When I shot the first ELR PRS match in Wyoming I used a slow 6.5x47L because my 300nm didn’t get built in time.
As others have said some bullets do better than others. An example of an excellent bullet that flat out sucks going through transonic is the 168g SMK popular in 308winThis is very interesting. I thought you judged the range of your round by how long you can keep it supersonic. I’m sure a lot of practice and learning goes into shooting past the transsonic range of a round.