Load Data for 5.56 and .223 difference

[jimmyleost]

Hi,

I'm new to the reloading world and have done a lot of research and reading. I have a few different reloading manuals and reloading books. All of the reloading manuals I have have load data for .223. There is no load data for 5.56.

From my understanding, 5.56 brass is thicker than the .223 counterpart. That being said, I will assume that the thicker brass will decrease the total volume of the casing on the inside which will effectively increase internal pressure.

So, my question is, how do I compensate for this extra pressure as to not over load the round?

Thanks!

[mif_slim]

10% and work up. 10 might be too much, but it's better safe then sorry

[JD586]

Speer states something in their manual to the effect the brass they use to work up their loads are the same dimensions/volume as 5.56 brass so their published loads should be safe, make sure your edition says the same before using them of course

[jimmyleost]

Speer states something in their manual to the effect the brass they use to work up their loads are the same dimensions/volume as 5.56 brass so their published loads should be safe, make sure your edition says the same before using them of course

Maybe I should pick up the Speer Reloading book as well :P.

[bcrich]

Put a few cases of 5.56 on your scale then a few 223 and you will find that they are almost the same, some 223 brass is actually heavier. I have only found big differences in 308 brass and 7.62 nato as well as 30'06. I use the same powder charges in mil brass and commercial brass but only for 223/5.56

[Bug Splat]

They are close enough to use the same load data for both. LC brass is a little thicker and can have a bit higher pressure but if you work up a load, as you always should, the Min load data for both 223 and 5.56 of any brass will be safe. Start at the min and work your way up always checking for pressure signs after ever shot. Also take note of the temp while you shoot. Different powders are temp sensitive and a near max load that is safe on a cold day might not be on a hot day.

[SKSer]

I load them both exactly the same and use .223 load data.

[jimmyleost]

Thanks guys! Will work up my loads to see what shoots best anyway!