[Morley]

If you have ever looked at a "real" oil priming tool, you'll remember seeing what looked like a large thread spool that moved up and down the shaft freely. That "spool" slides dpwn the shaft when you put the tool in the engine and blocks the back of the oil galleys and it looks just about like the large machined area at the bottom of the distributor's housing. It blocks the back end of the galleys so pressure will build in the oil galleys.
Just using the oil pump shaft isn't sending oil to everywhere it needs to go. See if your auto parts store has a priming tool you can borrow/rent.