445: here's the 270 data out of the Weatherby guide:
130gr Hornady or 140gr Nosler Partition:
73.3gr MRP MV: 3375

154gr Hornady or 150 NP:
68.5 MRP MV: 3245

Hope this helps. jorge

Here's a little something I dredged up from the IMR Smokeless Powder Guide dated 7/97. They only list data for IMR 7828.
.270 Wby with F215 primers, Wby cases, and 26" barrel:
Nosler Partition 130g- 76.0gr@3500fps COL: 3.25"
Hornady BTSP 140g- 73.5gr@3325fps COL: 3.295"
Nosler Partition 150g- 72.0gr@3215fps COL: 3.250"

IMR7828 !!!!!!!