It was about 10 years ago, I got a 5 gallon bucket nearly full of roll solder, some was lead-free, most was 63-37 or 60-40. Most was flux core. After I schmelted the first batch that was unknown due to missing labels or loose (off the reel/roll), I decided it wasn't worth the hassle of dealing with the Flux sticking to pot side and smoking, smell was nasty, worse that any solder I've used in the past ...and I couldn't get it to burn up. So I kept some rolls for use as solder, and sold the rest to fellow casters. I have plenty of other tin in my scrap metals stash to use for bullet casting alloys.