Don't "read" Pressure signs in brass. Watch the chronograph.
I don't think so. Forget the chronograph. It's only an indirect measure of pressure and a bit crude at that. There was a gun purveyor who had 10 "identical" rifles in which he shot the same load. Velocities between the rifles varied by as much as 200 fps.
Pressure signs are going to vary depending on the cartridge and the gun. With a 223 cartridge, there probably isn't going to be much primer flattening or even sticky extraction in a bolt gun. What will probably happen first is a primer leak or a pierced primer.
What I've found useful, if you're shooting an accurate gun that is, is to look at group size. As you start low and work up, groups will generally get smaller up to a point and will then start to open up again; sometimes with a marked POI shift. I stop where the groups are the smallest.
