Currently:
H-110 is the same as W-296
HP-38 is the same as W-231
HS-6 is the same as W-540 (discontinued)
H-414 is the same as W-760
However this has not always been the case.
Winchester powder was made by Winchester at thier St. Marks FL facility beginning in 1969.
In 1998, Winchester got out of the powder manufacturing business all together, and St. Marks Powder, Inc. became a seperate company.
In 2006 Winchester divested itself of powder packaging & distrubution.
And Hodgdon took over the packaging & distrubution.
From that point foreward, it all comes out of the same shipping containers and is packaged by Hodgdon.
The powder magazine, packaging, and manufacturing facilities are located in Herington, Kansas. Additional magazine space is located at a closed military air base, (Forbes Field) leased from the City of Topeka, Kansas.
So, if you have older powder, or older data, they were not the same prior to 2006.
rc