I saw this same question was asked a while back. Crickets...
I'm a little surprised the 338 Norma hasn't received a little more acceptance than it has. Virtually no lab tested load data out there. Norma has a little but their information is so limited, it's almost useless. I can't even find a "case trim length" spec. I contacted Ramshot about load data. They said they were in the process of developing it but I don't think they need to develop load data to encourage people to buy their products right now so there's no hurry.
Yes I know, I did not look on the Hide.They have alot on the Norma.I got mine in '10 and shoot the 300, but they seem on back order everywhere and I GOT SOME 250 by mistake and thought I would just shoot them or have a lighter speed goat bullet I was ata the range when a guy was testing the 250's out of a trg when they first came out and he had some good groups.There are alot more Normas out there now and Desert Tact. makes a bull pup in the norma