RE: Pressure Signs
I'll copy this direct from the Hornady Reloading manual:
SIGNS OF LOADS BECOMING EXCESSIVE:
1An increase in case head expansion as measured by a very accurate micrometer.
2. hard or sticky extraction from the chamber of the firearm.
3. Flattened primers (the rounded edges of the primer are now flattened, filling the gap between the primer and case head.
4. Cratered primers (primer cup material flowing into the firing pin hole)
5. Ejector marks on the case head.
6. Sooty gas leakage around the primer.
7. Enlarged primer pockets-in the worst cases with the primer blown loose.