5.56 Nato Reloading Question

[MK75]

I have a very large supply of once fired 5.56 military brass.
I know that 5.56 cases have slightly less case capacity, and I know that I have to remove the crimp, but I haven't been able to find any 5.56 NATO load data. Do I just use 223 rem data instead? I am not trying to do anything crazy or load "hot" or anything. I just want to load bulk ammo on my progressive press that I can take to the range and blast away.
Thank you in advance for your assistance.

[bruceflinch]

My Lyman/47th lists 223 & 5.56 on the same page.
Please note 5.56 ammo does not work well in a 223 chamber.

Since you brought it up. Will resizing 5.56 cases in a 223 die work????
I've only reloading 223 cases.

[Californio]

Barnes has both .223 and 5.56 load data.

I usually Small Base Resize all once fired Mil Surplus brass, machine gun chambers are usually on the large size and you don't

know what fired the case. Seems to work well in the Mini-14.

I use virgin LC brass that is Full Length Resized for the bolt rifle.

[WoodrowShootist]

Alliant published 5.56 loads as well for TAC powder. Once you FL resize its 223. The 5.56 case actually offers more case volume. If you load to 5.56 you are loading hot as its not following saami sub 55000psi its going to load sub 65000psi. No harm in loading it to 223 specs.

[cpatbay]

I have just been using the 223 remington load data.

[the86d]

Do yourself a favor and invest in a chronograph, and check for overpressure signs such as flattened primers, and you will know if you are loading them hotter than you should...

Capacity of the case is more dependent on MFR, not so much on .223 vs. 5.56, I have read numerous times, and the same goes for case thickness.

[BrianRodela]

Start at the low end of the listed loads and work up. In many cases, the higher velocities don't yield better groups and thats what we are all aiming for anyway.

[DarkSoul]

Remember that there is NO SAAMI spec for 5.56, but there is for .233 so most manuals will just list the .223 data. Loadpro lists for both and really the only difference is the peak pressure rating, this is less about the actual cartridge, and more about the chamber.

As long as you load in the .223 range you should be fine, but like everything when you reload, always double or even triple cross reference from a few sources just to be safe.

[Colt562]

I have a very large supply of once fired 5.56 military brass.
I know that 5.56 cases have slightly less case capacity, and I know that I have to remove the crimp, but I haven't been able to find any 5.56 NATO load data. Do I just use 223 rem data instead? I am not trying to do anything crazy or load "hot" or anything. I just want to load bulk ammo on my progressive press that I can take to the range and blast away.
Thank you in advance for your assistance.

I would take a couple cases and see if you can put a primer in it. Some military brass can have the crimp taken out by just depriming it. My winchester white box brass all had military crimp and I didnt have to swage any of it. In fact if I would have swaged or reamed it I could have made the primer pocket to big so the new primer would fall out.

[MK75]

Thank you for all of your posts guys. This has been very informative, and I think I have the information I was looking for.

[ireload]

My Lyman/47th lists 223 & 5.56 on the same page.
Please note 5.56 ammo does not work well in a 223 chamber.

Since you brought it up. Will resizing 5.56 cases in a 223 die work????
I've only reloading 223 cases.

Bruce, yes your 5.56 case will resize in a .223 die.