The theory as I understand it is that faster burning powders would tend to build up pressure behind the bullet more quickly, pushing the edges of the bullet base up into the bore and kind of sealing up the back end. Slower powders would build pressure more slowly, which ought to allow more gas to leak around the unsealed base before/if pressure reaches a point where it can deform the base of the bullet, or obturate it, so that it seals up. Faster powders and softer bullets would be better for that, as would a flat base be better than a bevel base, and a slightly oversized bullet would be better than a slightly undersize bullet.
You could try loading a few up with a faster pistol powder, if you have it. If there's a silver lining with leading with 45ACP, it's that the rifling is much shallower than with 9mm or 40, so it's easier to scub out leading with 45 than with other chamberings.