Honestly...it doesn't really make that huge a difference. Good old "regular" even less expensive commercially loaded brass cased stuff works just fine in SBRs.
My SBR (a BCM with Surefire suppressor) runs all day long on the stuff and with a red dot optic, I can routinely get kill zone shots on torso sized targets out to 150 to 200 yards (no doubt further, but I have no drilled with it beyond 200 yards to comment).