Quote Originally Posted by M4 Colt View Post
excuse me for interupting here guys, but don't the dies play a very big role in the reloading process ?? if you have .223 Rem. dies you are making .223 Rem. ammo and on the other hand if you are using 5.56mm dies you are making 5.56mm ammo.

this is one of the reasons so many people get confused about calibers, most/many AR-15 type rifles have stamped on the receiver ".223Rem." , yet on the barrel you will see 5.56mm NATO, and that is why i use 5.56mm NATO dies.
Are you aware that the loaded cartridge dimensions are all but identical between 223 and 5.56?

The difference between 223 and 5.56 is mostly in the MAXIMUM chamber lengths and the throat diameters.
The minimum lengths are basically identical.

ALL ammo loaded to meet 5.56 specs would easily FIT in 223 chambers.