I had an identical mould many years ago that I bought for a 357 Max Contender I had. My particular combination worked best with the bullet seated in the lower crimp groove to compensate the stupid long throat my Contender had. It also shot best when loaded really hot. Other uses included loading the same bullet in 38 Spl cases with around 3.5 grains of 700X for bowling pins. The pins were impressed by that load.
TC barrels in the old days never shot that well for me with cast. I know a bit more about cast bullet performance now, and suspect that my barrel may have been a bit oversized, and that I should have tried softer alloys than lino to get better accuracy. That particular combination never shot well enough to even consider shooting silhouette with it. My best accuracy actually came from Hornady 35 cal. Single-Shot Pistol Bullets, and even that wasn't great. And the next silhouette season was the last one for me. The range I shot long range at ceased all long-range handgun events after that season, and the next closest range was almost a four hour drive each way.Wonder if the bullets length was at the edge for your twist and that's why it shot better hot?