Using m-16 ammo in my .223 Rem
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STUMP49
New member
Q. What is the difference between 5.56×45mm and .223 Remington ammo?
In the 1950's, the US military adopted the metric system of measurement and uses metric measurements to describe ammo. However, the US commercial ammo market typically used the English "caliber" measurements when describing ammo. "Caliber" is a shorthand way of saying "hundredths (or thousandths) of an inch." For example, a fifty caliber projectile is approximately fifty one-hundredths (.50) of an inch and a 357 caliber projectile is approximately three-hundred and fifty-seven thousandths (.357) of an inch. Dimensionally, 5.56 and .223 ammo are identical, though military 5.56 ammo is typically loaded to higher pressures and velocities than commercial ammo and may, in guns with extremely tight "match" .223 chambers, be unsafe to fire.
The chambers for .223 and 5.56 weapons are not the same either. Though the AR15 design provides an extremely strong action, high pressure signs on the brass and primers, extraction failures and cycling problems may be seen when firing hot 5.56 ammo in .223-chambered rifles. Military M16s and AR15s from Colt, Bushmaster, FN, DPMS, and some others, have the M16-spec chamber and should have no trouble firing hot 5.56 ammunition.
Military M16s have slightly more headspace and have a longer throat area, compared to the SAAMI .223 chamber spec, which was originally designed for bolt-action rifles. 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.
The military chamber is often referred to as a "5.56 NATO" chamber, as that is what is usually stamped on military barrels. Some commercial AR manufacturers use the tighter ".223" (i.e., SAAMI-spec and often labeled ".223" or ".223 Remington") chamber, which provides for increased accuracy but, in self-loading rifles, less cycling reliability, especially with hot-loaded military ammo. A few AR manufacturers use an in-between chamber spec, such as the Wylde chamber. Many mis-mark their barrels too, which further complicates things. You can generally tell what sort of chamber you are dealing with by the markings, if any, on the barrel, but always check with the manufacturer to be sure.
Typical Colt Mil-Spec-type markings: C MP 5.56 NATO 1/7
Typical Bushmaster markings: B MP 5.56 NATO 1/9 HBAR
DPMS marks their barrels ".223", though they actually have 5.56 chambers.
Olympic Arms marks their barrels with "556", with some additionally marked "SS" or "SUM." This marking is used on all barrels, even older barrels that used .223 chambers and current target models that also use .223 chambers. Non-target barrels made since 2001 should have 5.56 chambers.
Armalite typically doesn't mark their barrels. A2 and A4 models had .223 chambers until mid-2001, and have used 5.56 chambers since. The (t) models use .223 match chambers.
Rock River Arms uses the Wylde chamber specs on most rifles, and does not mark their barrels.
Most other AR manufacturers' barrels are unmarked, and chamber dimensions are unknown.
In the 1950's, the US military adopted the metric system of measurement and uses metric measurements to describe ammo. However, the US commercial ammo market typically used the English "caliber" measurements when describing ammo. "Caliber" is a shorthand way of saying "hundredths (or thousandths) of an inch." For example, a fifty caliber projectile is approximately fifty one-hundredths (.50) of an inch and a 357 caliber projectile is approximately three-hundred and fifty-seven thousandths (.357) of an inch. Dimensionally, 5.56 and .223 ammo are identical, though military 5.56 ammo is typically loaded to higher pressures and velocities than commercial ammo and may, in guns with extremely tight "match" .223 chambers, be unsafe to fire.
The chambers for .223 and 5.56 weapons are not the same either. Though the AR15 design provides an extremely strong action, high pressure signs on the brass and primers, extraction failures and cycling problems may be seen when firing hot 5.56 ammo in .223-chambered rifles. Military M16s and AR15s from Colt, Bushmaster, FN, DPMS, and some others, have the M16-spec chamber and should have no trouble firing hot 5.56 ammunition.
Military M16s have slightly more headspace and have a longer throat area, compared to the SAAMI .223 chamber spec, which was originally designed for bolt-action rifles. 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.
The military chamber is often referred to as a "5.56 NATO" chamber, as that is what is usually stamped on military barrels. Some commercial AR manufacturers use the tighter ".223" (i.e., SAAMI-spec and often labeled ".223" or ".223 Remington") chamber, which provides for increased accuracy but, in self-loading rifles, less cycling reliability, especially with hot-loaded military ammo. A few AR manufacturers use an in-between chamber spec, such as the Wylde chamber. Many mis-mark their barrels too, which further complicates things. You can generally tell what sort of chamber you are dealing with by the markings, if any, on the barrel, but always check with the manufacturer to be sure.
Typical Colt Mil-Spec-type markings: C MP 5.56 NATO 1/7
Typical Bushmaster markings: B MP 5.56 NATO 1/9 HBAR
DPMS marks their barrels ".223", though they actually have 5.56 chambers.
Olympic Arms marks their barrels with "556", with some additionally marked "SS" or "SUM." This marking is used on all barrels, even older barrels that used .223 chambers and current target models that also use .223 chambers. Non-target barrels made since 2001 should have 5.56 chambers.
Armalite typically doesn't mark their barrels. A2 and A4 models had .223 chambers until mid-2001, and have used 5.56 chambers since. The (t) models use .223 match chambers.
Rock River Arms uses the Wylde chamber specs on most rifles, and does not mark their barrels.
Most other AR manufacturers' barrels are unmarked, and chamber dimensions are unknown.
Jack Roberts
Moderator - Deceased
STUMP49,
I totally disagree. Except for the throat length and taper the differences between the two are less than the allowable tolerances. The throat length is immaterial because any ammo that will fit in a magazine will never get close to either throat.
The headspace is the same just with a tiny bit more tolerance for the 5.56.
I am looking at the actual chamber prints when I say this not something copied and pasted off the internet.
The proof is the fact that 100s of millions of rounds are shot interchangeably every year with no reported problems.
Jack
I totally disagree. Except for the throat length and taper the differences between the two are less than the allowable tolerances. The throat length is immaterial because any ammo that will fit in a magazine will never get close to either throat.
The headspace is the same just with a tiny bit more tolerance for the 5.56.
I am looking at the actual chamber prints when I say this not something copied and pasted off the internet.
The proof is the fact that 100s of millions of rounds are shot interchangeably every year with no reported problems.
Jack
YES it is okay, I can't believe how often this question comes up, maybe just a bunch of new AR shooters lately. I wish I knew how many thousands of rounds of military ammo I have shot thru my AR's and not one has ever had a problem feeding the stuff or burning out barrels. Can't say it's as accurate as match ammo or homemade stuff but it shoots good and, well, use to be cheap.
Wingman26
New member
Quote:
Is it OK to use military ammo in my 223 rem?
To make any sense of the question we really need more information, is it an AR or a bolt, or something else? Some dealers sell AR's calling them 223, when they are really 5.56 NATO, the caliber should be marked on the barrel.
If you have an AR, then the surplus ammo is normally fine, if you have anything else, take a pass.
Is it OK to use military ammo in my 223 rem?
To make any sense of the question we really need more information, is it an AR or a bolt, or something else? Some dealers sell AR's calling them 223, when they are really 5.56 NATO, the caliber should be marked on the barrel.
If you have an AR, then the surplus ammo is normally fine, if you have anything else, take a pass.
CatShooter
New member
Quote:
Jack I am just going by what I read and I guess if I wasnt sure I would go with the manufacturers recommendations and be safe.....stump
Stump... you are wrong.
When someone asks for advice, it should come from the real world... people that have done it - any idjit can read stuff and pass it on, trying to look like an expert.
Plus, your introduction "Theses" is rife with errors, and items taken out of contest because you didn't understand what you were reading.
There have been hundreds of millions of rounds of military surplus 5.56/223 ammo shot in civilian bolt, pump, and semi-auto rifles... and all of them work fine, without a bit of danger or other hazards.
The only problem that has ever come up is when late production 5.56 ammo with long, heavy bullets, is shot in .223 rifles with 14" twists, the bullets tumble because the twist is not fast enough to stabilize the bullets... and even in this case, there is absolutely no danger or hazard.
.
Jack I am just going by what I read and I guess if I wasnt sure I would go with the manufacturers recommendations and be safe.....stump
Stump... you are wrong.
When someone asks for advice, it should come from the real world... people that have done it - any idjit can read stuff and pass it on, trying to look like an expert.
Plus, your introduction "Theses" is rife with errors, and items taken out of contest because you didn't understand what you were reading.
There have been hundreds of millions of rounds of military surplus 5.56/223 ammo shot in civilian bolt, pump, and semi-auto rifles... and all of them work fine, without a bit of danger or other hazards.
The only problem that has ever come up is when late production 5.56 ammo with long, heavy bullets, is shot in .223 rifles with 14" twists, the bullets tumble because the twist is not fast enough to stabilize the bullets... and even in this case, there is absolutely no danger or hazard.
.
STUMP49
New member
catshooter
1. not a idjit.
2. I am NO expert. Plus I dont claim to be.
I just read something and passed it on and the person can do what ever they please with it. The person also has the right to listen to what you have to say and do with that what ever he wants.
I wasnt wrong the guy that wrote maybe is...the only wrong I did was maybe post it......I posted it just to put the throught on the table and have others post there comments.
This is a learning board and there are alot of people here that know alot, thats why I come to this board. Jack disagreed, but did it in a professional manner, thanks Jack.
1. not a idjit.
2. I am NO expert. Plus I dont claim to be.
I just read something and passed it on and the person can do what ever they please with it. The person also has the right to listen to what you have to say and do with that what ever he wants.
I wasnt wrong the guy that wrote maybe is...the only wrong I did was maybe post it......I posted it just to put the throught on the table and have others post there comments.
This is a learning board and there are alot of people here that know alot, thats why I come to this board. Jack disagreed, but did it in a professional manner, thanks Jack.
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lyotehunter
New member
it is okay to shoot but not worth the time and effort to reload.don't leave the brass, recycle it. the price is up.
CatShooter
New member
Quote:
"... Jack disagreed, but did it in a professional manner, thanks Jack.
That's because Jack is a very nice person, has good table manors, and probably went to the "Martha Stewart's Finishing School and Institute of Diplomatic Arts".
I, on the other hand, grew up in the streets of NYC, where BS artists got called out on the spot, and maybe (if they were not an idjit), they would learn to not give opinions on stuff they knew nothing about.
Each style works, on different people... obviously, you do not respond to the diplomatic style, and so maybe a different style will "learn you somfin".
Opinions about something you know nothing about, are NOT the same as experence... they never were, and they never will be.
.
"... Jack disagreed, but did it in a professional manner, thanks Jack.
That's because Jack is a very nice person, has good table manors, and probably went to the "Martha Stewart's Finishing School and Institute of Diplomatic Arts".
I, on the other hand, grew up in the streets of NYC, where BS artists got called out on the spot, and maybe (if they were not an idjit), they would learn to not give opinions on stuff they knew nothing about.
Each style works, on different people... obviously, you do not respond to the diplomatic style, and so maybe a different style will "learn you somfin".
Opinions about something you know nothing about, are NOT the same as experence... they never were, and they never will be.
.
Quote:
Is it OK to use military ammo in my 223 rem?
Here is a discussion of the risk - you decide.
First, Mil spec 5.56 ammo is loaded to higher pressure than SAAMI .223: 50,000 cup -vs- 60,000 cup. 5.56 brass is thicker in order to handle the extra pressure.
Second, military 5.56 chambers have a longer leade or freebore ahead of the chamber than the SAAMI .223
Problem: Take a high pressure M193 or M855 round with an OAL of 2.26". Place it in a tight match .223 chamber (with minimum chamber dimensions) and a short leade for seating light bullets against the rifling. You going to pull the trigger?
Factory chamber - Probably ok like others here have said. Custom, benchrest or target/varmint chamber like in the example above? I wouldn't...
Is it OK to use military ammo in my 223 rem?
Here is a discussion of the risk - you decide.
First, Mil spec 5.56 ammo is loaded to higher pressure than SAAMI .223: 50,000 cup -vs- 60,000 cup. 5.56 brass is thicker in order to handle the extra pressure.
Second, military 5.56 chambers have a longer leade or freebore ahead of the chamber than the SAAMI .223
Problem: Take a high pressure M193 or M855 round with an OAL of 2.26". Place it in a tight match .223 chamber (with minimum chamber dimensions) and a short leade for seating light bullets against the rifling. You going to pull the trigger?
Factory chamber - Probably ok like others here have said. Custom, benchrest or target/varmint chamber like in the example above? I wouldn't...
Jack Roberts
Moderator - Deceased
As a rule brass thickness is the same. Individual lots may vary in either direction. Just weigh the empty cases to see which is thicker. Thicker military brass is an old wives tale from back when 30-06 was used in machine guns.
223 is not restricted to 50,000 CUP by SAAMI. I can't find the figures right now but know it is at least 54,000 CUP.
Hundreds of millions of rounds shot interchangeably every year with no problems indicates they are interchangeable.
Jack
223 is not restricted to 50,000 CUP by SAAMI. I can't find the figures right now but know it is at least 54,000 CUP.
Hundreds of millions of rounds shot interchangeably every year with no problems indicates they are interchangeable.
Jack
CatShooter
New member
Quote:
First, Mil spec 5.56 ammo is loaded to higher pressure than SAAMI .223: 50,000 cup -vs- 60,000 cup. 5.56 brass is thicker in order to handle the extra pressure.
Not true. I have the current SAAMI set of books, and the figures for the 223 are ~64,000 psi. They were raised a long time ago.
Quote:
Second, military 5.56 chambers have a longer leade or freebore ahead of the chamber than the SAAMI .223
That is not a safety issue, that is a reliability issue - all military firearms have sloppy chambers and throats so they don't jam or fail to fire when dirty.
Quote:
Problem: Take a high pressure M193 or M855 round with an OAL of 2.26". Place it in a tight match .223 chamber (with minimum chamber dimensions) and a short leade for seating light bullets against the rifling. You going to pull the trigger?
That's an extreme, and bogus example.
Who is going to have a tight, minimum chamber cut in a custom match rifle, and then waste the barrel with mil-surp ammo??
Quote:
Factory chamber - Probably ok like others here have said. Custom, benchrest or target/varmint chamber like in the example above? I wouldn't...
Neither would any owner of such a barrel... but it is apples and oranges.
If it's the "safety issue" that the Chicken Littles here think it is, where are the reports of guns and shooters being damaged
Just ain't there!
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First, Mil spec 5.56 ammo is loaded to higher pressure than SAAMI .223: 50,000 cup -vs- 60,000 cup. 5.56 brass is thicker in order to handle the extra pressure.
Not true. I have the current SAAMI set of books, and the figures for the 223 are ~64,000 psi. They were raised a long time ago.
Quote:
Second, military 5.56 chambers have a longer leade or freebore ahead of the chamber than the SAAMI .223
That is not a safety issue, that is a reliability issue - all military firearms have sloppy chambers and throats so they don't jam or fail to fire when dirty.
Quote:
Problem: Take a high pressure M193 or M855 round with an OAL of 2.26". Place it in a tight match .223 chamber (with minimum chamber dimensions) and a short leade for seating light bullets against the rifling. You going to pull the trigger?
That's an extreme, and bogus example.
Who is going to have a tight, minimum chamber cut in a custom match rifle, and then waste the barrel with mil-surp ammo??
Quote:
Factory chamber - Probably ok like others here have said. Custom, benchrest or target/varmint chamber like in the example above? I wouldn't...
Neither would any owner of such a barrel... but it is apples and oranges.
If it's the "safety issue" that the Chicken Littles here think it is, where are the reports of guns and shooters being damaged
Just ain't there!
.
Christopher
New member
Just last month, if my memory serves me correctly, the NRA had an article on just that question. The author, thinking it was Bryce Townsley, qouted an industry expert who basically said the same thing as Stump49.
See, you aint such an ijit after all. Even the big boys spill that ink.
That said my AR had problems interchanging 223 handloads and Lake City rounds at first. Some of the issue was cheap magizines but the chamber tightness was a factor, too. This was on a Model 1 upper and the chamber could have very easily been rough. But now it feeds both with no issue. I'm not too worried about the rifle going "boom" in my hands.
BTW, Jack, about 15 years ago I did weigh military 30/06 brass from the 50's against the Remmington brass I had. I was heavier.?. Shoots good, though.
See, you aint such an ijit after all. Even the big boys spill that ink.
That said my AR had problems interchanging 223 handloads and Lake City rounds at first. Some of the issue was cheap magizines but the chamber tightness was a factor, too. This was on a Model 1 upper and the chamber could have very easily been rough. But now it feeds both with no issue. I'm not too worried about the rifle going "boom" in my hands.
BTW, Jack, about 15 years ago I did weigh military 30/06 brass from the 50's against the Remmington brass I had. I was heavier.?. Shoots good, though.
Wingman26
New member
No matter what the "internet message board experts" might think, there is only one authority on the subject, SAAMI, and SAAMI calls it unsafe.
http://www.saami.org/Unsafe_Combinations.cfm
So who has the most credibility, SAAMI or the message board experts? The entire industry relies on SAAMI, so do I.
http://www.saami.org/Unsafe_Combinations.cfm
So who has the most credibility, SAAMI or the message board experts? The entire industry relies on SAAMI, so do I.
reb8600
Retired PM Staff
Quote:
Stump... you are wrong.
When someone asks for advice, it should come from the real world... people that have done it - any idjit can read stuff and pass it on, trying to look like an expert.
The only problem that has ever come up is when late production 5.56 ammo with long, heavy bullets, is shot in .223 rifles with 14" twists, the bullets tumble because the twist is not fast enough to stabilize the bullets... and even in this case, there is absolutely no danger or hazard.
.
What a stupid statement. You tell him that what someone writes is not good advice and then you proceed to pass on some you read.
Here is one for you. I know someone that grabbed my 270 shells one morning to go hunting with their 30-06. They fired 4 rounds through it. Now according to your advice that
"it should come from the real world... people that have done it". Since he did it with no harm, if he tells everyone it is safe then his word is better than someone who says they read it is not safe. His actions of grabing the wrong shells was not smart but your comment is plain stupid.
I see a lot of advice from you that I would bet is nothing more than something you read. Not from your real world experience.
Quote:
Quote:
First, Mil spec 5.56 ammo is loaded to higher pressure than SAAMI .223: 50,000 cup -vs- 60,000 cup. 5.56 brass is thicker in order to handle the extra pressure.
Not true. I have the current SAAMI set of books, and the figures for the 223 are ~64,000 psi. They were raised a long time ago.
I believe this is something you read and are writing here. Is this to make you look like an "expert" or is that from your real world experience?
Stump... you are wrong.
When someone asks for advice, it should come from the real world... people that have done it - any idjit can read stuff and pass it on, trying to look like an expert.
The only problem that has ever come up is when late production 5.56 ammo with long, heavy bullets, is shot in .223 rifles with 14" twists, the bullets tumble because the twist is not fast enough to stabilize the bullets... and even in this case, there is absolutely no danger or hazard.
.
What a stupid statement. You tell him that what someone writes is not good advice and then you proceed to pass on some you read.
Here is one for you. I know someone that grabbed my 270 shells one morning to go hunting with their 30-06. They fired 4 rounds through it. Now according to your advice that
"it should come from the real world... people that have done it". Since he did it with no harm, if he tells everyone it is safe then his word is better than someone who says they read it is not safe. His actions of grabing the wrong shells was not smart but your comment is plain stupid.
I see a lot of advice from you that I would bet is nothing more than something you read. Not from your real world experience.
Quote:
Quote:
First, Mil spec 5.56 ammo is loaded to higher pressure than SAAMI .223: 50,000 cup -vs- 60,000 cup. 5.56 brass is thicker in order to handle the extra pressure.
Not true. I have the current SAAMI set of books, and the figures for the 223 are ~64,000 psi. They were raised a long time ago.
I believe this is something you read and are writing here. Is this to make you look like an "expert" or is that from your real world experience?
CatShooter
New member
Quote:
Quote:
Stump... you are wrong.
When someone asks for advice, it should come from the real world... people that have done it - any idjit can read stuff and pass it on, trying to look like an expert.
The only problem that has ever come up is when late production 5.56 ammo with long, heavy bullets, is shot in .223 rifles with 14" twists, the bullets tumble because the twist is not fast enough to stabilize the bullets... and even in this case, there is absolutely no danger or hazard.
.
What a stupid statement. You tell him that what someone writes is not good advice and then you proceed to pass on some you read.
Here is one for you. I know someone that grabbed my 270 shells one morning to go hunting with their 30-06. They fired 4 rounds through it. Now according to your advice that
"it should come from the real world... people that have done it". Since he did it with no harm, if he tells everyone it is safe then his word is better than someone who says they read it is not safe. His actions of grabing the wrong shells was not smart but your comment is plain stupid.
I see a lot of advice from you that I would bet is nothing more than something you read. Not from your real world experience.
Quote:
Quote:
First, Mil spec 5.56 ammo is loaded to higher pressure than SAAMI .223: 50,000 cup -vs- 60,000 cup. 5.56 brass is thicker in order to handle the extra pressure.
Not true. I have the current SAAMI set of books, and the figures for the 223 are ~64,000 psi. They were raised a long time ago.
I believe this is something you read and are writing here. Is this to make you look like an "expert" or is that from your real world experience?
From real world experence. I was a commercial loader for several years, and still own a pressure gun.
If you want to see it, just drop by some time.
.
Quote:
Stump... you are wrong.
When someone asks for advice, it should come from the real world... people that have done it - any idjit can read stuff and pass it on, trying to look like an expert.
The only problem that has ever come up is when late production 5.56 ammo with long, heavy bullets, is shot in .223 rifles with 14" twists, the bullets tumble because the twist is not fast enough to stabilize the bullets... and even in this case, there is absolutely no danger or hazard.
.
What a stupid statement. You tell him that what someone writes is not good advice and then you proceed to pass on some you read.
Here is one for you. I know someone that grabbed my 270 shells one morning to go hunting with their 30-06. They fired 4 rounds through it. Now according to your advice that
"it should come from the real world... people that have done it". Since he did it with no harm, if he tells everyone it is safe then his word is better than someone who says they read it is not safe. His actions of grabing the wrong shells was not smart but your comment is plain stupid.
I see a lot of advice from you that I would bet is nothing more than something you read. Not from your real world experience.
Quote:
Quote:
First, Mil spec 5.56 ammo is loaded to higher pressure than SAAMI .223: 50,000 cup -vs- 60,000 cup. 5.56 brass is thicker in order to handle the extra pressure.
Not true. I have the current SAAMI set of books, and the figures for the 223 are ~64,000 psi. They were raised a long time ago.
I believe this is something you read and are writing here. Is this to make you look like an "expert" or is that from your real world experience?
From real world experence. I was a commercial loader for several years, and still own a pressure gun.
If you want to see it, just drop by some time.
.