The factory seconds primers are listed as less than .01% low charge. Over the last couple days I've loaded some of my friends factory second primers in 380 acp, 9mm, 38 spl and small primer 45 acp. A few took a little extra pressure to seat but with mixed headstamp brass that is not unusual on my Dillion press. Out of the small number I tested I did have one failure to fire but it worked on the second strike and could have been not fully seated.
I still have a few of the Fiocchi wooden 12,000 round cases and several cases of Federal primers left from before Covid so I'm going to pass on buying any of the factory second primers.