Re: Norma 217 & 264 Win Mag
This is what I do when looking to find a load for either a cartridge or powder that doesn't have published data. Look for ratios, if in other similar cases, powder charges are x% higher than powder b, and I'm looking for powder b, I have a starting point. Essentially it's cross referencing. Then I back it up with QL.
I've done this with Dakota cases and Berger bullets, and Norma MRP and common cases. For example, 7828ssc and MRP have very close charge weights. This has worked well for me. Start low and work up, like always.