I found some lead for sale locally.  It is listed as lead with zinc.

 

Is that normal?

Now this is my 2 cents and it's worth less than I'm charging for it, so take it with a grain of salt. Zinc contamination in lead is becoming more popular with most wheel weights going to steel or zinc now. Is the lead you've found already in ingots? A lot of guys don't like to bother with zinc contaminated lead and I was really paranoid about this when I started smelting and pouring my own weights and jigs but at this point, several years later, I feel it's a non issue. If they're wheel weights, just keep your temp around 700 degree's (or lower) in the smelting pot. If theres doubts as to if a weight is zinc I drop it in the pot and see if it floats after a few seconds. If it it floats, it gets skimmed and trashed. The guys that get in trouble with it are the one's that fill a huge pot, set it on the turkey fryer and then forget about it til it's too late, if youre doing small runs, a few pounds at a time and watching, skimming clips and monitoring the temp you'll NEVER run into a problem.

It is already in ingots.

I have a large amount of chilled 7.5 bird shot would that be better for jigs?

Chilled shot contains antimony which makes it harder than regular lead.  It is ok to use but harder to work with.

I ruined a LEE pot with zinc contaminated lead, and the reason is the lead had a high zinc content. What Outlaw86 told you is true but unless the seller knows the percentage of zinc I'd stay away. I found through my own trial and error in almost 20 years of pouring that if the zinc content is over 5% or 6% it isn't worth it.

I emailed Lee Precision, the manufacturer of the Production Pot IV, with a question about using pewter in this pot. The response was that pewter is okay but "Avoid alloys of pewter that have zinc in them. Otherwise you will have multiple holes in your melting pot, and a hot mess." 

I have a Lee Production Pot IV also. I was given some lead from a friend and it had zinc in it. I had to replace the the pot insert because the zinc plugged the down spout.