.223 or 5.56 brass for reloading an AR?

[mario]

I just picked up a Dillon 550 and plan on reloading ammo for my AR-15's. Can I reload the commercial .223 once fired brass or would I be better off just letting it lay where it falls?

[dhhardw]

It's perfectly good brass.  If I bring 100 rounds to the range, I take 100 empties home.  They might not all be mine, but I want to make sure to keep enough brass around to reload.

I have reloaded mil 5.56 cases and commecial .223 Rem cases.  They will save you a lot of money.

David

[bowhunthard]

The main difference between 5.56 and .223 ammo is not the external dimensions, but rather the internal.  For example the thickness of the case walls affect the pressure.  The 5.56 has a smaller internal dimension, therefore the pressure is higher.

So either one will work, just don't load a hot .223 load in a 5.56 casing, it might not be pretty.  I recommend using the appropriate loading data for the case you are using.

Good luck.

[Dragonheart]

For normal loading data either case is fine.  The military cases are a little harder and will have a crimped primer pocket, which will deprime with no problem, but will present problems when re-priming the case.  There are several tools on the market to swage the primer pocket to remove this crimp.  Years ago long before the swage tools and there was a Dillon Precision, I would ream the primer pockets by hand using a reaming tool.  Now I use the Dillon swage tool for this purpose, but it is pricey like everything made by Dillon.