A great load in one of my 700 .243 Remingtons is 39.1 grains of Varget behind a 70 Sierra Blitzking. It's nowhere near maxed out but is stunningly accurate.
With a 58 Vmax it's up at 42.0, again no signs of pressure but stunning groups.
Primers falling apart when pressed out should be no cause for concern. Stiff bolt handle, marks on from the bolt face, craters on the primers would all cause me to put the brakes on any load.
Published loads are a carp shoot. My latest pet project .243 LBC (aka 6mm AR) is showing me that it can't handle anything like published max loads.