Yes, I had heard all sorts of rumors about .40 BOOMs with handloads, including one friend who destroyed
a gun, but I was a bit surprised when my friend, Chief RO and trainer on our security force showed me
a copy of the letter. He said there had been "a couple" in our force, I never went into exact ammo brand,
but the letter clearly stated factory new ammunition. I really think the early chambers were quite 'generous'
and apparently the feed ramp cutout was larger than really prudent.
A whole new product was created to "deGlock" brass which had the base so swollen that it couldn't fit into
other brand .40s with ordinary sizing. As it was explained to me, this is a push through sizer like the Lee
bullet sizer, sizes all the way down the head. IMO, if the head of a factory round is swelling at all, this is
a very bad sign.
Clearly, the overwhelming majority of the time, 99.9999 or something, all is well. But with literally billions
of rounds made and fired, even exceptionally rare events happen.
Bill