i cast some .54 RB using lead with a BHN of 22 approximate alloy was 90% PB, 2% SN and 8% SB.
i had that alloy for hard casting a .454 to use in a pistol for moose. worked fine for that.
I cast the RB's to use in a ball mill. worked finer than frog hair for that.
last range session i somehow got a hand full of them mixed together with my pure lead balls. being the lazy slob i am i just loaded them as they came to hand.
luckily i had a mallet on my shooting bench and now my short starter has a flat spot on top. had to drop from .018 patch to .011 and even then they were stiff going down the bore.
i noticed a small increase in felt recoil, being a old bony wuss i feel stuff like that.
on target i got a 1 inch decrease in group size.
the .454 bullets i cast with that alloy penetrated through and through both shoulders of a 1100 lb bull moose. recovered one from a small birch that was behind him. if i can find it i will post a picture.
would i recommend using this alloy for a steady diet? No. does it cause the sun to burn out and the stars to stop twinkling if you do use them? nope.
with the millions of variables just in the manufacture of anything, there is plenty of Absolutes spouted that are not absolutes.
jeepers! i am long winded today!