Working up a load with new brass

[FallAirFever]

So I have a batch of Lapua brass to start loading for my 308 Win. I had a good load for it with other brass.
Do I need to start from scratch with load development or can I just back off a little bit and go from there?

[260 Rem]

I would start with just a tickle less charge weight...assuming that favorite load is not showing pressure.

[Pathfinder76]

Lapua brass has less capacity and you can run into pressure issues if transferring load data from domestic cases. I’d drop the charge a couple of grains to start.

[Dean2]

Originally Posted by chuck

Lapua brass has less capacity and you can run into pressure issues if transferring load data from domestic cases. I’d drop the charge a couple of grains to start.

I agree, Lapua is consistently 2-3 grains less water capacity than Rem or WW, but often close to Federal so depends. I have some 7-08 that was 11 grains less capacity than WW cases, or almost 20%. Holds about the same as most Military cases.

To know for sure, weigh Lapua and existing case, fill each with water, re-weigh, adjust powder charge by the Percentage difference in weight of water.