As mentioned, the binary alloy of lead/tin is preferred because it expands more readily at lower impact velocity and retains weight during expansion regardless of a similar BHN. The "hardness" of a cast bullet is almost always measured by BHN but that is only half of the equation. The other half is malleability of the alloy. Any antimony (the element that creates most of the "hardness/higher BHN) results in a more brittle alloy that when it expands has a tendency to slough off the expansion petals or fragment/shatter.
At above 1700 fps muzzle velocity is do use a ternary alloy in my cast HPs (mostly rifle cartridges) of 97/1.5/1.5. That alloy will expand down to 1500 +/- fps impact velocity w/o fragmenting/shattering, if HP'd correctly. However, that is outside the velocity capability of the 44 Magnum in most handguns. Thus I use the binary alloy for use in my revolvers and Contender.