Good points. I have cast bullets from Zinc which has a melting point about 100 C higher than lead, and it was wrought with difficulties, so this slver alloy with a melting temp about 400 C higher will likely be trying to say the least.
There is an outfit in the U.S.A. that sells lead/silver alloy cast bullets, but their name escapes me.
On a slightly different note, I've often thought when making reloads for old WW2 guns it would be cool to replicate the look of the cupro-nickel jacketed bullets but aside from old surplus ammo I've never seen any before
With the price of silver, it may not be worth it unless you have a lot of vampires hanging around.
I haven't seen a bullet jacketed with cupronickel (about 75% copper/25% nickel alloy) in ammunition manufactured after WWII.
It has some strong points, but its downfall was that it causes metal fouling to a greater degree than typical "gilding material" which is about 95% copper and 5% zinc (brass). Incidentally, nickel is drawn to a magnet and hence people mistake these bullets as being steel jacketed.