I used to do all the 'required' stuff, but the more time I spend on this board, the more I began to consider that for the large case sizes many of us are using to reach way out there and kill something big cleanly, much of the messing around with primer pockets and flash holes may not produce anything except just weakening about the most stressed/unsupported part of the case, the case head and perhaps directly furthering casehead expansion. After all, to perform these operations, aren't we removing structural material (however small amount) right where we need it the most? I have felt that my cases have lasted a bit longer and I've gotten a bit more pressure out of them lately when I've not done the BR steps of flashhole deburring and primer pocket uniforming. This might be much more necessary for typically smaller BR type brass? I think the consensus of many on this board is that for the large cases, those two operations may not be helpful. And, as stated above, I wonder how those operations might lead to premature casehead expansion as we remove structural material from the area that theoretically seems to need it most. Maybe I'm all wet here...
I'm fortunate enough to purchase my 300RUM brass from a location where I can paw through the bin and get cases that pass my visual inspection. I look for a round and centered flash hole and check that the manufacturers 'deburring' (seems to be a little chamfer on the inside of the case) on the inside of the case at the flash hole is uniform from case to case...among other things. Usually go through about 200 cases to find 50 that I like...