5.56/.223 - I just dont get it

[kbourque3375]

There's a couple misconceptions and I'll try to bring them to light. The .223 is not a commercial eq to the 5.56 since it is and has been for some time available to anyone. do not EVER EVER, NEVER fire a 5.56 in a .223 gun. Here's the only differences and I'm going to try to make this simple since most people don't really understand the principles of loading. 1. The 5.56 cartridge has a thicker wall than the .223 because of the difference in pressures created INSIDE the Chamber of the weapon, has nothing to do with internal cartridge pressure. 2. The Throat or what's called the leade is slightly different on the 5.56 and that's basically the distance the bullet travels after ignition into the rifled part of the barrel. Since the 5.56 is just a tad bit longer. Basically, throw everything you've ever heard about the difference between the two out of the window, the two are not the same. They aren't even manufactured the same way, there's a complete different step that has to be taken when loading a 5.56. Ever notice that slight discoloration in the neck of a 5.56? that's due to what's called "flashing". and without this step, upon ignition, the thing would just blow up. If you are building an AR, go with the 5.56 bbl and lower, that way you can shoot either and not have to worry.

[DefensiveCarry.com]

[gasmitty]

There's a couple misconceptions and I'll try to bring them to light. The .223 is not a commercial eq to the 5.56 since it is and has been for some time available to anyone. do not EVER EVER, NEVER fire a 5.56 in a .223 gun. Here's the only differences and I'm going to try to make this simple since most people don't really understand the principles of loading. 1. The 5.56 cartridge has a thicker wall than the .223 because of the difference in pressures created INSIDE the Chamber of the weapon, has nothing to do with internal cartridge pressure. 2. The Throat or what's called the leade is slightly different on the 5.56 and that's basically the distance the bullet travels after ignition into the rifled part of the barrel. Since the 5.56 is just a tad bit longer. Basically, throw everything you've ever heard about the difference between the two out of the window, the two are not the same. They aren't even manufactured the same way, there's a complete different step that has to be taken when loading a 5.56. Ever notice that slight discoloration in the neck of a 5.56? that's due to what's called "flashing". and without this step, upon ignition, the thing would just blow up. If you are building an AR, go with the 5.56 bbl and lower, that way you can shoot either and not have to worry.

Welcome to the forum, but did you realize you were responding to a thread that's been dormant for 4-1/2 years?

[pittypat21]

Welcome to the forum, but did you realize you were responding to a thread that's been dormant for 4-1/2 years?

Haha! I've done that before. Sometimes I don't pay attention to the dates and then realize halfway through a response that, "Oh, this thread is 3 years old!"

[Eagleks]

Probably bears repeating though, for those that may be just getting into buying their first AR or have one and doesn't know the differences.

[dukalmighty]

My Colt Match Target M4 Carbine is clearly marked "Cal. 223". Are you saying it's OK in THIS gun to use 5.56?

What does the barrel say,it's not what is on the lower receiver it's the barrel marking,usually under the handguards it will have chamber 5.56 or 223 and barrel twist 1/7 1/8 1/9 etc

[OldVet]

All I've ever shot in my Rem 788 .223 is reloaded military 5.56 brass. It's not a problem.

Size the 5.56 in in a .223 die, trim to .223 specs, use standard reloading preocedures as to working up to max loads. The slight difference in shoulder angles will be conformed to .223 during the resizing and next firing.

If buying a new AR, the easiset chice is to opt for the 5.56 and eliminate any concerns,

[Kilowatt3]

...

The big danger is in using 5.56 in bolt action rifles or the Ruger Mini 14...

...with a mini-14 in .223, I make sure the Mini doesn't eat any of the 5.56 ammo that I have...

OK, it's a very old thread, but since it's been resurrected...

It bears mention that all Mini-14's with the exception of the Target model are designed for both 5.56 and .223 ammo. This is per the instruction manuals and the Ruger website (and backed up by 30+ years of shooting 5.56 in my Mini-14's).

Ruger has muddied the waters a bit by marking the barrels ".223" instead of "5.56".

Regards,
Jim

[RKflorida]

Glad to see this thread resurrected, and thanks kbourque3375 for the good information. It's new info for me.
I often catch myself getting excited about an topic and ready to type a firestorm only to realize the article is from the last century, and everyone involved is long gone. Unfortunately, I don't always catch myself and end up feeling dopey.

[Exsimguy1]

Except for the annealed neck being confused with some special "flashing" procedure. Almost all rifle brass is annealed the same way that the military stuff is, but the commercial stuff is polished after the fact so it is not apparent and more appealing to the mass's. The mil stuff is left that way as an expedient to manufacture, and also as proof that the annealing process has been done.

A rifle case gets hardened during the forming process, the neck and shoulder area is annealed to allow the area to stretch slightly to allow the tightley secured bullet to release (to the confines of the chamber neck, clearance is required), and the brass to again retract, to allow extraction. Without annealing, cracking would undoubtably occur, fouling (at least) the chamber rapidly.

Terry