It's been my experience that using magnum primers would not have rescued this ^^ assemblage.
I gave up on HS-6 with both 38 & 44 Special. There just isn't enough pressure and the internal case volume is just too large to get it to clean up and run consistently. I suppose if I used a 158gn jacketed bullet, tightly roll crimped, mag primers, and loaded beyond +p, they'd probably clean up. But I have no desire to run such a round.
HS-6 likes pressure and the tight confines of semi-auto cartridges. Plain n simple.
357 is cavernous, but you can pump it up with enough pressure to get it to clean up. No such pressure with 38 Special; so the result is an unbalanced, poorly performing round.