Dumb question, but I'm not sure what you mean by "duplicate". Are the bullets you want to use the same model as the bullets used in the factory cartridges? If so, then just use a Winchester ball powder and primers, make the cartridges the same OAL as factory ammo, and tune your loads over a chronograph to match factory loads. That should get you pretty close, at least when comparing your hand loads with the lot of factory ammo you're trying to duplicate.
A good place to start would be Winchester's web site to check the load data they publish for that bullet. The answer may be there.