I've heard about the pictures of Hodgdon and Winchester powders coming from the same drum, but if you ask Hodgdon, or visit their website, the only two crossovers that they claim are truly identical are 540/HS-6 and 571/HS-7. This is a very good reason to own a manual that shows pressure data. If you have one, it will show differences in max load charges and pressures for 231/HP-38 and 296/H-110. Many believe that 760 is H414. The pressure ranges just don't back that up. Primex was the manufacturer for Hodgdon and Winchester powders and although some powders were very similar as far as the "source" powder, they were made to slightly different spec's for each powder company.
Someone mentioned that Ramshot Silhouette = WAP and that is the case. Winchester dropped WAP and Western Powder Co. obtained the rights to sell it as Ramshot Silhouette. All of this can be confirmed and should be, someone thinking that they can use HP-38 in place of 231 and trying to use 231 data could get into trouble.
Ramshot Zip is a very close powder in burn rate to 231, but is much cleaner. Ramshot's data is lackluster, but if you have a manual that gives data for Zip, it's worth a look!