It doesn't matter where you get the wheel wieghts from, they will be of unknown content.
To be perfectly clear. It's not about whether you are getting wheel weights. It's about how they processed them, and whether they used, for example, a large pot on a turkey fryer (poor heat control) or used an electric temperature controlled furnace (excellent heat control) so that you avoid melting the zinc weights into the alloy ( a poor addition to your bullets). And whether they took good care when they did the job.
If you do it yourself, you have only yourself to blame if the zinc gets into the mix, and really, it's not that hard to prevent. But a scrap yard, that may be processing a 45 gallon drum of weights at a time, probably is less careful, than someone that requires zinc free alloy.
Guys casting Keel weights for a sailboat, for instance, would be pretty happy whether there was zinc or not.
Being as piccolig is in Montreal, I'd bet that there are a few places in the area that sell known alloy metals, that are within reach by a short drive. Phone calls are cheap, and dropping $750 on a pile of material that may or may not be what it claims to be, isn't.
As far as the link to Alchemy castings goes, I'd be interested in knowing what their "further discounts" are, for orders over 200 pounds. They may represent a better deal in the end, if you get the alloy you need, delivered.
I know guys sitting on literally tons of lead. It does not take up much space.
Lesse. A 250 grain bullet, 7000 grains per pound = 28 bullets per pound = 280 bullets per 10 pounds or 2800 bullets per 100 pounds.
I figure my stash of wheel weights is gonna last a while, at 37 grains per...
Cheers
trev