Forum member and gunsmith Michael Ezell agrees that N320 is a good selection for that .45 ACP. Mike has also identified that WW 231, whilst accurate, produces sparks and a significant flash. Mike writes: “I initial begun applying N320 immediately after my initially night shoot, when taking pictures IDPA/IPSC matches. https://handloadingsupply.com/product/572-winchester-smokeless-powder-1-lb/