I was still in the Glock World with my plastic comment.
I suspect that you are right about the load/powder, certainly my pick-ups are mostly foreign stuff, I suppose bought because of the price. But I think the point that some pistols are at the ragged edge of problems due to tolerances also may be a good one.
Some one at the same range has a .45 which puts a nasty ding in every case, I suspect his timing is way off.
I have no real reason to load .40 S&W, I have only one pistol in it, and that seldom fired, but I save the brass none the less.

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