Mike,
The load you 've been shooting is an excellent one, sounds like you're getting optimum accuracy out of it.
The .44-265g WFN and .44-300g WFN that we offer share the same nose to crimp lenth and nose profile, so they too will function flawlessly through your 96/44 Ruger.
I really don't know what you would accomplish using either of them instead of the 280g WFNGC that you are already shooting. Within the range limitations of the .44 Mag cartridge, you might well already have the perfect combination of weight to velocity with what you are shooting. It will certainly handle anything in the lower 48 that you care to take with it!
Have you chronographed that load out of your carbine?
God Bless,
Marshall