Reloading 5.56 brass to .223 specifications

[Bonz]

I keep hearing conflicting stories about reloading 5.56 brass to .223 specifications.

"The 5.56 case has thicker walls to handle higher pressures, meaning the interior volume of the case is smaller than that of a .223. This will alter the loading data used when reloading 5.56 brass to .223 specs."

I have loaded a lot of rounds and never had an issue reloading both .223 and 5.56 brass, loaded to .223 specs, and firing in my 5.56 nato AR 15. I never pay attention to whether the brass is 5.56 or .223

Is there a safety issue ?

[nicholst55]

Depending on the individual brass that you have, the 5.56mm brass may actually have a greater case capacity than commercial brass. I tend to stick to Lake City and WCC brass when loading milsurp brass, and I load it interchangeably with (US-made) commercial brass.

[BruceB]

On one occasion I weighed a dozen or more types of assorted .223 and 5.56 brass.

There was NO meaningful weight difference among the various types.

I use the same loads in both military and commercial cases with excellent results.

[N4AUD]

On one occasion I weighed a dozen or more types of assorted .223 and 5.56 brass.

There was NO meaningful weight difference among the various types.

I use the same loads in both military and commercial cases with excellent results.

Same here.

[45fan]

Thanx Bonz I recently got my first AR and was going to ask basically the same question. I have already started picking up range brass and while most is 223 I do have a few 5.56 mixed in.

[Bonz]

Thanx Bonz I recently got my first AR and was going to ask basically the same question. I have already started picking up range brass and while most is 223 I do have a few 5.56 mixed in.

Same here. Most of the brass that I buy is .223 but there definitely is some 5.56 mixed in. I never bothered to check. My AR is chambered in 5.56 Nato so I wasn't worried. And then I started to read different articles on the web. I trust everyone here more than I do on the web.

I also found this article :

What Do You Have?

So, if you own a rifle chambered for the .223 for 5.56, do you know for which caliber it is really chambered?

Many match rifles are chambered in .223 Remington (SAAMI specs) for tighter tolerances, and theoretically better accuracy.

Many of the AR-15’s currently sold on the market are made for the 5.56 NATO cartridge. If you own one of these, you should be fine with any .223 or 5.56 ammunition.

However, ATK dropped this bomb in the bulletin on the .223/5.56:

“It is our understanding that commercially available AR15’s and M16’s – although some are stamped 5.56 Rem on the receiver – are manufactured with .223 chambers.”

So, even if your AR is stamped 5.56, is it really? Check your owner’s manual or call the company directly and make sure you get an answer you feel comfortable with.

As if the confusion regarding the .223 vs 5.56 chambers wasn’t enough, there is a third possibility in the mix, that is being used by at least one major manufacturer. The .223 Wylde chamber is a modified SAAMI-spec .223 chamber that allows for the safe use of 5.56 NATO rounds, but maintains tighter tolerances for better accuracy.

Yeah, yeah… What’s the bottom line?

Here’s the bottom line. If you want to follow the safest possible course, always shoot .223 Remington ammunition. The .223 Rem cartridge will safely shoot in any rifle chambered for the .223 or 5.56.

If you want to shoot 5.56 NATO rounds, make sure you have a rifle designed for the 5.56 military cartridge. Shooting 5.56 in a normal .223 Rem rifle can result in bad things.

[BruceB]

I said, in Post #3, that I use the same loads in both types of brass.

It should be added that I do segregate the rounds by headstamp when boxing them up.... for appearance's sake if nothing else.