338 Lapua Improved fireform load request

[ohnomrbillk]

I'm putting an Ackley together. Looking for fireform loads.

I have Berger 300gr VLDs, Retumbo, and Lapua cases.

Any suggestions on powder charge?

 

[4xforfun]

Never had a 338 Improved, but MY rule of thumb is on any AI is FF using somewhere near max book using the parent cartridge.