Check a fired Hornady case capacity for comparison, maybe with water and powder. You are losing almost 10% case capacity with the Starline or you have light water.
In every case I have checked, at least 10 headstamps, I don’t think I have ever had a fired case that would not at least 24 grains of 296. I always use a drop tube.
If that brass is that small, you might consider using something else if you want max velocity, you will need to work up to around 21.5-22 grains for 2350.
It’s all possible you will get more stretch on the second firing, but probably no longer than 1.078”
That capacity that you are getting 22-22.5, would bother me on full power loads, but without having pressure signs yet, I hope it’s a water quality issue in the weighing.
Just go slow and careful like you have been.