hard skin on battery terminals

[jbu]

this is my 2nd post and a question. u know the hard skin that forms on battery trminals. well i,m trying to dupicate that on cast lead bullets. i have been

soaking them in new battery acid and it kinda works, but it's not as hard

as the battery terminals. i would likw to speed up the process. maybe heat

needed, differant acid?? in my research, some plateing companys use

lead lined vats and the lead reacts with the acids and forms a skin and protects

itself. i do a lot of target shooting and bullets are expensive, so i cast my own.

i have 8 yrs pulp mill maintainance, clorine, caustic, clorates, and i make my own hot blueing salts from caustic soda and potasium nitrate. i hope someone

can help me with this. thanks Louis

Edited April 4, 2010 by jbu
more info on title

[Mr Skeptic]

Bullets are supposed to be slightly soft. Making hard bullets you might explode your gun, have some hot gasses leak around the bullet, and/or cause increased wear on the barrel.

[DrP]

This reminds me of the "Prometheus" pellets you could get for air riffles. They were hard steel, for penetration, with a lead filling for weight and punch. They had a thin plastic sheath to allow the riffling of the barrel to grip and spin it.

[PaulS1950]

The added hardness of a lead sulfate coating will neither endager the gun nor will it cause excessive wear. A small electical charge will speed the process - that is what happens on the battery post and terminals. The voltage drop across the junction is somewhat lower than .5 volts. The sulphuric acid is required to supply the needed sulfer and oxygen is needed.

 

Is the reason for wanting a harder bullet due to barrel leading?

You can use tin, antimony or silver added to the lead to harden the overall alloy. Tin and antimony are the cheapest (duh) and probably available through suppliers of your lead. If you have anyone who has a supply of lino-type you can add that to get your tin and antimony content.

as always when changing any component reduce your loads and work back up incrementally while watching for signs of over-pressure.