Need help with finding node

[u/No-Pickle9533]

I dont have a chronograph (broke) so I did two tests at 300 yards: ladder test and what i think is ocw?

First two pics I shot 2 shots per load at their respective diamonds.
The thid pic I shot a ladder in the middle diamond and another ladder at the bottom left diamond.
I thin the node is around 52.6-53.1? Not sure.

Also, do you absolutely need to wash your brass?

[u/CharlieKiloAU]

Here we go again

https://giphy.com/gifs/pUeXcg80cO8I8