I respectfully disagree with the comments about W231 being not appropriate for 147 grain bullets. A while back there was a poster with the User name "Jim Watson" that said the 1993 Hodgdon manual listed a load for W231 (same as HP38, check the load data from Hodgdon if you don't believe us) with a Winchester 147 grain bullet. The bullet material was unspecified. The starting load was 4.0 gr and the max was 4.3 gr.
I used this data to work up a competition load for my son. The gun is a Glock 34. We are using Berry's 147 gr plated bullets, with a charge of 4.0 gr of W231. The OAL is 1.135", but we didn't find any big velocity difference between 1.125 and 1.135" OAL. Average speed of 10 shots in 957 fps.
There are several of us in the competion world that prescribe to the "heavy bullet, fast powder" school of though to reduce felt recoil (for making power factor), which allows a faster follow-up shot. Please, don't take my word for it, check out any of the other forums, Especially Brian Enos.
Hope this helps,
Chris