Bob, how fast were you pushing these pin loads?
I push my pin loads as hard as I can safely go, so as to knock the pins off the table.....
Berry's advises no faster than 1200, IIRC.
I will agree that oversized bullets=pressure spikes. Hot loads make that worse.
Did you call Berry's on it? I'm sure they would have been very interested in any QC problems they might have had.
I was using their 45 caliber 200 gr HP's, running them at 1075 fps for a 215 power factor.
In pin shooting they did not have a set power factor you had to make but the standard rule of thumb was a 210 power factor to move the pins off a regulation table with authority.
No I did not contact Berry about the bullet problem as I found another source for true jacketed bullets at the same price.
In all fairness to Berry Bullets my experience may have been just a one time thing that slipped by QC but it's still something that all handloaders should be aware of.
If you start seeing pressure spikes and you are using good brass, nothing else changed, then I suggest checking bullet diameters.