Haven't heard much on Starline brass yet.
I do know people getting 5-9 reloads with Federal brass, but they aren't running the rounds at max loads either.
I think the false promises put out for this round before it came out, has a lot of people chasing velocities that weren't realistic, without over pressuring the rifle and the brass.
That is just my .02c, but as time goes on, more tests and real data will come out for it.
300blk had the same issues in the beginning too