I am not having any problems with the primer pockets on this Bertram brass even after numerous shots with my "Hot" load.
What I am getting is a slight "Click" at the top of the bolt lift after four firings. This is not due to the brass base area but seems to be at the neck shoulder junction area.
The base base showed some initial expansion on the first shot of about 0.001" but not much since.
I have found that my Edge dies were not sizing the shoulder quite enough and have made up a sizing process using a bored out .300RUM FLS die to size the shoulder area a bit more and this has solved the issue.
I also used a Lee .338 RUM FLS die and this also worked once I got the die set up right.