So far I have been loading Xtreme 148 gr DEWC into 357 cases by working up from 38 +P data. I've reach 4.8 gr and each subsequent increase in powder charge seem to have an improvement in accuracy. I'd like to try a little larger charge and there are no pressure signs but I've been getting bit nervous about a handgun powder in such a small space. However, I was looking through a 2004 Alliant catalog and I found the following load data for the 148 gr LWC using Bullseye powder:

148 gr LWC
5.7 gr Bullseye
Min OAL 1.33"
1,475 fps from 5.6" bbl
34,000 PSI

Obviously that is a maximum load and should be reduced by at least 10% to start. Still even a 10% reduction is 5.1 gr which larger than I have tried so far.

Has anyone here experimented with a load like the above? Is so, how well did it perform?