theotherwaldo
Member
-Actually, the brass for 5.56 ammo is usually a tad longer... .
Conventional Wisdom on .223 and 5.56?
- Thread starter Spats McGee
- Start date
Jim Watson
Member
Take service ammo, pull the FMJ, replace it with a JHP target or JSP hunting bullet of similar weight over the GI powder charge and primer. If you are very finicky, dump the powder and reload it at the average charge weight with less variation than the arsenal did.
Accuracy is not usually as good as carefully prepared handloads but is way better than hardball. Mine with a Sierra SMK in Malaysian surplus cases was about a MOA in my Remington 788.
Larry in wyoming
Member
- Joined
- Dec 10, 2021
- Messages
- 619
Copy!
Thanks!
Thanks!
What brass/ammo manufacturers do is one thing but for reloaders you trim cases to the same for both 223 and 5.56. Plus you use the exact same dies when reloading. Most people will use either 223 or 5.56 brass when reloading along with using 223 load data. Each manufacturer's cases will be different so if you are looking at pushing towards max powder charges or looking for the most accuracy you do need to sort your cases by manufacturer and/or case volume.
alsaqr
Member
This year i will fire 2,500-3,000 rounds of M193 5.56mm ammunition mostly from my bolt action rifles. Will also fire 1,000-1,500 reloads, vast majority will use military cases.
In 1968 i came into a large quantity of 5.56mm ammunition and my .222 Sako was re-bored to .223. That rifle has been re-barreled at least four times. My most accurate .223 is a 26 inch barreled Remington 700 set up by a very competent machinist. For a light rifle the CZ 527 is very accurate.
i believe this was previously mentioned. The M16 and variants have generous chambers because the rifle is capable of full automatic fire. The 7.62mm machine guns have chambers larger than those of a .308 rifle: The cases are difficult to full length re-size.
In 1968 i came into a large quantity of 5.56mm ammunition and my .222 Sako was re-bored to .223. That rifle has been re-barreled at least four times. My most accurate .223 is a 26 inch barreled Remington 700 set up by a very competent machinist. For a light rifle the CZ 527 is very accurate.
i believe this was previously mentioned. The M16 and variants have generous chambers because the rifle is capable of full automatic fire. The 7.62mm machine guns have chambers larger than those of a .308 rifle: The cases are difficult to full length re-size.
It is not just for full auto fire. The 5.56 chamber also allows the rifles to function longer in adverse conditions without jams. The M16A2, M16A4 and M4 Carbines are 3 round burst only. The M16, M16A1, M16A3, and M4A1 are full auto.
Carl N. Brown
Member
.223 Remington cartridge SAAMI specifications were established half a century ago.
Essentially NATO including US DoD have been "wildcatting" 5.56x45mm NATO ever since. Mostly in the direction of heavier bullets and harder primers to withstand manhandled by full auto actions.
My presumption is that .223 Remington 55gr FMJ and M193 5.56x45mm are essentially equivalent. With ammo other than that M193 or XM193 load, you ought to check with manufacturer recommendations.
Essentially NATO including US DoD have been "wildcatting" 5.56x45mm NATO ever since. Mostly in the direction of heavier bullets and harder primers to withstand manhandled by full auto actions.
My presumption is that .223 Remington 55gr FMJ and M193 5.56x45mm are essentially equivalent. With ammo other than that M193 or XM193 load, you ought to check with manufacturer recommendations.
Howland937
Member
Respectfully Mr. @Spats McGee, your question as to the dangers of shooting 5.56 in your rifle have been addressed. If I recall correctly, you're not into handloading/reloading? That narrows the the options to what's available OTC in order to get the most out of your rifle. The majority of ammo that should give you enough consistency to achieve reasonable accuracy won't be stamped 5.56.
Can you shoot it safely? Sure. Use that rifle to burn up your stock of 5.56? You could. Let someone learn to shoot bolt action off a rest without wasting good ammo? Heck yeah.
Just don't think you'll ever get an idea how good your little rifle could be.
Can you shoot it safely? Sure. Use that rifle to burn up your stock of 5.56? You could. Let someone learn to shoot bolt action off a rest without wasting good ammo? Heck yeah.
Just don't think you'll ever get an idea how good your little rifle could be.
tubeshooter
Contributing Member
- Joined
- Aug 15, 2006
- Messages
- 2,143
Respectfully - "an idea how good your little rifle could be" and "has anybody ever damaged a .223 bolt or made it kB using 5.56?" is apples and oranges.
But you are correct - asked and basically answered until the next time it comes up I suppose.
My contribution - I bought a .223 bolt a few years ago and researched the question myself. Decided not to worry about it in my modern gun. Went on to get a true 5.56 gun down the road; problem solved (if there ever was one).
But you are correct - asked and basically answered until the next time it comes up I suppose.
My contribution - I bought a .223 bolt a few years ago and researched the question myself. Decided not to worry about it in my modern gun. Went on to get a true 5.56 gun down the road; problem solved (if there ever was one).
P5 Guy
Member
5.56 vs .223: Long Leades And Short Leades
That chamber dimension for the 5.56 NATO is, in fact, slightly larger than the chamber for the .223 Remington—in order to have the smoothest feeding and ejection, even with a dirty weapon, to best serve as a battlefield implement—but it is the leade dimension that makes the biggest difference. Leade is defined as the area from the bullet's resting place before firing to the point where the rifling is engaged. The shorter the leade dimension, the faster the bullet will engage the rifling, and the faster the pressures can rise to a dangerous level.
By design, a 5.56 NATO chamber has almost twice the leade that a .223 Remington chamber does. This is why a long leade cartridge fired in a shorter leade chamber result in a fast and dangerous pressure spike. Again, firing lower pressure .223 ammo in a 5.56 specific rifle is no issue, but firing higher pressure 5.56 NATO ammo from a .223 Remington chamber is extremely dangerous.
Looking at the actual case dimensions, there will be no discernible differences, even when looking at the SAAMI specifications, or for the dimensions of the reloading dies for the pair of cartridges. Yet, there are subtle differences. Initially, the first dimension that will be different is the wall thickness of the brass. As is the case with most military cartridges, the military NATO case will tend to have thicker walls, resulting in less case capacity, and a correlatively higher pressure given the same powder charge. If the exterior dimensions are identical, a thicker wall dimension must result in a smaller interior volume. That can and will pose a problem for those who reload their ammunition; I highly recommend segregating the cases and treating them differently.
That chamber dimension for the 5.56 NATO is, in fact, slightly larger than the chamber for the .223 Remington—in order to have the smoothest feeding and ejection, even with a dirty weapon, to best serve as a battlefield implement—but it is the leade dimension that makes the biggest difference. Leade is defined as the area from the bullet's resting place before firing to the point where the rifling is engaged. The shorter the leade dimension, the faster the bullet will engage the rifling, and the faster the pressures can rise to a dangerous level.
By design, a 5.56 NATO chamber has almost twice the leade that a .223 Remington chamber does. This is why a long leade cartridge fired in a shorter leade chamber result in a fast and dangerous pressure spike. Again, firing lower pressure .223 ammo in a 5.56 specific rifle is no issue, but firing higher pressure 5.56 NATO ammo from a .223 Remington chamber is extremely dangerous.
Looking at the actual case dimensions, there will be no discernible differences, even when looking at the SAAMI specifications, or for the dimensions of the reloading dies for the pair of cartridges. Yet, there are subtle differences. Initially, the first dimension that will be different is the wall thickness of the brass. As is the case with most military cartridges, the military NATO case will tend to have thicker walls, resulting in less case capacity, and a correlatively higher pressure given the same powder charge. If the exterior dimensions are identical, a thicker wall dimension must result in a smaller interior volume. That can and will pose a problem for those who reload their ammunition; I highly recommend segregating the cases and treating them differently.
alsaqr
Member
Yes, there is this SAAMI myth that 5.56mm cases have thicker walls. This is not true of US produced Lake City 5.56mm cartridge cases. Nor is it true of the TW 67 cases i prefer. All of my carefully prepared accuracy loads use military cases that are individually weighed.
The ogives of 5.56mm bullets of the M193 cartridge sit an average of 15 thousandths of an inch from the rifling of my Remington 700 rifle with it's .223 chamber.
The ogives of 5.56mm bullets of the M193 cartridge sit an average of 15 thousandths of an inch from the rifling of my Remington 700 rifle with it's .223 chamber.
Last edited:
Carl N. Brown
Member
Firing 5.56x45mm NATO or commercial .223 Remington with bullets heavier than 55gr in a SAAMI true .223 Remington chamber is not a good idea because short lead/high pressure warnings.
Even if the barrel chamber and rifle action handles high pressures, there is rate of twist to consider.
Older .223 Remington barrels are rifled to stabilize 40 to 55 grain varmit hunting bullets.
Most 5.56mm barrels are rifled to stabilize 55gr M193 to 62gr M855.
Some .223/5.56 barrels are rifled to stabilize 70gr to 77gr bullets.
Mismatching bullet weight of ammo to rate of twist of rifling can lead to poor accuracy.
Want more confusion? In countries with bans on "military calibers" for civilian use, barrels that are 5.56x45mm NATO spec may be marked .223 Remington for import/export/domestic sales for civilian markets.
Even if the barrel chamber and rifle action handles high pressures, there is rate of twist to consider.
Older .223 Remington barrels are rifled to stabilize 40 to 55 grain varmit hunting bullets.
Most 5.56mm barrels are rifled to stabilize 55gr M193 to 62gr M855.
Some .223/5.56 barrels are rifled to stabilize 70gr to 77gr bullets.
Mismatching bullet weight of ammo to rate of twist of rifling can lead to poor accuracy.
Want more confusion? In countries with bans on "military calibers" for civilian use, barrels that are 5.56x45mm NATO spec may be marked .223 Remington for import/export/domestic sales for civilian markets.
That myth has been busted time and time again. Those if us that reload can easily bust that myth. I have seen plenty of commercial .223 brass that is thicker than NATO 5.56 brass. And some commercial .223 brass will have less case capacity than NATO 5.56 brass.
As far as reloading goes, everyone uses the same .223 dies for both. The differences in case thickness comes into effect when loading close to the maximum powder charges. Also if you look at the many sources for reloading data, most will only list data for .223. For those of us reloading for the best accuracy, then we will weigh cases and also check case capacity no matter if the bottoms are stamped 223 or 5.56.
There seems to be a lot of wisdom in this thread, but some confounding factors as well. I don't think this is a safety issue so much as an accuracy issue. If you want best accuracy out of the that sweet little Howa, feed it the ammunition designated on the barrel. Once you have some history with that, try a few rounds of 5.56 and see how accuracy compares. I suspect it will tell you what works best. There is risk in everything we do, but Howa builds solid guns. A few rounds won't compromise it.
I will recommend casting the chamber, checking the twist, and asking yourself why you bought this rifle. If you want an accurate rifle, you can generally do better than military loads. If you just want handy, there may be other solutions that will work better for you. If the accuracy isn't what you hoped but you like the rifle, just ream to Wylde dimensions and don't give it a second thought.
You know what free advice is worth! Carry on!
I will recommend casting the chamber, checking the twist, and asking yourself why you bought this rifle. If you want an accurate rifle, you can generally do better than military loads. If you just want handy, there may be other solutions that will work better for you. If the accuracy isn't what you hoped but you like the rifle, just ream to Wylde dimensions and don't give it a second thought.
You know what free advice is worth! Carry on!
Nature Boy
Member
- Joined
- Apr 21, 2015
- Messages
- 8,255
Maybe someone could help me out here. If I wanted to sit down at my loading bench and make a 5.56 NATO round, what specs would I use that would differentiate it from a 223?
You could load to a higher potential pressure within SAAMI specs for the 5.56 than you could within SAAMI specs for the 223. You could also load it to 22 hornet levels as well. The case is not the problem, so long as length and internal volume is controlled. Here's the SAAMI interchangeability tables:
https://saami.org/wp-content/uploads/2022/11/SAAMI-Generally-Accepted-Firearms-and-Ammunition-Interchangeability-10-8-2021.pdf
More comparison info. My apologies if already linked, but I read most other responses yesterday so may not remember all:
https://www.wingtactical.com/blog/guide-to-5.56/
https://saami.org/wp-content/uploads/2022/11/SAAMI-Generally-Accepted-Firearms-and-Ammunition-Interchangeability-10-8-2021.pdf
More comparison info. My apologies if already linked, but I read most other responses yesterday so may not remember all:
https://www.wingtactical.com/blog/guide-to-5.56/
How is that possible when 5.56 is regulated by C.I.P. Standards and .223 by SAMMI? I just checked and 5.56 is not listed in the SAMMI Centerfire Rifle performance standards so there is no spec.
It shouldn't be a secret by now that pressures are measured by 2 different methods between the governing bodies, and the C.I.P. method gives a higher number than SAMMI in an apples to oranges fashion. Everything that I have read states that when tested on the same basis, the actual pressures are not much different between the 2 cartridge designations.
I've heard that the Hornady manual gives data for both cartridges but I've not personally laid eyes on it. At one point Nosler on-line listed data for both. The difference was .223 data was for bullets under 69 grains, and 5.56 was for 69 gr. and over. I never understood the reasoning of that break down. That didn't last long and now Nosler only gives .223 data for all bullets.
tark
Member
It would also be impossible because the 45 colt is much longer than an ACP round. Wont fit in the magazine, wouldn't feed and the Colt's rim wouldn't fit in the slide's breech face.
Duh !!!
Jim Watson
Member
Three. Military test and standards are somewhat different from either commercial procedure.
Seems to be a veritable tower of Babel. People want answers, people want to help, no one wants anyone to get hurt, and the standards organizations don't speak the same language. There's a thread from 2020 over on Snipershide with similar discord:
https://www.snipershide.com/shootin...ng-safe-to-shoot-5-56-cz-usa-says-so.7001958/
@Laphroaig I indeed find no SAAMI spec for the 5.56, although there is one for the 7.62x39(?!) CIP uses same spec for both cartridges, so European guns should be safe with either cartridge designation. Europeans also use proof houses to ensure manufacturers are up to snuff. Military goes its own way, but since NATO has specs that small arms ammunition must meet to get the stamp, do those meet or exceed the CIP specs? I don't know.
https://www.snipershide.com/shootin...ng-safe-to-shoot-5-56-cz-usa-says-so.7001958/
@Laphroaig I indeed find no SAAMI spec for the 5.56, although there is one for the 7.62x39(?!) CIP uses same spec for both cartridges, so European guns should be safe with either cartridge designation. Europeans also use proof houses to ensure manufacturers are up to snuff. Military goes its own way, but since NATO has specs that small arms ammunition must meet to get the stamp, do those meet or exceed the CIP specs? I don't know.
Jim Watson
Member
I am economically motivated.
I have a couple of good .223s. One varmint, one target. I am not going to spend barrel life on hardball that will not shoot as well as hunting or match ammo.
A friend has a supply of Imitation Army Surplus that he considers good enough for the standing phase of a high power match, saving the Good Stuff for prone.
I have a couple of good .223s. One varmint, one target. I am not going to spend barrel life on hardball that will not shoot as well as hunting or match ammo.
A friend has a supply of Imitation Army Surplus that he considers good enough for the standing phase of a high power match, saving the Good Stuff for prone.
I get it, but it is like - univerally all of a sudden everyone deciding Amps means Volts, and everyone getting confused about why their breaker keeps tripping when they try to draw 120 Amps from a household outlet and having to watch it happen over and over in slow motion.
Last edited:
