Home Forums Hunting & Shooting AR and Tactical Rifles 223-5.6 Difference?

I have several prints and only see freebore as the difference.

The pressure is read differently, I've read, with the 5.56 taken further forward. If I can remember where I saw it, I can elaborate a bit if it would help.

Basic rule is supposedly .223 is safe in 5.56 chamber, but not always conversely because of that throating difference. The Wilde chamber is a compromise.

Generally that's what I've read. Throat dimensions for the 5.56 and the pressures. 223 rem 55k psi. 5.56mm 60 something psi. It's on Ramshot's load data.

5.56 pressure is 62,350 psi as per Ramshot load data. http://www.accuratepowder.com/wp-content/uploads/2018/11/WPHandloading-Guide-7.0-Web-REV.pdf

Freebore is the big difference, but throat diameter is usually a little larger on the 5.56 spec, as well as slightly looser neck and chamber dimensions. (there are exceptions, "usually" being the key word). The Wylde chamber combines the long freebore (enabling hotter loads, much like Weatherby Magnum chambers) with the tighter throat diameter for better accuracy.

I guess it really doesn't matter as I'm doing a bolt rifle I guess.

it's not about the type of action, it's about the bullets you want to use. The old 223 Rem chamber is more suited to light varmint bullets, while the Wylde and 5.56 chambers accommodate heavier bullets. In my experience the Wylde chamber shoots the light varmint bullets very well too and can be loaded to a bit higher velocity because of the freebore.

For building my own barrel as you will, the choice for me would never be between a 223 Rem and 5.56 chamber, it'd be between 223 Rem and 223 Wylde, with my choice in most situations going to the Wylde. Your choice may differ.

Of course there are a number of other match chambers one could choose from as well.

Maybe this is a good time to bring up something I have been puzzling over for quite some time. I've looked over a lot of stuff I've been able to locate on-line regarding the differences between 5.56 and .223 Remington. Some of my observations:

- SAAMI limits .223 Rem to 55000 psi

- the US military utilizes a standard they call SCATP, which includes pressure testing identical to the SAAMI method

- the highest published SCATP pressure figure I have found for 5.56 in US Army documents was a touch over 58000 psi, IIRC

My conclusion for the moment is that the highest pressure American 5.56 ammo would register a little over 58000 psi ala SAAMI. I know there is or was a new M855A1 round loaded hot, but as far as I know the pressure spec was never made public. Based on this, I would assume that an AR15 with 5.56 chamber can handle 58000 [SAAMI] psi, no sweat. On the other hand...

- NATO follows a standard they call EPVAT for 5.56 ammo testing

- EPVAT allows pressures of about 62000 psi

- EPVAT pressure measurement is similar to CIP methods, but not identical

- the CIP pressure limit for .223 Remington seems to be about 62000 psi also

Now...maybe my assumption that European .223 Remington ammo would register 55000 psi if tested to SAAMI methods is faulty. I kinda doubt it though. But here's the problem as I see it: published 5.56 data in American loading manuals lists pressures up to 62000 psi. Comparing it to .223 data in the same manual shows the 5.56 data is considerably hotter, so I would assume that the 5.56 data as published would actually mean pressures measured via SAAMI methods (but I never see this specified, IIRC). The thing is, if they're publishing data that would yield 62000 psi when measure ala SAAMI, what would CIP methods show on that same ammo? I think it would be waaaay over 62000 psi.

The whole thing does not smell right to me. Where is the error in my perspective? What am I not seeing?

Fortunately I have several reamers available and 2 barrels, an 8 twist and a 12 twist. I will be using a Stiller TAC 30 receiver that I picked up at the Shilen Swap Meet. I will set up the 12T for 52-60 grain bullets and 77grn in the 8 twist.
Thanks for the help.

Dimensions from several sources, according to their reamers.

MM

It'll only come as a "surprise" to Texans,that a single RPM and a smidge sense tossed at freebore...will simply do it all and then some.

Someone ask her how she's gonna feed it and at what COAL,because THAT will be just as fhuqking FUNNY.

Hint.................

The original military load for the M193 was very hot, either 28 or 28.5gr of WC844 (aka H335)

YIKES! That would definitely be a hot load. I wonder what the thinking was behind that. Can you provide a link or reference for that info? I'd like to add it to my files if possible.

I wish I had bookmarked all the documents I found and looked at...I did download them, but I don't know how I'd make them available to any interested.

MIL-C-63989C (AR) AMENDMENT 4, 30 January 2001 shows the following change to the previous amendment pertaining to M193:

"3.7 Chamber pressure. The average chamber pressure of the sample cartridges, conditioned at 70 degrees plus or minus 2 degrees F, shall not exceed 58,700 psi. Neither the chamber pressure of an individual sample test cartridge nor the average chamber pressure plus three standard deviations of chamber pressure shall not exceed 64,700 psi."

MIL-C-70460A (AR) AMENDMENT 2, 15 October 1999 shows an almost identical revision for the M855 round.

That is the highest average chamber pressure figure I have ever located in any American military document. I'm not saying there ISN'T a pressure revision document, but if there is I am not aware of it. If it exists, I'd like a copy of it.

I would never use a Wylde in a bolt gun.

I would use the tighter .223 Match or at the loosest, the CLE.

What reamers do you have? Are these going to be mag fed?

TM 43-0001-27
ARMY AMMUNITION DATA SHEETS
SMALL CALIBER AMMUNITION
FSC 1305

Chapter 10, page 3.

http://pdf.textfiles.com/manuals/MILITARY/united_states_army_tm_43-0001-27%20-%2029_april_1994.pdf


Yea, it's hot.

I've loaded 28.5gr of Mil Surpluss WC844 behind 50-55gr bullets before.
In a 5.56 change pressures are fine with Noslers BT, CC etc, not so much with Hornady Vmax....

And don't accidentally drop one into a semi-auto .223 chamber, unless you like picking primers out of your trigger group.

Thanks AS...I do already have that document. They do show a 28.5 grain charge, but they also show a pressure of 52000 psi.

Butch, I hope you are not feeling like I've derailed your thread. I kinda suspect you were thinking more along the lines of chambering reamers when you posted your question, but once the pressure aspect was brought into play I just had to ask my own question. Maybe it should have its own thread, but to be honest I hate to think of how many pissing contests will start if I do post a new thread. We're kinda flying under the radar here, I think.

Although I provide a link to the 1994 version of the TM, the data sheet's the same in the 1967 version. Knowing how much we've learned since 1967, and having loaded it with actual Mil surplus powder (not the commercial equivalent), and comparing it with commercial load data, I'm pretty skeptical of the 52k PSI number.

I'm enjoying it! You know, you kinda pick the fruit out of the chaff.

MM,
What really amazed me, is just how small the differences really are, and how much discussion they generate.

Couple thousands there, couple 10's of thousands there.....How many uses does it take for a reamer to loose a couple thousands, or how many rounds until you .223 chambers wore out to 5.56 dimensions?

The Texan remains stumped...what were the "odds"?!?

Hint...............

Hey Fat Azz! Thanks so much for your valuable info on this thread. My self and my fellow Okie brothers really enjoy the drizzly [bleep] that blows from your mouth. Hint
Butch

bitchlambert,

NOTHING is fhuqking funnier,than a Whining Texan trying to "talk" rifles. Congratulations?!?

Do not "forget",that Imitation is THE most Sincere form of Flattery.

Hint...................

such a shame, Butch is an upstanding fine person and this little [bleep] has to continue to entertain himself. Get a life. Hint.

kchunt495,

Texans TRYING to "talk" rifles,is never not fhuqking HILARIOUS,as your Posts obliviously quantify. In fairness however,you do suck a mean ass. Congratulations?!?

Bless your heart for trying.

Hint................

Hey Fat AZZ, time for you to get out of your cubby hole and show your vast ignorance again . You're fun Fat AZZ. You still feasting on the hog fat that I sent you? Hint hint

bitchlambert,

It's your Imagination,simply Pretend with it as you MUST. Reality is,that you are more than stumped by a "tricky" 223 and schit don't get ANY fhuqking funnier,than a Texan doing her best with a rifle. Congratulations?!?

Bless your heart for trying though!

Hint...................

Oh, I see you finally got your fat AZZ out of bed. Yeah, I'm really stumped. I need to get my BB gun back out and try to remember how many pumps it takes for best accuracy. I just want to thank you for your contribution to this thread and the others that you [bleep] in.

bitchlambert,

Only one needs to supply a Texan with slack on the rope and let them do their BEST...to arrange EPIC Hilarity. Congratulations?!?

If the 223 had barbed wire around it,you'd be doing better.

Bless your heart for TRYING.

Hint.............

Hey fat AZZ, time to get your nasty Azz out of the hog wallow. Big day ahead! Gonna look at all your valuable advice and make a decision. Wait, you didn't have anything to offer, just swill out of your lard AZZ.
Waiting on you as I really enjoy playing with you like a big toy! Hint Hint Grin Grin

bitchlambert,

You are simply a Drooling Dumbfhuqk,mired squarely by your own "abilities",which is simply funnier than fhuqk. Congratulations?!?

I rather enjoy,that your Stupidity is no "act"...as there is simply nothing funnier,than a Texan TRYING to "talk"" rifles.

Bless your heart.

Hint.................

Well Fat AZZ, you got your big Azz up from your pig stye. You have no self esteem and enjoy messing the other folks up to make yourself feel good. Folks know you and we have a big laugh as it seems you have not a clue how pitiful you are.
But on to today. I shopped around and found several metal chisels to chamber my barrel. I'm going to try it in my Oliver wood lathe. It is damn smooth! Yeah, I'm just an old Okie doing what I can.
Hint! Grin!

bitchlambert,

Do NOT steal your own "thunder",because NOBODY could "make" you out to be a DUMBER Fhuqk,than you can...simply by doing your best. Congratulations?!?

Nothing is fhuqking funnier,than a Texan TRYING to "talk" rifles. I'll feign my GREAT "surprise",that your Imagination and Pretend,are yet again taking you to places that do not exist...you "lucky" kchunt.

Bless your heart for trying though,because 223's are "tricky".

Hint................

Chuckle chuckle Fat AZZ, hint hint!!
Ha Ha Ha Ha

Did a little looking around today and I still can find nothing official on the M855A1 cartridge, but I did find MIL-PRF-71208-AR online. The subject of the document is M995 armor piercing 5.56 ammunition, and it states:

The average chamber pressure of cartridges, conditioned at 70 F ± 2ºF (21 C ± 1.1 C), shall be not greater than 59,700 psi (411.6 MPa). Neither the chamber pressure of an individual cartridge nor the average chamber pressure plus
three standard deviations of chamber pressure shall be greater than 64,700 psi (446.1 MPa).

The document also refers to "SCATP-5.56mm (Heavy Bullet) Small Caliber Ammunition Test Procedures for 5.56mm Heavy Bullet Cartridges." This tells me that the pressure testing is done using the same pressure test methods used by SAAMI.

So, now I have seen a reliable 59700 psi average pressure specification. I still have seen nothing approaching 62000 psi in a military document, but I feel a bit more comfortable with warmer loads for my ARs knowing this.

bitchlambert,

It will be a BIG Day in Texas...once you see your first 223 case! Congratulations?!?

Maybe say something in Spanish,to frost the humor of a Texan TRYING to "talk" rifles.

Hint................

Hey little stick. I had better things to do yesterday than correspond with you. My beautiful 10yr old Great Grand Daughter had some of her Art displayed at a library in another city yesterday evening.
I'm sorry , but you are second fiddle to Ava.
River Rider, thanks for your research.

bitchlambert,

A 1st Grade Class,would have a better grip on Mechanics...than you "do". Congratulations?!?

Hint................

Lil Stick, you wonder why you aren't even a piss ant to me.
Too bad you weren't blessed as I.
Ava's self portrait. Pretty good for a 10 year old.


I have more things to do than make an AZZ out of myself on a forum.

bitchlambert,

Are you Bitching or Bragging?

Hint.................

What do you think?

bitchlambert,

I'm HOPING you "think" that is "good"...if only to add more oblivious humor to the equation.

Hint..................

for the casual user such as myself, it' makes no difference

Bitch is simply doing her BEST,which is funnier than fhuqk.

HINT......................

Let see your answer. You are so smart, you have the answer, right?

Trybone,

Pardon my shooting it all and then some.

Hint............

I would ask what sort of low life azzhole would call someone's 10 year old great granddaughter a "Bitch". that stick person answered my question. Absolutely disgusting behavior.

Just received my reamer for the 52grn 12 twist barrel. John Holiger loaned it to me. I will try to have time to chamber it this weekend. I'm looking for a quality glass stock and bottom metal for it.
I will give lil stick a little help, I don't think he was referring to my Great Grand Daughter, but to me. He is just a sick old fat AZZ that has terrible self esteem.

Fug Stick,
If I thought that was an honest apology for the way you shoot your mouth, I would pardon you.

some folks are just like this all the time. They can't help it. Used to have a boss just like it, no matter he was an azz and simply didn't care.

In the end stuff like this sorts itself out.

But I do recall folks coming to twigs side when someone said something about his family, and here he is....

I keep hearing in person he is fine... would have to take proof to prove, and does not excuse rudeness. There was some quote about rude IIRC...

You missed the mark on that one.. He was referring to Butch as the Bitch not his granddaughter... I try not to get involved in these pissing matches..

Should of left that Texas attitude in Texas bud... Or maybe Delta Jct already wearing on you.. I know it would me..

You like stick. I don't like his smart azz attitude. Life is to short.

Thats about all there is for this one and since it works for me I suspect thats all that really matters.

It is a shame that one gets taken to task for trying to live by the golden rule.

Its life man, you all get your panties in a bunch over a guy on the Internet..

Before the internet 223 and 5.56 were interchangeable. While technically the 5.56 CAN be loaded slightly hotter, and has slightly looser tolerances in the chamber they are so close I don't see anyone ever having a serious issue. I've seen much greater variation in factory loads and rifles that were all chambered in 30-06. Heard of and seen more real problems with 30-06 rifles and ammo due to normal variations in manufacturing tolerances than I've seen between 223 and 5.56 rifles and ammo.

The most likely issue is that a semi auto with a 223 chamber might not function as reliable with hotter 5.56 ammo. Just like a Garand won't function with hotter 30-06 loads. But how many semi-auto rifles have 223 chambers.

You are kind of right.

In a bolt gun with factory ammo, you will never see the difference.

In an AR, if you load to max for a 5.56 chamber you will need to back off about a grain in a true .223 chamber, or you will be picking primers out of your trigger group.

So if we're only talking about < 5% difference in maximum charge with a 5.56 versus .223 chamber ... It seems to me that you easily could find that much difference in any two rifles with the same NOMINAL chambering, correct?

In new firearms? I've seen that level of variance in other calibers, especially if we are talking modern firearms vs. worn old military chambers, but that's not what I'm talking about. In the .270, which I've shot a lot I have yet to see one in good working order where I needed back my max loads off 3 whole grains due to a tight sammi spec chamber.

Modern low round count barrels in good working order. Sure you will have some differences, but in my experience, if you don't back your max 5.56 loads off a grain for a .223 chamber you will not like the results.

Thanks.

There are plenty of guns out there marked "223" with 5.56 NATO chambers too.

Read it twice
LMAO. You race around trying to defend a complete POS.
It’s comical!! Pull your own parties out first.

PS I’m not “bagging on you” just noting the hypocrisy.
Carry on clean up guy.

Parties? I wear hot pink g-strings also I’m glad, know one has threatened to fly wherever and deliver ass whoopings. Because that person got there feelers hurt on the internet..

LMAO. I will drive. And I don’t have feelings I’m married.

Bitch parties 😉. PS Hes all but destroyed herself ! the ass whoopn was just to prove what a big mouth snatch she is.

Sad you don’t see it. I’ve no beef with you but if you get in the way expect to be ran over this shït ain’t got brakes.

Uh huh.. Sure thing I guess

Good talk

Oh schit!

Steven Tyler in dis bitch!

Train keep a rollin', all night long.

You hanging out at pineapple point this week flave

Nah.

When I wanna be jerked off I just find somebody with down syndrome.

🤣🤣🤣🤣🤣🤣🤣😂😂😂😁😂😂🤣🤣🤣🍆💦.
Stay out of Washington these be my tards. Ya

Bitch Lambert,

I VERY much enjoy your attempt to "name drop",less citing a SINGLE reamer particular(mainly because you remain a CLUELESS Fhuqk). Congratulations?!?

Hint...…………………….

I have kept 'the hint' on ignore for 10 or more years. I see his crap only when it's quoted. Even if I was off the mark on that one, he is still an azzhole.

DudeLicker,

Imaginary Pretend Ignore is VERY "convincing". Congratulations?!?

Hint...…………………….

Haven't you got the clue yet, Fug Stick? I am going to make your time on this board hell.

Trybone,

It is a fhuqking fascinating Delusion,that you "think" your Stupidity "effects" anyone but yourself. Congratulations?!?


You Whining Clueless Fhuqks are a hoot!

Hint...…………………..

Fug Stick, what makes you think anybody would care if you sucked a Glock today?

Trybone,

Use your Imagination and Pretend to "convince" yourself,that I do not consume your every thought. Congratulations?!?

Hint...…………………..