .223 Remington cartridges and chamberings are very similar, they are not identical.
While there is a myth that 5.56 NATO cases are thicker and hence have less capacity than commercial .223 cases, this has been shown to be false. Each brand of case and each manufacturing lot has a slightly different case capacity; 5.56 NATO and .223 commercial cases tend to have nearly identical case capacity when measured using the water test.[6] The NATO specification allows a higher chamber pressure. NATO EPVAT test barrels made for 5.56mm NATO measure chamber pressure at the case mouth, as opposed to the location used by the United States civil standards organization SAAMI. The piezoelectric sensors or transducers NATO and SAAMI use to conduct the actual pressure measurements also differ. This difference in measurement method accounts for upwards of 137.9 megapascals (20,000 psi) difference in pressure measurements. This means the NATO EPVAT maximum service pressure of 430 megapascals (62,000 psi) for 5.56mm NATO, is reduced by SAAMI to 379.21 megapascals (55,000 psi) for .223 Remington.[7] In contrast to SAAMI, the other main civil standards organization C.I.P. defines the maximum service and proof test pressures of the .223 Remington cartridge equal to the 5.56mm NATO.
The 5.56mm NATO chambering, known as a NATO or mil-spec chamber, has a longer leade, which is the distance between the mouth of the cartridge and the point at which the rifling engages the bullet. The .223 Remington chambering, known as SAAMI chamber, is allowed to have a shorter leade, and is only required to be proof tested to the lower SAAMI chamber pressure. To address these issues, various proprietary chambers exist, such as the Wylde chamber (Bill Wylde)[8] or the ArmaLite chamber, which are designed to handle both 5.56mm NATO and .223 Remington equally well. The dimensions and leade of the .223 Remington minimum C.I.P. chamber also differ from the 5.56mm NATO chamber specification.
Using commercial .223 Remington cartridges in a 5.56mm NATO chambered rifle should work reliably, but generally will not be as accurate as when fired from a .223 Remington chambered gun due to the longer leade.[9] Using 5.56mm NATO mil-spec cartridges (such as the M855) in a .223 Remington chambered rifle can lead to excessive wear and stress on the rifle and even be unsafe, and the SAAMI recommends against the practice.[10][11] Some commercial rifles marked as ".223 Remington" are in fact suited for 5.56mm NATO, such as many commercial AR-15 variants and the Ruger Mini-14, but the manufacturer should always be consulted to verify that this is acceptable before attempting it, and signs of excessive pressure (such as flattening or gas staining of the primers) should be looked for in the initial testing with 5.56mm NATO ammunition.[12]
 
I've emptied out plenty of XM193 and M855 to get to the LC brass in a couple of Savage 223's. Neither 556 load takes advantage of the chamber difference. You better believe I inspect the brass, I reload it! There is zero indication of excess pressure.

At $3-4/box when I bought it that was an OK way to get good brass compared to virgin Winchester, not so much at $7/box. Sheesh, you'd think it would be coming down in price!

I've had factory Federal Fusion 270 WSM so hot I got extractor marks on the casehead, I'm more concerned about that kind of factory foul up than any theoretical "it's possible that....."

Maybe that Mk262 stuff loaded with 77gr SMK's takes advantage of the long lede, but until then, show me a 223 rifle blown up with M855. Then I might pay attention to all the hand wringers.

Regards,
Brian in CA
 
In a full sized bolt gun chambered for belted magnums I consider 223 and 5.56 to be the same.

Just because pressures spike beyond what saami would be worried about in a 223 does not mean they spike beyond what an action proofed for 270wby can handle.

posted via mobile device.
 
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Commercial SAAMI-specification .223 chambers have a much shorter throat or leade and less freebore than the military chamber. Shooting 5.56 Mil-Spec ammo in a SAAMI-specification chamber can increase pressure dramatically, up to an additional 15,000 psi or more.

you guys do what you want. this has been covered over and over again, and the general consensus is always to not use 5.56 in a .223 chambered rifle.

so you say you did and nothing happened? good for you. have you ever had a reciever kaboom next to your face? i haven't and am not going to do something to increase those chances, when both ammos are plentiful.

i had someone tell me that you could easily fire 5.45 russian in a 5.56....my response to him was the same....good for you, have fun with that.
 
I've heard from several reputable sources that the Savage rifles are not chambered to SAAMI spec specifically so 5.56 ammo doesn't cause pressure problems. Finding a rifle chambered to strict SAAMI spec is pretty challenging these days.
 
One of my recent consulting gigs was working on an M855 issue at Lake City. That DOES NOT make me a general expert on the issue, but perhaps the following is useful:

The 5.56 does have a longer leade that the 223. However, you will not jam the bullet in the lands if you load M855 in a 223. That's because M855 has to fit in a standard M16 magazine. The M855 Lake City M855 ammo I have measures 2.250". I load longer than that for my bolt action 223.

The pressure standards for 5.56 and 223 are indeed different. They are also measured by different methods. Until we dig down through another layer of dirt, we can't say how the SAAMI spec compares with the NATO spec. SAAMI says 55,000 PSI MAP, and NATO says 62,350. But NATO does their measuring at the case mouth, and SAAMI measures in the middle of the case body. The strength of the brass usually creates about a 5,000 PSI difference, which MIGHT account for most of the difference.

Ramshot's reloading data includes a special section that goes to 62,350 PSI. I'll drop them a note and see if they can shed any light on the issue.

In my case, I don't care a lot... got a 5.56.
 
I've heard from several reputable sources that the Savage rifles are not chambered to SAAMI spec specifically so 5.56 ammo doesn't cause pressure problems. Finding a rifle chambered to strict SAAMI spec is pretty challenging these days.
And that's especially true of rifles with faster twist rates designed to accommodate long, heavy .224 bullets.

OP, try a few rounds and check the brass for pressure signs.
 
you guys do what you want. this has been covered over and over again, and the general consensus is always to not use 5.56 in a .223 chambered rifle.

so you say you did and nothing happened? good for you. have you ever had a reciever kaboom next to your face? i haven't and am not going to do something to increase those chances, when both ammos are plentiful.

i had someone tell me that you could easily fire 5.45 russian in a 5.56....my response to him was the same....good for you, have fun with that.

Can anyone show me one .223 rifle that has blown up from shooting 5.56 in it?
 

From the second link
(The following is just a generalization to demonstrate the concept. DO NOT hold me to the exact numbers as they are not correct and they ignore the difference due to the different methods used to measure chamber pressure.)

What that says is the poster guessed and MADE UP a completely fictional pressure map.

again pressure can spike all it wants. short of a case full of reddot you're not going to cause a savage/ruger77/or rem700 ect the slightest distress with a piece of 223 brass.

17 rem shows us the .223 case head is good for 63K psi all day long.


Again cite one instance of m855 causing a ,223 bolt rifle any distress at all



posted via mobile device.
 
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If you look at the CIP standards for .223 (they are different than the SAAMI standards) they can be directly compared to 5.56 since they use the same pressure measuring method. They specify the same pressure for both, and using the same units (SAAMI pressure for the .223 is in CUP which can't be converted to PSI). The difference is in the leade and freebore of the rifle chamber. 5.56 ammo IS loaded hotter even though the max pressure specified and reached is the same. The longer freebore and shallower leade allow the hotter load to stay within the same pressure limit. Firing that hotter load in a spec .223 chamber with the shorter freebore and more abrupt leade can lead to proof load level pressures. This has been tested and confirmed.
 
Helotaxi, that's the most concise and logical explanation I've ever seen. And it makes sense. Do you you have any references where we can verify this, or is it all from memory?
 
Since 1968 i have fired hundreds of thousands of military 5.56mm rounds
in the chambers of .223 rifles. There have never been any signs of high pressure.

SAAMI waited until millions of surplus 5.56mm rounds hit the market before making their earthshaking revelation.

The question here becomes: Would SAAMI lie to you. My answer is a resounding yes. SAAMI has lied before.

A few years ago SAAMI asked OSHA to revise and consolidate outdated rules for small arms ammunition manufacturing and storage. There was one big problem, SAAMI did this without first consulting the manufacturers.

OSHA drafted a publication and put it out for comment. For nearly 50 years i've been an EOD guy who has stored and used thousands of tons of explosives of all types, consulted with explosive and propellant manufacturers on problems, and written plans for ammunition storage now used by the military of two nations. To those of us familiar with ammunition manufacture and storage there was nothing earthshaking in the proposed publication.

The ammo makers had a fit and complained to SAAMI. SAAMI called the NRA and told them the sky was falling and the world as we know it was about to come to an abrupt end. SAAMI forgot to tell the NRA that they asked for the publication.

The NRA and NSSF, without first reading the proposed new publication, jumped all over OSHA for doing what SAAMI asked them to do. Gunowners got energized, imagined the world was ending and called their congress critters.

Yes, SAAMI would lie to you.

Link:

http://www.thehighroad.org/showthre...&highlight=proposed+new+ammunition+regulation
 
Show me the kaboom from using 5.56mm ammo in the .223 chamber of a gun in good condition. Anyone?

There is one .223 gun i'm familiar with that i would not shoot 5.56mm ammo in; matter of fact i got rid of mine and will never own another one. That is the single shot H@R Handi-Rifle. Some of those guns show pressure signs with commercial .223 ammunition. In 1994, while working close to the H@R plant in MA, i met an H@R gunsmith. i asked a him why their .223 chamber dimensions ranged from huge to extremely tight. It turns out that H@R were re-grinding their reamers.

Several of my .223 guns were made in Europe in the past 10 years. None of those Eurpoean gun makers warn of using 5.56 mm ammo in .223 chambers.

i am not recommending that anyone use military 5.56mm ammunition in a .223 chamber. If you don't feel comfortable doing it then don't.
 
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