A few things:
1. I can't test the pistol with *any* ammo right now because S&W told me to send my magazines back to them and they haven't yet sent me any new ones in exchange. (And they told me to do this knowing what ammo I had been using.)
2. There ultimately isn't much point to testing the pistol with light ammo:
a. If it *doesn't* work with lighter ammo, all I've done is spend more money to further demonstrate a problem that I've already documented.
b. If it *does* work with light ammo, what am I supposed to do? Just use light ammo going forward? The bottom line is, a 10mm that won't run full-power 10mm ammo might as well be a .40. It would be unacceptable for S&W to take the position, "This gun isn't defective, you just can't use full-power ammo in it." -- unacceptable unless they marketed it as such, in which case, they wouldn't be able to sell any of them.
Yes, when I get magazines from S&W, I will test the gun with light ammo, because that's the next step that S&W has assigned to me. But, for the reasons explained above, it seems like a way to kick the can a bit further down the road and to foist responsibility for this problem onto me.