One of the things I like about my Russian slug mold (clone of the Lyman 525 slug) is that it comes with multiple core pins so you can make slugs of varying weight, all the way down to just over 1 oz. So, I can make lighter versions of these very accurate diabolo-shaped slugs. Still requires a bit of tinkering to find the right combo of alloy/wad/load for really good accuracy, but all of the sizes are still better than either size Lee slug or .690 RB.