I'm with everyone else,
If it has the military crimp in place, its once fired.
Annealing doesn't bother a thing, its actually a way to know the brass was formed correctly.
I anneal about all bottle neck brass, removes the stress from crimps/work hardening,
Restores proper neck tension to the case neck in the event you are not going to crimp and want a brand new brass case release of the bullet.
(Mostly bolt rifle guys, nearly all semi-auto shooters will crimp a little to prevent the bullet from getting banged back into the case)
LC is Lake City, MO., just outside Springfield, MO.
Its the largest ammunition plant in the world, small arms, from hand fired weapons up to 20mm rounds are produced there for all branches of the military.
Winchester used to run it, ATK, the same people that own Federal, CCI, ect took over operation, and with the big government (Homeland Security) buy up of over 2 Billion rounds, in 2012 ATK got the government to accept the standard SAAMI specification cases,
So .223 & 5.56 are exactly the same case, save the crimped primer and military cases have sealed primers & bullets for water resistance.
Virtually everything produced in 5.56 NATO from civilian suppliers (not LC) will have a crimped primer now,
Along with a bunch of .223 will have crimped primers.
The line between .223 & 5.56 has been further blurred...
The two billion plus government order has a lot of .223 head stamped ammo out there with crimped primers and crimped bullets, even if you don't want those crimps...
LC 5.56 brass has always been perfectly safe to load for .223 and its just a pain in the butt to remove the crimp so you can reliably install a new primer without it snagging...
There are 'Swaging' tools that push the crimp back (Muscle),
There are nifty cutters that zip the crimp off,
Its up to you what you use.
Its a one time process, once the crimp is gone, you don't have to do it again.
Personally, once fired LC brass is the best deal in .223 shooting in my opinion.
A good set of dies to push the brass back where it belongs,
Remember, most LC brass is pumped through sloppy chambers, so a good resize is a must, and reload with your favorite home roll & have fun!
Some of us go a little farther,
You will need a rock solid press frame to get them back to EXACTLY SAAMI spec,
Anneal the necks, ect.
Plinking ammo is easy, highly accurate ammo cases is a little more work.
There is ZERO difference in the base brass I can detect,
They act/react like every other brass when sized,
And with a PROPER case neck anneal, I can't tell the difference between LC and any of the 'Premium' (read high $$$) brass out there.