Go to www.6mmbr.com
and they have a whole string of articles on the 30 br.
One guy set a 600 yd record with it (caught perfect conditions) but it is not the caliber of choice for 600 and you can flat rule it out for 1000.
If I was looking for a 600-1000, for paper punching would look at the 6br improved such as dasher, BR-dx or BRX. Either 8 twist with the 95-107 VLDs, 10 twist for the 95 Berger VLD, or 9 twist for the BIB 108 FB.