[TheOldMan]

I recently purchased my first "black" rifle as was mention in another thread. I do most of my own reloading but have never loaded for 223. I was concerned that there might be differences between the 5.56 and the 223 but found out that you can load to 223 specs and be ok for AR's chambered for 5.56/223. I've checked on this via google search but wanted to double check with some pro's that we have here in this forum.

I've got 1500 rounds of lake city brass coming (once fired and cleaned) to my house and ordered the 223 dies this morning. I just want to make sure that I'm good loading this brass to 223 specs.

[Highpower]

You will be fine with the LC brass. Just remember that it is military brass and will have a slightly reduced internal capacity. Reduce published loads by about 10% and work your way up, watching for signs of excess pressure.

[TheOldMan]

Originally Posted by Highpower

You will be fine with the LC brass. Just remember that it is military brass and will have a slightly reduced internal capacity. Reduce published loads by about 10% and work your way up, watching for signs of excess pressure.

Thank you.. I did read about the case capacity being reduced in the lake city brass. I appreciate the heads up. Would be nice to have a cronograph to work up the loads. I also read that the 5.56 NATO round ran about 10k higher preasure than the standard commercial 223 so there is a little wiggle room. But I can assume preasure rises fairly quickly per grain of powder..?

[robocop10mm]

I have weighed numerous brands of .223/5.56 brass and have found little difference based on caliber. Do not assume that because it has 5.56 stamped on the case head it is thicker (and therefore has less internal volume). Likewise do not assume that it has more volume just because it says .223

Every case is different. Each lot from each maker "should" be relatively close. Lot to lot, it may vary.

FWIW, my tests concluded that Remington brass is the thinnest (weighs the least) and TW is the thickest (weighs the most). WCC seems to be the most consistent.

[Mutabam]

Per robocop, I've found .223 brass to have the same internal capacity as .223 brass; however, 7.62 military brass doesn't have the same case capacity as commercial .308.

[mrm14]

Originally Posted by TheOldMan

Thank you.. I did read about the case capacity being reduced in the lake city brass. I appreciate the heads up. Would be nice to have a cronograph to work up the loads. I also read that the 5.56 NATO round ran about 10k higher preasure than the standard commercial 223 so there is a little wiggle room. But I can assume preasure rises fairly quickly per grain of powder..?

CED Millenium 2 chrono is a pretty good one.

http://www.cedhk.com/shop/products/CED-M2-Chronograph-Set.html

[alsaqr]

I have weighed numerous brands of .223/5.56 brass and have found little difference based on caliber. Do not assume that because it has 5.56 stamped on the case head it is thicker (and therefore has less internal volume). Likewise do not assume that it has more volume just because it says .223

+1

I weigh and segregate the brass for all of my 5.56mm/.223 accuracy re-loads: Been doing that for 40 years. It is a popular myth that US made 5.56mm military brass is heavier (read thicker) than .223 civilian brass. The thickest US made brass is found in American Eagle and Gold Medal cases. Brit 5.56mm military and Lapua cases are very thick.

Go to Brass Weights Comparison.

AR15BARRELS.COM - Technical Documents

[TheOldMan]

Originally Posted by mrm14

CED Millenium 2 chrono is a pretty good one.

CED M2 Chronograph Set

Thanks for the link.. I had been looking at this one also for it's remote capabilities: Shooting Chrony Alpha Master Chronograph

Originally Posted by alsaqr

+1

I weigh and segregate the brass for all of my 5.56mm/.223 accuracy re-loads: Been doing that for 40 years. It is a popular myth that US made 5.56mm military brass is heavier (read thicker) than .223 civilian brass. The thickest US made brass is found in American Eagle and Gold Medal cases. Brit 5.56mm military and Lapua cases are very thick.

Go to Brass Weights Comparison.

AR15BARRELS.COM - Technical Documents

Great site! Thank you. I'd seen one similar to it but it did not have the spreadsheet comparisons like your linked site had.

[alsaqr]

I've been firing 5.56mm military ball ammo in .223 chambered rifles for over 40 years with no problems at all. There are several SAAMI myths concerning the alleged differences between .223 vs 5.56mm ammo pressures, case
thickness, etc. The US 5.56mm military M193 ball round generates 52,000 psi. See page 10-3 US Army TM 43-0001-27:

ammo data sheets small caliber firearms


SAAMI waited for 30 years before warning us of the "dangers" of firing 5.56mm military ball ammo in .223 chambers. This "warning" came at the same time the US market was flooded with 5.56mm military surplus ammo.

There are about a dozen different .223/5.56mm chambers. Here are the dimensions of eight of them:

http://www.ar15barrels.com/data/223-556.pdf


SAAMI "warns" us that all military 5.56mm cases are very thick. This is not so. For over 40 years I have weighed the cases for all of my accuracy loads. The thickest us made cases are .223 Federal Gold Medal and American Eagle. Some, if not all, Brit military 5.56mm cases are very thick. Lapua .223 cases are very thick.

Go to Brass Weights:


http://www.ar15barrels.com/tech.shtml


One exception: If your gun has a tight match chamber do not attempt to fire military ball in it.