.223 Case Capacity

[ExtremeX]

[mroels]

Not the most current info but check here

[ExtremeX]

Nice, thanks for that.

I need to find the time to do the test myself with the cases I have on hand.

I’m doing some research to better understand the differences in the brass I use...

I have so much FC 223 head stamp brass but some of the comments about its case capacity, web thickness, and softness have me concerned.

I have been reloading it without issues, but im concerned about how long it’s going to cost before I run into case failure.

Heres another thread I found interesting.

http://www.ar15.com/mobile/topic.html?b=6&f=42&t=276154&page=1

[mark501w]

Federal is one of my favorites, I've found it to be accurate & have never noticed any trouble with it.

[Wrangler John]

Generally, this is a data point that serves little value to the average shooter, including varmint hunters and all but the precision benchrest shooter. To be able to make an objective quality measurement of one brand of brass over another, one would need a testing rig including a pressure barrel that measures peak pressure and curve, chronograph and temperature control. Each load would have to be exactly the same across the brands, exact recipe using one lot of components, case dimensions (especially case headspace) and seating depth to the ogive, and other factors such as neck tension, etc. An extended test may have to allow for chamber throat wear affecting the pressure profile. The test is measuring more factors beyond the metallurgy of the brass, factors more related to loading techniques and maintaining dimensional consistency.

In the semi-automatic rifle the result is less revealing due to mechanical and operational variables of the mechanism. The AR platform with its rather loose connection between upper and lower assembly, plus having the fire control group separated from the bolt carrier-barrel group, and the vibrational inconsistency of the swing hammer vs a linear striker and sear arrangement, make for inherent inconsistencies relative to accuracy. The need for a relatively loose case headspace for function, compared to a precision bolt action also effects brass life, as does the extreme heating of the brass at each firing.

If my experience with Federal brass over the past 40 years is any indication, it is entirely satisfactory and comparable to other brands. I used Federal .223 Remington brass for varmint hunting, and to form into 7mm TCU cases in IHMSA competitive shooting. Federal .30-30 Winchester brass was used in Contender pistols for competition. It was also formed into 7mm IHMSA-Rimmed cases for the Bert Stringfellow designed Wichita Silhouette Pistol, and .30 Herrett and .357 Herrett cases. Federal's .308 Winchester Match cases were necked down and formed into 7mm IHMSA cases, for the Wichita Bolt Action Pistol, with astounding results. Federal's special run of .357 Maximum IHMSA head stamped brass was used for the Ruger revolver and won many trophies, as did their .44 Magnum brass. I also used Federal .22-250 Remington brass for varmint hunting. None of this brass ever caused a problem or failed in use.

That's my dissertation on the subject, I hope it helps.

[JagerDog]

Fed makes good brass. Ultimately they all fail. Most failures pose no immediate risk.

Grains of water is the standard used. It's used in certain internal ballistics calc's.

[FLIGHT762]

Heres another thread I found interesting.
http://www.ar15.com/mobile/topic.htm...=276154&page=1

I had on hand a lot of the older Federal commercial cases (cases were from the 1990's). I had a machinist friend make a gauge as depicted in the AR15.com article. I did find some cases that were below the .175" or under category. I went through the brass and trashed any under .175". The .176"-.184" cases were loaded and noted to leave the brass after firing. This was brass I collected in the 90's and was stored away for years. It was free, so no loss.

I found the newer Federal cases (made in the 2000's) were all fine.

Now, I had the same question as you about case capacities and I've read the 6MM BR article. Since I now have a lot of time on my hands, I sat down one morning and took 17 -.223 / 5.56 cases and carefully checked case capacity with WC-844 powder leveled to the case mouth.

Cases ranged from "TW68" (US Twin Cities5.56) to "LC11" and commercial cases.

The lightest case was a "LC70" @ 91.6 grains with a capacity of 32.1 grains.

The rest of the cases weighed between 93-97 grains and the capacities were all very close, 31.3 to 31.9 grains.

The heaviest cases were "GFL" (Fiocchi)@ 101.5 gr. with a capacity of 31.3 gr., "WIN NT" 5.56" @ 100.1 gr. with a capacity of 30.9 gr., "FNM 80-4" (Portugese) @ 102.8 gr. with a capacity of 30.7 gr., "Frontier 5.56 NATO" @100.4 gr. with a capacity of 30.9 gr., "Hornady 5.56 NATO" 99.1 gr., with a capacity of 31.1 grains.

Generally, the heavier cases had less capacity.

I did the same thing with 17- 7.62 NATO Military brass and 308 Win. commercial cases. I also found the heavier cases had less capacity than the lighter cases.

I've read a lot about this over the years that the consensus is internal case capacity is not related to the weight of the case. My small sampling disputes this.

I'm not a Scientist nor an expert on the subject. This is my hobby I have enjoyed for about 40 years. It keeps me busy and keeps me from throwing my Dollar bills at the girls that spin around those brass poles, so take it for what it's worth.