... was due to obvious pressure ...
There is a common mis-perception that pressure signs are obvious. They are not.
There are different indications of pressure, none of them can be measured by eye.
By the time you see the physical manifestation of pressure, you are already damaging the hardware and components. Bolt setback. Stretched web area. Brass stuck to the chamber walls.
Measure everything, or it's heresay. If you think the primer pockets are loose, measure them, and compare to new brass. That's the only way to figure out if the pocket loosened up, or if it was a factory defect to begin with. How the seating feels is not a measure of primer pocket size.
A lot of reloaders quote the physical indicators, such as popped primers or a stuck bolt, to describe their pressure or lack thereof. Looking at the primers after firing tells you if the primer cup was harder or softer. A soft primer will spread itself flatter than a hard primer. Neither is a pressure measurement. Saying that you see no pressure signs is like saying you can't see any gamma radiation from the surface of the sun.
For my rifles, with the primers I use, I see no difference in fired primers when working up a load from the low to high end of the velocity range.
Use a chrony when doing load development, and learn to correctly use the velocity number in the loading manual. The first rule of load development is to ignore any load data that is not verifiable in a powder manual.
I've seen a lot of loose primer pockets, and so far it's never a factory defect, it's always from chasing velocity numbers.
So for the OP, if after two firings you really do have loose primer pockets, my money is not on the brass, it's on too much velocity.
