Correct me if I'm wrong on ZINC

[beezapilot]

I'm getting back into reloading / casting after a very long break. When I was younger we melted anything that would and had very little issue with our boolits- at least none that we noticed. I see quite a few posts on zinc in the forum and would like to make sure that I "got it". Like mom used to tell me- I was first in line when they handed out brains and all I got was the lid of the box.

1- Zinc is going to melt at a much higher temp and will not flow into the molds as well.
2- It can really mess up an aluminum mold
3- Being lighter, it can prove to be inconsistent on trajectory.
4- Being harder and more brittle, mushrooming is going to be limited on high zinc content boolits.

BUT-
1- Can it damage your firearm?

[btroj]

I doubt it will damage the firearm at all. It doesn't cast well and performs poorly on impact, those are the key factors that make it unworkable for our casting needs.
I doubt it would ever "zinc" the bore, it is plenty hard to handle the stresses in the barrel.

[xacex]

Here are some crumbs on the subject.

http://castboolits.gunloads.com/showthread.php?89931-zinc-boolits-range-report

[fredj338]

Not likely to harm the bbl, bronze is certainly harder & is used in some mon metal bullets. Solid copper is probably harder too. The issue is getting it to cast. Not just mold fill out, but in a bottom pour pot, depending on the pour spout size, it may not even flow.

[evan price]

Zinc acts as the opposite of tin. It prevents the lead from flowing. It makes the lead pull away from the mold. It is lighter than lead. It is harder than lead. It can be separated from lead if you smelt in a low temp pot and flux generously. There will be losses of lead with the zinc. Zinc will not damage a gun barrel because it is still no harder than copper or brass (which is an alloy of copper + zinc!) Having a small amount of zinc in your casting lead is not the death sentance but it makes it harder to control the finished alloy in terms of castability. Adding tin can help overcome zinc effects but tin is expensive. Much cheaper to keep zinc out in the first place.
Zinc *will* make you sick if you inhale the fumes from melting it. You get flu-like symptoms and it's miserable. Called zinc metal fume fever. Sick as a dog for a couple days. Why it is important to have good ventilation when welding galvanized metals.