Zinc bullets

[85MikeTPI]

I’ve been following along some groups that talk about casting with zinc. I have everything ready to cast some zinc 12ga slugs, but the weather and timing haven’t worked out so far this Fall/Winter.

Anyone else cast with zinc before ?

This was posted this morning in one of the groups too



I have two 5gal buckets of zinc wheel weights that I started saving last year instead of throwing them out sorting lead.

 

[Blacksmith101]

Cast Boolits Forum

Zinc Casted Bullets​

Zinc Casted Bullets

What are people's opinions on Zinc bullets? While pure lead typically has a Brinell hardness number (BHN) ranging from 5 to 15, pure zinc registers at 30 BHN. Even Zamak 3 boasts a BHN of 80. Some have expressed concerns that Zinc may be too abrasive on barrels. However, solid copper bullets...

castboolits.gunloads.com

Casting ZINC bullets is tedious​

Casting ZINC bullets is tedious

Zinc is no fun to cast with. I just made a couple of handfuls of ZINC Noe 225 grain 30 cal blackout bullets. First I had to render the ZN wheel weights -this took hours. I take the ZN wheel weights and put them in a cast iron pot then scoop out the clips which irritatingly end up at the bottom...

castboolits.gunloads.com

What to do with zinc ingots? see post #19​

What to do with zinc ingots?

Being a scrounger, I hate to waste anything. The other day I melted down the zinc WWs I have been setting aside. It was difficult to get enough heat to melt them with my setup. That was reassuring to make sure I didn't melt any accidentally with the rest of my WWs. I made muffin ingots out of...

castboolits.gunloads.com

 

[JohnnyE]

The answer is 3%.

 

[85MikeTPI]

Cast Boolits Forum

Zinc Casted Bullets​

Zinc Casted Bullets

What are people's opinions on Zinc bullets? While pure lead typically has a Brinell hardness number (BHN) ranging from 5 to 15, pure zinc registers at 30 BHN. Even Zamak 3 boasts a BHN of 80. Some have expressed concerns that Zinc may be too abrasive on barrels. However, solid copper bullets...

castboolits.gunloads.com

Casting ZINC bullets is tedious​

Casting ZINC bullets is tedious

Zinc is no fun to cast with. I just made a couple of handfuls of ZINC Noe 225 grain 30 cal blackout bullets. First I had to render the ZN wheel weights -this took hours. I take the ZN wheel weights and put them in a cast iron pot then scoop out the clips which irritatingly end up at the bottom...

castboolits.gunloads.com

What to do with zinc ingots? see post #19​

What to do with zinc ingots?

Being a scrounger, I hate to waste anything. The other day I melted down the zinc WWs I have been setting aside. It was difficult to get enough heat to melt them with my setup. That was reassuring to make sure I didn't melt any accidentally with the rest of my WWs. I made muffin ingots out of...

castboolits.gunloads.com

Yup, all good info and anyone looking at zinc should be aware of them. From one of the posts:

————
“Here's a suggestion. Do you cast shotgun slugs, perchance? Zinc would be great for that and would punch through a lot of things even a Linotype slug might not. Lee makes a 1 oz (lead, that is) slug mould which is very spherical, so surface tension wouldn't be an issue messing up your cast there.”
———-

I have a cast iron melting pot, a steel Lyman slug mold and iron dipper.

You never know when some legislators might ban lead projectiles

 

[Melnic]

not enough density.

 

[85MikeTPI]

not enough density.

Can you elaborate?

We know zinc is ~63% the weight of lead, are you saying this makes them unable to be used or just you have to know the charge adjusts to the weight?

 

[Melnic]

"bullets" will mean it has to be much longer because of the reduced density for the cartridge that was designed for lead's density. Plus not as soft/maleable to handle the rifling. I can see zinc on the inside like they do armor piercing, but when zinc penetrates more, hmm,

With a bullet density changing, you won't be able to use current tables cause the weight is different or with longer, the case space is different and so goes the pressure differnces.

 

[85MikeTPI]

"bullets" will mean it has to be much longer because of the reduced density for the cartridge that was designed for lead's density. Plus not as soft/maleable to handle the rifling. I can see zinc on the inside like they do armor piercing, but when zinc penetrates more, hmm,

With a bullet density changing, you won't be able to use current tables cause the weight is different or with longer, the case space is different and so goes the pressure differnces.

So everything we got into reloading for

 

[Blacksmith101]

"bullets" will mean it has to be much longer because of the reduced density for the cartridge that was designed for lead's density. Plus not as soft/maleable to handle the rifling. I can see zinc on the inside like they do armor piercing, but when zinc penetrates more, hmm,

With a bullet density changing, you won't be able to use current tables cause the weight is different or with longer, the case space is different and so goes the pressure differnces.

You may have to change the bullet mold design both because of the differences in how zinc vs lead flows to fill the mold. Also the change of density changes the Greenhill Formula as to the length of the projectile in order for any given design to be able to stabilize at a particular rifling twist rate.

Because of the difference in hardness and malleability your obturation to engage the rifling as well as the terminal ballistics expansion and wound cavity, both temporary and permanent, may effect the performance.

Lead density 11.34 g/cm3
Zinc density 7.13 g/cm3

Link to Greenhill Formula

https://www.vcalc.com/wiki/AndrewBudd/Greenhill+Formula+for+Optimal+Rifling+Twist+Rate