Blue68f100
Member
While I can’t recall or quote references, In my 45 years of hand loading, reading manuals and various publications on the subject, I’ve always read that reducing a starting load by 5 or even 10% is a safe way to start. Published data of decades ago can be much different than published data of today. It even varies between different manuals for the same caliber.
Perhaps those with more technical knowledge can expand on this.
The Op wants to use components that currently published data is no longer available for. The component has changed, it’s an unknown value now.
Reducing the starting load IMO is a safe start.
That is only done when MAX load is only given. Then you needed to read all the notes on the powder since some were only 3% or none.
I've been loading for 45+ yrs and this is the way it has always been. You apparently got something mixed up.
Now there are times where you start at min and work down. This is done when your are trying to workup a BE load that's soft shooting so you can control the recoil impulse for the follow up shots.