Casting rounds with unknow alloy make a slightly different diameter. The antimony in WW makes the ball larger and harder.
Harder = Harder to load .
Maybe..., maybe not...while the alloyed lead does not shrink as much as all lead, whether or not the ball is harder to load is based on the patching material and thickness. Now if you're casting conicals like Maxi-balls, or Lee REAL bullets, you might just end up with something you can't load.
Consider this: in the 19th century, canned goods (foodstuffs) were sealed with lead solder. During the Civil War, things like canned peaches were considered luxury goods and were the province of high-ranking officers. Historians now think that some inexplicably bad command decisions during the war can be attributed to chronic lead poisoning on the part of those in command. Same with the Franklin Expedition to find the Northwest Passage, in 1845.
Well those "historians" might want to look at the science involved. The Franklin expedition was heating up the food
IN the cans directly over the flame thus getting much more lead transfer.., canned peaches in those days were only boil-canned, not even pressure canned, and while there was some lead transferred, you'd need to be eating peaches at every meal for quite some time (or for some reason heating them up over the fire) before building up enough lead from that source....
Couple of those, cleaned up and with mixed with two handfuls of wheel weights,nets me about 300-500 balls for the .50. The rest gets turned into river sinkers for when chasing blues and flatheads.
YES you can use a "sinker alloy" for casting lead bullets, and as I mentioned above, if they are round ball they don't shrink as much when cooling, so you may need to adjust your patches IF you go from all lead to an alloy using a patched, round ball. IF you've been using the alloy from the beginning, you're fine.
Alloyed lead, such as you're making, or wheel weights, or linotype, or if you harvest modern lead bullets from the berm at your local range, give you an advantage..., they will not deform, or deform much less, upon impact with a big game animal, which should give you deeper penetration. Being just a tad lighter than all lead they will give you a few more feet per second in muzzle velocity. Not really anything significant, but the higher speed is there. NOW IF you are shooting a smoothbore, especially if you don't patch the ball..., there's probably no change that you will see at all.
All lead gives you a nice soft projectile that will deform on impact, and normally this increases your wound potential. It must be balanced when going after the really large cervids such as Elk or Moose. Too much deformation at nearly max range and one's ball might actually retard it's path to the point of not doing as much damage as needed.
"It is evident that, of two wounds of equal depth, that which has the larger area will have the most effect on the internal economy of the animal. It will rupture more blood-vessels and nerves in proportion as it is larger than the other, and so produce more sudden blood letting and shock to the [animal's]
system. It may, moreover, include a bone or vital organ, such as heart or brain, in its path, which would not be included in the narrower wound, and in practice this will frequently be found to be the case. Penetration, therefore, being equal, or sufficient, in both cases, that projectile which has the largest striking surface is the best for our purpose." Capt. J. Forsyth
The Sporting Rifle and Its Projectiles (1867)
So in this quote from a century and a half ago, from a fellow who was hunting large and dangerous game up to and including elephants, even then concluded by direct observation that a larger diameter round ball was better (yes even better than lead conicals), IF it went deep enough, or better yet passed through.
LD