I think it's time to do some careful measuring, Ike. Knowing the headspace dimensions of your rifle, sized and fired cartridges and distance to the lands will be a necessary next step for you IMO. A careful analysis of these dimensions will result in a cartridge tailored to your rifle. Trial and error worked surprisingly well for me for many years but I now have the gauges and I'm not afraid to use them.
Good points above about reduced case capacity (and powder charge) for mil brass and taking smaller steps up from a starting load. Flattened primers alone, esp Federal, may not be a bad thing. Sticky bolt lift and other signs would make me back off the powder as well as check seating depth. Some accurate loads will flatten a primer somewhat with no other pressure signs. My latest 30-06 rifle shoots its best groups so far at a point just under where the primers move from what I call mild to moderate flattening. Previous rifle's pet load was over two grains hotter with almost no primer flattening from an accurate max load.
I watch my primers carefully but they can be misleading or at least misunderstood.