Will add that King did uniform flash holes--but apparently never tested whether it made any difference, like a lot of shooters today. More interesting was his observation that the primers didn't make any noticeable difference, as long as it went bang....
If you believe primers doesn't make a difference in load development then you just keep believing all those magazines you read.
I shoot alot and I know for a FACT primers make a huge difference
Don't think that is what he is saying at all, stating what another perosn observed.
Also pretty sure he isn't reading much of his own writing as well.
Then why even post some so called test.
I encourage everybody do your own testing and don't believe half what you read in magazines or internet and come to your own conclusions.
Besides I believe that test was 30 years ago, things have evolved by leaps and bounds today.
