I'm shooting a .338 win mag which has a shorter case head to shoulder length than the .300 win mag so it will interchange with the .300 win or .338 Lapua magazines either one. My max overall length is 3.627 which is 0.020" off the lands but longer than the sammi coal spec. I'm seating long because I'm shooting long VLD type bullets similar to the berger's. Should I get the standard or CIP mags? Thanks guys.
3.645" is about the absolute limit in a non-CIP .338LM AICS mag, but I wouldn't count on it feeding consistently at that length. I load to 3.625" COAL without any problems, so I think you will be OK with your present recipe.