5.56 and 223 caliber
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5.56 and 223 caliber
Got a smith ar15 and was wondering if I can shoot 223 ammo, I have 5.56 stamped on barrel. Can I shoot both or just the 5.56 Thanx to all that reply
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Re: 5.56 and 223 caliber
if it says 5.56 you can shoot both. those stamped .223 are not rated for 5.56 pressure.Daltex1 wrote:Got a smith ar15 and was wondering if I can shoot 223 ammo, I have 5.56 stamped on barrel. Can I shoot both or just the 5.56 Thanx to all that reply
Oh yeah, we need a pic!
*CHL Instructor*
"Speed is Fine, but accuracy is final"- Bill Jordan
Remember those who died, remember those who killed them.
"Speed is Fine, but accuracy is final"- Bill Jordan
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Re: 5.56 and 223 caliber
txinvestigator wrote:if it says 5.56 you can shoot both. those stamped .223 are not rated for 5.56 pressure.Daltex1 wrote:Got a smith ar15 and was wondering if I can shoot 223 ammo, I have 5.56 stamped on barrel. Can I shoot both or just the 5.56 Thanx to all that reply
Oh yeah, we need a pic!
It isn't so much a pressure issue as it is a throat length issue. And while
this may result in higher pressures due to constrained bullets, it is all
about length, not pressure. Nato (5.56) is longer than SAAMI (.223).
One or my AR's (Armalite) is stamped 5.56 while the other (Bushmaster)
is stamped .223/5.56. Both shoot both cases fine as long as I ensure that
the max length is within SAAMI standards. I shoot long, heavy 75 gr
Hornady bullets in both with excellent results.
Kind Regards,
Tom
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Re: 5.56 and 223 caliber
http://www.ammo-oracle.com/body.htm#diffTom wrote:txinvestigator wrote:if it says 5.56 you can shoot both. those stamped .223 are not rated for 5.56 pressure.Daltex1 wrote:Got a smith ar15 and was wondering if I can shoot 223 ammo, I have 5.56 stamped on barrel. Can I shoot both or just the 5.56 Thanx to all that reply
Oh yeah, we need a pic!
It isn't so much a pressure issue as it is a throat length issue. And while
this may result in higher pressures due to constrained bullets, it is all
about length, not pressure. Nato (5.56) is longer than SAAMI (.223).
One or my AR's (Armalite) is stamped 5.56 while the other (Bushmaster)
is stamped .223/5.56. Both shoot both cases fine as long as I ensure that
the max length is within SAAMI standards. I shoot long, heavy 75 gr
Hornady bullets in both with excellent results.
Kind Regards,
Tom
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.
*CHL Instructor*
"Speed is Fine, but accuracy is final"- Bill Jordan
Remember those who died, remember those who killed them.
"Speed is Fine, but accuracy is final"- Bill Jordan
Remember those who died, remember those who killed them.
Re: 5.56 and 223 caliber
Cause and effect.txinvestigator wrote:http://www.ammo-oracle.com/body.htm#diffTom wrote:txinvestigator wrote:if it says 5.56 you can shoot both. those stamped .223 are not rated for 5.56 pressure.Daltex1 wrote:Got a smith ar15 and was wondering if I can shoot 223 ammo, I have 5.56 stamped on barrel. Can I shoot both or just the 5.56 Thanx to all that reply
Oh yeah, we need a pic!
It isn't so much a pressure issue as it is a throat length issue. And while
this may result in higher pressures due to constrained bullets, it is all
about length, not pressure. Nato (5.56) is longer than SAAMI (.223).
One or my AR's (Armalite) is stamped 5.56 while the other (Bushmaster)
is stamped .223/5.56. Both shoot both cases fine as long as I ensure that
the max length is within SAAMI standards. I shoot long, heavy 75 gr
Hornady bullets in both with excellent results.
Kind Regards,
Tom
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.
Short chambers can have the effect of higher pressure. I don't know what
commercial ammo your source is comparing, and they don't say. And I
don't know that ALL military ammo has more pressure than ALL
commercial ammo, and I would doubt that is the case based upon my
experience with other commercial loadings.
But the point is the same. You should not assume that 5.56 ammo will be
OK in a .223 chamber for at least the throat length issue.
I take the word of Clint McKee over just about anyone. He says don't do
it because of the throat length. That is good enough for me.
Kind Regards,
Tom
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Re: 5.56 and 223 caliber
Dear tom,Tom wrote:Cause and effect.txinvestigator wrote:http://www.ammo-oracle.com/body.htm#diffTom wrote:txinvestigator wrote:if it says 5.56 you can shoot both. those stamped .223 are not rated for 5.56 pressure.Daltex1 wrote:Got a smith ar15 and was wondering if I can shoot 223 ammo, I have 5.56 stamped on barrel. Can I shoot both or just the 5.56 Thanx to all that reply
Oh yeah, we need a pic!
It isn't so much a pressure issue as it is a throat length issue. And while
this may result in higher pressures due to constrained bullets, it is all
about length, not pressure. Nato (5.56) is longer than SAAMI (.223).
One or my AR's (Armalite) is stamped 5.56 while the other (Bushmaster)
is stamped .223/5.56. Both shoot both cases fine as long as I ensure that
the max length is within SAAMI standards. I shoot long, heavy 75 gr
Hornady bullets in both with excellent results.
Kind Regards,
Tom
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.
Short chambers can have the effect of higher pressure. I don't know what
commercial ammo your source is comparing, and they don't say. And I
don't know that ALL military ammo has more pressure than ALL
commercial ammo, and I would doubt that is the case based upon my
experience with other commercial loadings.
But the point is the same. You should not assume that 5.56 ammo will be
OK in a .223 chamber for at least the throat length issue.
I take the word of Clint McKee over just about anyone. He says don't do
it because of the throat length. That is good enough for me.
Kind Regards,
Tom
I quote sources. You just blah, blah.
Thank you
*CHL Instructor*
"Speed is Fine, but accuracy is final"- Bill Jordan
Remember those who died, remember those who killed them.
"Speed is Fine, but accuracy is final"- Bill Jordan
Remember those who died, remember those who killed them.
Clint McKee is not a "source"? *snort!*
I don't know of anyone more studied nor more expert on the most arcane technical aspects of service rifles, than Clint McKee and Walt Kuleck. This includes SAAMI vs. MILSPEC, variations in chamber sizes and brass specs, and measuring pressure by PSI vs. CUP.
http://www.fultonarmory.com
Kevin
I don't know of anyone more studied nor more expert on the most arcane technical aspects of service rifles, than Clint McKee and Walt Kuleck. This includes SAAMI vs. MILSPEC, variations in chamber sizes and brass specs, and measuring pressure by PSI vs. CUP.
http://www.fultonarmory.com
Kevin
Kevin,KBCraig wrote:Clint McKee is not a "source"? *snort!*
I don't know of anyone more studied nor more expert on the most arcane technical aspects of service rifles, than Clint McKee and Walt Kuleck. This includes SAAMI vs. MILSPEC, variations in chamber sizes and brass specs, and measuring pressure by PSI vs. CUP.
http://www.fulton-armory.com
Kevin
Indeed! But perhaps Tx hasn't heard of him.
Clint built me a carbine that looks perfect and shoots even better.
Also, SAAMI .223 max pressure is 52,000 CUP; 5.56 max pressure is
52,000 PSI. Hmm, now what is that conversion formula?
Oh, right, there isn't one.
But getting back to the original question, yes you can shoot .223 ammo
in a 5.56 marked barrel. And although it has been a long time since I
have talked to folks about it I believe it is Federal that makes a 69 gr
.223 load that was nearly the standard for most service rifle matches.
But then I shot my last match over 5 years ago so I imagine that there
have been some changes/improvements since then.
Thanks Kevin, and you will stay on here after the move North, right?
Kind Regards,
Tom
- stevie_d_64
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I have a Bushmaster A3, that is stamped for both .223 and 5.56
Do I shoot them both??? Or better yet have I shot them both through the same rifle...
Yes...
I have had zero misfeeds (which is unlikely in the first place) or FTF's...With either round...
The only obvious thing I would do is make sure you don't mix and match between the two...I know that could be considered stupid for me to even mention, and in all actuality it may not create a problem...I guess its just a quirky thing about me I suppose...
The makers of ammo I have used through mine have been:
- PMP (South African)
- Lake City
- Federal
I buy in bulk as well...And try to keep about 5K on hand on a rotational useage schedule...
Do I shoot them both??? Or better yet have I shot them both through the same rifle...
Yes...
I have had zero misfeeds (which is unlikely in the first place) or FTF's...With either round...
The only obvious thing I would do is make sure you don't mix and match between the two...I know that could be considered stupid for me to even mention, and in all actuality it may not create a problem...I guess its just a quirky thing about me I suppose...

The makers of ammo I have used through mine have been:
- PMP (South African)
- Lake City
- Federal
I buy in bulk as well...And try to keep about 5K on hand on a rotational useage schedule...
"Perseverance and Preparedness triumph over Procrastination and Paranoia every time.” -- Steve
NRA - Life Member
"Quis custodiet ipsos custodes?"
Μολών λαβέ!
NRA - Life Member
"Quis custodiet ipsos custodes?"
Μολών λαβέ!
Steve,stevie_d_64 wrote:I have a Bushmaster A3, that is stamped for both .223 and 5.56
Do I shoot them both??? Or better yet have I shot them both through the same rifle...
Yes...
I have had zero misfeeds (which is unlikely in the first place) or FTF's...With either round...
The only obvious thing I would do is make sure you don't mix and match between the two...I know that could be considered stupid for me to even mention, and in all actuality it may not create a problem...I guess its just a quirky thing about me I suppose...![]()
The makers of ammo I have used through mine have been:
- PMP (South African)
- Lake City
- Federal
I buy in bulk as well...And try to keep about 5K on hand on a rotational useage schedule...
When I could get it in NC I would buy cases of the PMP for about $75 per
500 rounds. Those days are gone. But now I have an inexhaustable
supply of very good brass. I also picked up a case of IMI (TZZ brass)
back then and have yet to wear out a single piece of it. Really tough stuff.
The PMP is marked .223 REM while the IMI is 5.56mm. Both shot fine in
both of my AR's after ensuring that there wouldn't be a chambering issue.
The PMP with the 55 gr bullet was a better match round than the IMI due
to the IMI having the military SS109/M855 bullet which is not the greatest
for accuracy. Anything over 200 yards would do better with a heavier
bullet, all the way out to 80 grs. I stayed with the Hornady 75's because
I got a big pile of them from a friend who was getting out of the match
shooting business. Little did I know then that I would soon be out of the
match shooting business as well.
Do you shoot matches and if so what do you shoot? Rifle, ammo, etc.?
I hope some of this is helping the original poster with his ammo questions.
One suggestion - save all of your brass whether you currently handload
or not. It makes great gifts for old and new friends.
Kind Regards,
Tom
The South Africans make good brass. I regret not stocking up on PMP .303 British when it was available dirt cheap everywhere. Once the supply dried up, it dried up completely. It was truly surplus; they're not making any more, because they no longer use it.
But I do take care to keep my '80s PMP brass sorted by rifle, so I can reload it multiple times.
Kevin
But I do take care to keep my '80s PMP brass sorted by rifle, so I can reload it multiple times.
Kevin