On my 650 of another popular marque, it’s easy to see that the oil pump is pumping oil towards the crankshaft, by removing the pressure relief valve and turning the engine over a couple of times. Or you can do it before fitting the timing cover. Does that work on a BSA?
That’s all you need to know, to avoid running without oil circulation. You take a look at any oil pressure indicator, light, or gauge, obviously.
Kicking the engine over 500 times, while looking into the oil tank filler is just a bad joke, as far as I’m concerned.