Lapua if you are willing to spend that much per case. I am not.
I use military once fireds, with the processing of the primer pocket.
http://www.gibrass.com
"5.56mm NATO Military Once-Fired, recently purchased, mostly LC, some WCC and FC; some
(223) SAWS (M249) brass, mixed dates.
Add $25/M to polish and process primer pocket. Note that this processing
does not size nor trim.
Ttl Qty: 100 1M 5M 10M 25M 50M
$ Cost: $8 69/M 67/M 65/M 64/M 63/M"
So that is $69 +25= $94.00 for a thousand. That is $9.40 per 100
Midway has: Lapua Reloading Brass 223 Remington for
$294.99 for 500, or $590 per 1,000 or
$59 per 100. So, if I reload my once fireds 8 times and then toss them, you will need to reload your Lapua 50 times to break even.
LC do better than most brands
http://www.accurateshooter.com