Winchester contacted me and they are going to check out these rounds. More to follow...
I don't have it in front of me, but S&W recommends that the Scandium 357s do NOT shoot loads heavier than 125 gr in full house 357 loads. They warn heavier bullets will pull out after several shots just as the OP has shown. Being so lightweight, the inertia is equivalent to using an inertia bullet puller to disassemble loaded ammo. We guys gotta read the instructions!
The imprint on my 340PD says to not use any round UNDER 120-gr. This is on the barrel itself.I don't have it in front of me, but S&W recommends that the Scandium 357s do NOT shoot loads heavier than 125 gr in full house 357 loads. They warn heavier bullets will pull out after several shots just as the OP has shown. Being so lightweight, the inertia is equivalent to using an inertia bullet puller to disassemble loaded ammo. We guys gotta read the instructions!