I shoot a lot of 148 gr HBWCs. Historically, I load over a small charge of Bullseye, but I just loaded a batch with W231. I haven't shot them yet, but I expect them to be pretty accurate.

I seat just below flush and apply a mild crimp.

Your seating and crimping options will have a lot to do with the design of your bullet. Are these double ended, hollow base, or something else? Is there a crimp groove?

I have never had a leading problem with HBWCs, so I typically use soft swaged. I have used coated (Bear Creek) only because they are available at several LGSs near me.