H4831 and H4350 have done very well for me with all bullet weights in my 270.
Around 58gr H4831 under a 130 grain Hornady sst, gave just over 3k fps and sub one inch groups at 100yds.
The H4350 topped out @ around 54gr with the same bullet with slightly higher velocity, but the group size opened up to about 1.25".
If the powders you have on hand don't produce the results your looking for, you might try some H1000. I found it gave comparable velocity and accuracy, but had to use absolute max load to achieve it (64 grs. a highly compressed load.). Only good thing is that the 270 can't hold enough H1000 to get you into trouble with pressure with most bullets.
Just do yourself a favor, and work up from a relatively light powder charge. Not just for safety reasons. Some of the most accurate loads i've ever found were fairly close to minimum loads.
Last edited by steve smith; 08-01-2007 at 12:25 AM..
Reason: Bad typing