Reloading 223 vs 5.56

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D.B. Cooper

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So. I just recently learned what is probably common knowledge to most of you. .223 has a few thousandths shorter neck than 5.56 and, subsequently, lower pressures. (I knew the 223 was a lower pressure cartridge, but I didn't know why.)

This leads me to the question of which cases should one use to reload with. I'm on the fence on reloading this cartridge. I'm told that the 223 is actually more accurate than the 5.56, generally speaking. (And from the little bit of 5.56, both 55 and 62 grain, that I've shot, it has all been less than stellar in accuracy.)

SO...can I load 223 cartridges, using 223 data, into 5.56 brass (range brass pick-ups. My range is literally carpeted with the stuff; it's actually annoying.) and expect acceptable results? (Obviously, I wouldn't load using 5.56 data into a 223 case.)

I'm just toying with the idea of loading one or the other (my gun is chambered 5.56), so just trying to figure out options.
 
To set context: I load .223 for my AR (S&W M&P Sport....i.e. not a high end AR) only for plinking purposes.

I load .223 and 5.56 cases and mix them all together. Once I confirm they're either .223 or 5.56 I treat them all the same.

I'm able to get 1 MOA (or a little under) using this mixed brass....with Hornady 55gr FMJs, H335 powder and CCI SR Mag primers. This is more than good enough (accuracy wise) for my purposes.
 
Brass is brass. Resize to fit your barrel, trim to uniform length (under maximum recommended length), deburr necks and load 'em up. Case manufacturer matters more than the .223 Rem stamp or 5.56 NATO stamp. Work up your loads gradually to determine safe pressure level and accuracy nodes. If you are just loading plinking/blasting ammo, go mild .223 Rem data and don't worry about it.
 
To set context: I load .223 for my AR (S&W M&P Sport....i.e. not a high end AR) only for plinking purposes.

I load .223 and 5.56 cases and mix them all together. Once I confirm they're either .223 or 5.56 I treat them all the same.

I'm able to get 1 MOA (or a little under) using this mixed brass....with Hornady 55gr FMJs, H335 powder and CCI SR Mag primers. This is more than good enough (accuracy wise) for my purposes.

I must be the only one that cant get accuracy for poop from Hornady 55 grain and H335 powder. I still have plenty of both. Loaded oodles of them and maybe 2 moa in several different ARs of mine. Same guns with SMK and Varget, 1 MOA, and with one gun, .5 MOA on a very good day, a dime covered 5. Ballistic advantage barrels of couple different sorts. Havent tried again since I started using Redding Competition die set, maybe I should give another whirl. What powder load are you using? I have tried pretty much from work up to getting slightly hot, no max loads.

Russellc
 
Brass is brass. Resize to fit your barrel, trim to uniform length (under maximum recommended length), deburr necks and load 'em up. Case manufacturer matters more than the .223 Rem stamp or 5.56 NATO stamp. Work up your loads gradually to determine safe pressure level and accuracy nodes. If you are just loading plinking/blasting ammo, go mild .223 Rem data and don't worry about it.
Not all brass is equal. Some if not most Mil brass is heavier than commercial brass and may require a lighter charge.

RussellC,
Your not the only one that could not get H335 to shoot. In my case the barrel would not shoot anything accurately under 62 gr. Did not try H335 again when I worked up a load for the new barrel. For the heavier pills I prefer Varget, and Tac for the lighter ones. I've used CFE223 too in the past.
 
223 has a few thousandths shorter neck than 5.56 and, subsequently, lower pressures. (I knew the 223 was a lower pressure cartridge, but I didn't know why.)
After trimming the necks this is an irrelevant point.

Old 5.56 military brass is usually thicker and has slightly less volume. This just means it needs less powder to achieve the same speeds. I doubt it matters which you use as long as the brass is good quality and the same.
 
So. I just recently learned what is probably common knowledge to most of you. .223 has a few thousandths shorter neck than 5.56 and, subsequently, lower pressures. (I knew the 223 was a lower pressure cartridge, but I didn't know why.)

Not sure about your comment D.B. regarding the "shorter neck". Perhaps you refer to COAL/seating depth? Here's info from Hornady load book. But your comment on the pressures is correct.

20190627_184255.jpg
 
Here is my understanding of the difference between .223 Remington and 5.56x45mm NATO...
  • NATO rounds are loaded to a higher max pressure for the same bullet weight (the actual pressure measurements are different between NATO and SAAMI). NATO rounds are "hotter".
  • NATO cases tend to have (but not always) thicker walls while the external dimensions are identical to to .223 Rem. This means smaller internal volume for the powder. All else being equal, loaded with the same powder charge a NATO cases will generate higher pressures because of the smaller case volume.
  • The 5.56x45mm NATO chamber has a longer lead (aka. throat length = distance the bullet needs to jump before reaching the rifling). This extra room in the NATO chamber allows the building pressure of the ignited powder some room to grow before the bullet meets the resistance of the rifling. It also makes the NATO chamber more reliable in dirty conditions.
2_AR-15-223-vs-556-645x420.jpg

All of the above reasons ADD to the chamber pressure when firing a 5.56 NATO round in a .223 Rem... see below why you DON'T want to do this.

The info I'm referencing comes from this page:
https://gundigest.com/gear-ammo/reloading/ar-15-basics-223-vs-5-56x45-nato

A quote from that page about using XM-193 NATO rounds in a NATO test chamber and a .223 Rem test chamber:
In the 5.56 test barrel, the XM-193 produced 48,000 PSI. A little on the low side, but since it delivered the expected velocity, why should Federal have loaded it any hotter? In the .223 barrel, the same ammo produced 62,000 PSI.

What you DON'T WANT to do:
  • DO NOT use factory 5.56 NATO cartridges in a .223 Rem chamber. It is OKAY to use .223 Rem cartridges in a NATO chamber.
  • DO NOT use .223 Rem max load data in 5.56 NATO cases w/o first working up your loads. The smaller NATO case volume could result in over pressure. A powder charge that is max safe pressure in a .223 Rem case fired in a .223 Rem chamber may cause over pressure when used in a NATO case.
  • DO NOT use 5.56 NATO max load data in a .223 Rem case. The max pressure of a NATO cartridge may still exceed a .223 Rem SAAMI cartridge spec. Some .223 Rem cases actually have smaller internal volumes than NATO cases. Don't assume case volume by make alone.

SO...can I load 223 cartridges, using 223 data, into 5.56 brass (range brass pick-ups. My range is literally carpeted with the stuff; it's actually annoying.) and expect acceptable results? (Obviously, I wouldn't load using 5.56 data into a 223 case.)
Since you have a NATO chamber you can use either factory .223 Rem or factory 5.56 NATO boxed cartridges.

I suggest you sort your cases not only by NATO or .223 Remington, but group by batch/make. I split my LC cases into different piles by the year... LC14 in one pile, LC15 in another. FC cases in another pile; etc. I do this more for better consistency by loading the same charges in similar case batches. If you are looking for precision this is an easy way to get somewhat consistent cases. If these are plinking loads, you do not need to be anywhere near max charges. Keep the charges lower and the same charge can be used in either type cases... after you have worked up the charges in the different cases.

When reloading always work up the charges looking for pressure signs on the fired cases. Start from the suggested starting charge weight or 10% below the max charge... which ever is LOWER. Use load data from multiple sources when possible and consider starting with the LOWEST recommended charges for a given bullet weight! Start low and work your way up. This rule works for any cartridge and bullet weight.

Be careful with the Hodgdon site load data. It tends to be hotter than Hornady load data.
I recently started loading for .308 Win and found that my max charge (worked up my load using 7.62 NATO LC cases) was BELOW the starting charge suggested by the Hodgdon site. The Hodgdon starting charge was only around 6% lower than the listed Max charge. In the end, my Max charge ended up being around the 10% below Max point... 4% below the Hodgdon recommended STARTING charge. The Hornady Max charge for the same weight bullet was BELOW the Hodgdon STARTING charge! This taught me to start closer to the LOWEST recommended starting charge load data I could find.
 
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SO...can I load 223 cartridges, using 223 data, into 5.56 brass (range brass pick-ups. My range is literally carpeted with the stuff; it's actually annoying.) and expect acceptable results?
I am running a Faxon 20" rifle gas 1:8 5.56 barrel, home built rifle. On a Lee SS press, with once-fired LC 5.56 brass, 60gr Hornady V-Max, and almost-book-max charge of H4895, I am getting 1"-1.25" 10-round groups at 100 yards. Mind you, I am not checking runout, weighing bullets or cases, or the like, but I do trim my brass every time, and full-length size. So, to answer your question, yes, I think your quest is attainable.
 
If you are worried about mixing cases, do what I did. I spent about 3 hours weighing empty cases, tabulating the dry weight and water weight. I found LC and Hornady cases had the most volume. I ran .2 grains more powder in them than I did in PPU and A-USA.
I got sick of hearing back back and forth about it so I figured it was time well wasted.
It also taught me sorting by volume is a terrific waste of time.
 
If you have a faster-twist barrel (1:9, 1:8, 1:7), then I bet 69 grain Sierra Match Kings (the non-tipped variety) over Varget will shoot well for you. That combo shoots well in a whole bunch of different rifles, and the SMK is not very sensitive to seating depth. Load to mag length, tune powder weight to gun (best answer is usually near max). I've gotten that load to print sub-MOA 5-shot groups at 300 yards repeatedly.
 
I have a few rifles chambered in 5.56 and one in .223, with twist rates that vary from 1:12 to 1:7

They all shoot pretty well (1 MOA-ish) with 55gr bullets (Hornady soft point) and 25.0gr of H335. Using CCI no 41 mil spec primer. It's nice to have one load that works in multiple rifles.

I use a mix of "commercial" .223 brass and military. Just trim them all to the same length and it's all good. Only issue is with seating primers in some of the military brass... have to remove primer crimp.
 
If you have a faster-twist barrel (1:9, 1:8, 1:7), then I bet 69 grain Sierra Match Kings (the non-tipped variety) over Varget will shoot well for you. That combo shoots well in a whole bunch of different rifles, and the SMK is not very sensitive to seating depth. Load to mag length, tune powder weight to gun (best answer is usually near max). I've gotten that load to print sub-MOA 5-shot groups at 300 yards repeatedly.
mine is 1:9, shoots great. Savage 12FV.

Russellc
 
I'm doing exactly what you want to do. Load .223 using range brass. I've been doing it awhile and have good results. I pick up all of the .223/5.56 brass I see at the range, and there's lots of it. Most people don't bother picking up their brass and it becomes litter (literally).

I load for a .223 precision bolt rifle. I seperate the LC brass out and keep it for my reloads. All of the LC is 5.56 NATO with crimped primers. I have gravitated to 62 grain bullets and AR Comp powder. I have a standard load that gives me excellent results in my rifle. The load came from the Hornady manual for .223 Remington. It's consistently 1 MOA. :thumbup:

I have a Ruger Mini-14 also. Trying to load for 1 MOA, or even 2 MOA, with that rifle is a waste of time. I still love that rifle though and shoot it often.
 
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SO...can I load 223 cartridges, using 223 data, into 5.56 brass (range brass pick-ups. My range is literally carpeted with the stuff; it's actually annoying.) and expect acceptable results? (Obviously, I wouldn't load using 5.56 data into a 223 case.)

I'm just toying with the idea of loading one or the other (my gun is chambered 5.56), so just trying to figure out options.

According to the Hornady 5th Edition manual, you trim the .223 and 5.56 cases to the same length.

If what I've read lately is true...

.223 Wylde fits a .223 Wylde-marked barrel.
5.56 safely fits a 5.56 or .223 Wylde-marked barrel.
.223 Rem. safely fits barrels with all three markings.

But if you're handloading, and you're trimming your .223 and 5.56 cases to the published length, then the only question I see is the Cartridge Overall Length as it applies to feeding through the action, and then accuracy.
 
I'm just toying with the idea of loading one or the other (my gun is chambered 5.56), so just trying to figure out options.

Option one for short range: Mixed brass sized to fit your rifle. Magnum primers. Ball powder (335). Quality light bullet (Sierra 52 or 53’s whatever works best in your rifle) seated mag length.

Option two for farther out: Mixed brass sized to fit your rifle. Standard primers. Stick powder (Varget). Quality heavier bullet (Sierra 69’s maybe longer if your rifle will shoot them well) seated mag length.


Note: In my mind your biggest gain is with a better bullet. You can play with different cases and make small gains. Or you can use better bullets and make larger gains. The next biggest gain is with a powder that works well with your bullet choice and with what you are trying to accomplish with your rifle. As always YMMV and please disregard everything I say if you are a HighMaster.
 
Um, there is no .223 Wylde ammo, just the chambering for barrels. :)

I think that's where all of the confusion exists. Outside case dimensions are the same for .223 Rem and 5.56 NATO. Capacity may be a little different but I've seen information that suggests it isn't always true. If you're working up loads for your rifle and using the same brass (headstamp) it doesn't matter. Hornady has 3 different sections for .223//.223 service rifle//5.56 NATO. The data is different based on two things, chambers and barrels. Different pressures and COL determine how the chambers and barrels are cut. For accuracy I'll tale a .223 Rem cut barrel everyday.
 
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