I like to shoot a .223 rem bolt at 100 yards for accuracy. I use any case, new, range or otherwise, well prepared, including deburring flashhole (which subbed another .25 moa from my groups).
I can shoot sub moa all day with the average being under .6 moa. When I feel like getting really tight groups then I sort and weigh cases, only use fireformed neck sized brass etc. With the right gun and the right shooter, anything is possible with the brass, you just have to have the skills and be willing to put the time in.
For every bit of data there is to collect, there is at least someone anal enough to have put in the time to have gathered it at some point.
Guns don't kill people, fathers with pretty daughters do.
Two wrongs don't make a right, but three comes pretty close.
Proud NRA member