.223/5.56 Education

[462]

Qualifiers: My .223 experience is less than a year old.
I'm aware of the differences between, and similarities of, the .223 and 5.56.

Finished processing about 175 pieces of range pickup .223 and 5.56 brass, and it caused me to remember something, and got me to thinking.
Remembered: When I was picking up the .223 Ruger American, earlier in the year, the store manager said he wouldn't be surprised if Ruger chambered their .223s for the 5.56.
Thinking: It makes sense for a rifle manufacturer to use one reamer for both cartridges, and for commercial ammunition manufacturers to load both cartridges to .223 pressure.

I've weighed the cases of many commercial brands and several years of Lake City NATO, and the variances in weight among the commercial brands was about the same as they were compared to Lake City. Does it matter? I didn't check water capacities, though.
So far, my load development has been done with once-fired Winchester USA 5.56 brass.

Comments, input, higher education welcome.

 

[Ian]

I'm not sure what any of the manufacturers are doing anymore as far as their commercial offerings go. The military specifications haven't changed recently as far as I'm aware, so all the brass so marked from a military plant should still be engineered for disintegrating-link machine guns (thick walls and head, waterproofing sealant, staked primers, annealing mark, etc.) unless it is from a reject lot. The only advice I can offer is to sort by headstamp and check the internal case volume of a few from each group.

Chamber reamers are likewise a pig in a poke. I have a printout somewhere of 5.56x45 chamber reamer specifications from about eight different rifle or barrel manufacturers and they are all over the map. Ruger likely uses worn-out surplus M-249 reamers for all their .223/5.56 rifles and wallers it around real good with a hand drill to make sure ANYTHING vaguely 5.56 NATO will chamber.

 

[Tomme boy]

Savage says 556 is ok to use in their guns. Enail Ruger, they will tell you if you can or not. It is all going to depend on how long the throat is.

 

[fiver]

easy enough to pound some soft lead up in there and be sure.

lake city 223 brass is close enough to be just another big-3 case, it isn't anything special, and it isn't anything different,,, really.

 

[JonB]

Somewhere on the interwebs is a photo of various brands of 223/556 brass sliced in half to show a visual of wall/web thickness. It was quite the surprise that the thicknesses were varied greatly in a non-logical way, Some commercial cases were considerably thicker than the average mil surp cases. IIRC, Remington, who were notorious for thin case walls in other calibers (pistol calibers especially), had one of the thickest webs in their 223.

Another tidbit.
I have two DPMS AR-15 clones (both base models), one made in MN when DPMS was self-owned, and the other made in AL by Remlin. Both are marked as 556 chambers. The MN DPMS has a roomy chamber. The Remlin has a short/tight chamber. If a piece of brass is a few thousands over Max length, it will not chamber in the Remlin.

 

[Rick H]

I have .223R/5.56/and 5.56 wylde chambered rifles, I don't shoot military steel core 62gr. greentip bullets out of any of them. I do shoot 55 gr. sierra BT, 55gr. Hornady BT, 60gr. Hornady HP, 65 gr. Sierra BTSP, 55gr Hornady FMJ, and 37gr. calhoon HP's through all of them. I also shoot Federal LC 55gr. m-193 5.56 through all of them.
Two Bolt action Savages, two AR's, and a Mini-14. The two bolts and the Mini are 1-9 twist and the AR's are 1-7. Each rifle has it's preference. The favorite loads for the bolt rifles (both with 55gr Sierra BTSP) are too long to function in the AR magazines but other than that all the ammo is interchangeable.

I mostly use Federal Gold Medal cases because I had something over 5000 once fired cases gifted to me. None of my loads are "book maximum" (well until the new Hornady 9th edition) but are fairly warm.

 

[popper]

Seems like I heard someplace Hornady 223 was LC made. Got a DPMS original AR10 that will chamber MG brass fine - IIRC somebody said Krieger or Bartlien made the barrels.

 

[462]

Savage says 556 is ok to use in their guns. Enail Ruger, they will tell you if you can or not. It is all going to depend on how long the throat is.

I did e-mail Ruger and got the expected and lawyerly-vague answer to not shoot 5.56 in their .223s.

lake city 223 brass is close enough to be just another big-3 case, it isn't anything special, and it isn't anything different,,, really.

Okay, that coincides with my non-scientific findings.

 

[RBHarter]

I don't even want to delve weigh lots . Sort to headstamp and weigh lot if it seems needed .

Unpopular opinion .
Size , ream necks of the 556 and load according headstamp lots .

I've had good success with 225-62 NOE in 4 rifles .

 

[462]

I was given over 400 Winchester 55-grain FMJs and bought 1000 Hornady 55-grain FMJs for an excellent price, so casting is not in the foreseeable future.

The rifle has an 8-twist, and I thought a 62-grain cast bullet would be about perfect.

 

[RBHarter]

Probably a good place to start . The 1-8 will be fine up to about 68 gr in jacketed then it becomes a this rifle will but that one won't .

The 55s if BTFMJ should get you under 2" pretty easily the flat base may put up a fight at first .

Something between 4198&4895 should work nicely and get good speeds and groups .

 

[358156 hp]

I did e-mail Ruger and got the expected and lawyerly-vague answer to not shoot 5.56 in their .223s.


Okay, that coincides with my non-scientific findings.

Interesting. Ruger used to claim that the Mini-14 was perfectly safe with 5.56 military ammo https://www.ruger.com/products/mini14RanchRifle/models.html, and the SR556 is listed as being rated for 5.56 as well . https://www.ruger.com/products/ar556/models.html

Maybe just the American series are .223 only.

 

[462]

Probably a good place to start . The 1-8 will be fine up to about 68 gr in jacketed then it becomes a this rifle will but that one won't .

The 55s if BTFMJ should get you under 2" pretty easily the flat base may put up a fight at first .

Something between 4198&4895 should work nicely and get good speeds and groups .

Yep, both brands are boat tails and 26-grains of IMR 4895 is their accuracy load. However, the Hornady bullet is the more 100-yard accurate.

Interesting. Ruger used to claim that the Mini-14 was perfectly safe with 5.56 military ammo https://www.ruger.com/products/mini14RanchRifle/models.html, and the SR556 is listed as being rated for 5.56 as well . https://www.ruger.com/products/ar556/models.html

Maybe just the American series are .223 only.

There are many American chamberings available, and if the rifle will handle the .22-250's pressure it seems to me that it should be able to handle the 5.56s.
I think Ruger's lawyers are covering the company's butt.

 

[CZ93X62]

The 223 Rem mantra for bolt rifles has always been "Not suitable for 5.56 x 45 loads". It is mostly a throat length & diameter question between commersh 223, 223 Wylde, and 5.56 x 45, inn order here of shortest & narrowest to longest & widest. Specs are all over the map, in any event.

I don't load my 223s/5.56s into red-line areas anyway--when you have two 22-250s and a 243 to reach out on rats with, flooring it with the 223 is a fool's errand. 90% of my 223 loading gets done with Nosler 55 grain Ballistic Tips, with between 25.0-26.0 grains of WW-748. Most book max loads go to the 28.0-28.5 grain ZIP Code. These get almost 2900 FPS in the 16.5" Ruger 77RC, and a bit over 3000 in the Mini-14 (18") and AR-15A2 (20"). In the 24" truck axle, they run a bit over 3100 FPS. These mild loads are the best load in all 4 rifles. Trust me--a jackrabbit or coyote won't know the difference between start speeds of 2875 FPS or 3125 FPS. Both the Ruger bolt gun and the AR-15 truck-axle will shoot in the high .5" to mid-.6" if the user minds his or her steering steps. The Mini and the A2 can't quite break the 1" @ 100 yards threshold, but both use OEM iron sights and my 60+ year old eyeballs might be getting long in the tooth.

 

[Hawk]

My understanding is the 5.56 is the same dimensions as the .233, just loaded to higher pressures.
The 5.56 has a longer throat to handle the higher pressure.
I have a lot of LC 5.56 NATO brass and a lot of other brands of .223 brass.
Weight variations are all over the place with PPU .223 brass being the thickest and heaviest. Enough so, that I have to alter me loads with PPU brass.

 

[358156 hp]

There's always Ned Christiansons 5.56 throat reamer. I've seen one, it's really neat! http://www.m-guns.com/tools.php
It's in the second row, just RT of center. His website search functions are a little different.

 

[david s]

If I remember correctly the case dimensions are the same with SAAMI but the barrel leade is different (longer with the 5.56) to accommodate heavier bullets for the 5.56. And possibly pressure. The European equivalent of SAAMI the CIP doesn't distinguish between the two.

 

[RBHarter]

Correct . CIP has one standard .
SAMMI recognizes at least 4 on the same case dimensions , 223 match , 223 standard , 556 , 223 Wylde . Tight neck , nominal standard , loose neck long throat , nominal neck long throat and leade , in the most remedially minimized way .

 

[462]

I saw it on the Internet (You Tube, actually) so I wouldn't bet more than a ha'-penny on its truthfulness, but the guy said the difference between .223 and 5.56 pressures are due to the placement of the measuring devices. The .223 is measured at some point on the case body, whereas the 5.56 is measured at the neck. The loading is all the same, only a matter of where the pressure is measured. If that's true, (remember that bet) then chamber dimensions are the only difference. Whatever, and onward through the fog . . .

Anyway, the rifle will only be seeing my .223 handloads.

 

[Tomme boy]

Seems like I heard someplace Hornady 223 was LC made. Got a DPMS original AR10 that will chamber MG brass fine - IIRC somebody said Krieger or Bartlien made the barrels.

Hornady Frontier ammo was made at the LC plant with Hornady components. They did this as LC was not running 556 ammo for the Gov't at the time. They had already met the orders for the year. That 556 ammo was also the reason for lots of blown up guns a couple years ago. The casehead failed at the web. The web was not thick enough to still be in the chamber. Every barrel will have a slight bevel at the face. That was where the case head blew out. And it was only the 55gr fmj. There were no other reports of the other ammo doing this. Hornady would never say it was their fault. And it was also very random when it did happen.

If you are not going to load to 60K then don't worry about it. The LC brass actually has more case capacity than much of the commercial brass. The ones to look out for are the PMP and the European made brass. They hold several gr less powders.