You mentioned that the 125gr HST performed better than the 125gr GD. I'm not surprised. Can you provide additional details and/or pictures?
I no longer have the slugs for pictures. The HST exhibited more energy throught the first two jugs. The GD folded in on itself to a smaller, rounder mushroom than the HST. Besides expanding more, the HST had a jagged edged around the circumference of the mushroom. I do not know if this sounds right, but the HST seemed to be designed for its velocity, or to perform exactly the same at a veloctiy range. I have found GD performance in the 357 sig bullet to be velocity dependent. Also as mentioned in my post below, the HST actually tore a large hole (read plastic missing) on the exit of the first jug and not the stretch tear I have seen with GD's