Lead bullet hardness testing

[AJC1]

Lead is a funny creature and how you treat it as well as time has an impact on your testing results. So when casting bullets when and how do you compare your results. Water quenching obviously rapidly hardens your alloy. Do you quench everything and compare those results, air cool and compare those samples. Do you test as soon as cool a day a week or when you get around to it later.

 

[jmorris]

I don’t push my cast bullets very hard, don’t even gas check them, water quench them etc. I suppose if it were important to me I would make a repeatable way to measure them. I spent a lot of time using Rockwell hardness testers that amount to a given weight, a given “indenter” and a dial indicator to measure how much the indenter goes into the surface.



Hard stuff (what I was using it for) uses diamond tipped indenters softer stuff would be rounded ones out of less expensive materials. What I would come up with would just be a way for me to test relative hardness of samples I had on hand.

I generally just go by weight using one mold I set as my “standard” when I started. With it pure lead drops at 240 grains and is soft, silver solder will drop at 211 and is quite hard. Wheel weights drop at 232 and work for most everything I do.

 

[PapaG]

Years ago I did a personal study using linotype, the 311291 bullet and a friend at work in the inspection lab. Hardness went from as cast which I'll call soft even though it was in the teens to harder after heat and quench, to slightly softer after two weeks rest upon which it became stable at low 20s. Numbers may be a little off after sitting in the memory banks since 1982. They shot well out of my 1952 M70 in a few cast bullet postal matches. Velocity IIRC was around 2100.

 

[243winxb]

Water quenching obviously rapidly hardens your alloy.

Test- 45acp. 10 lbs alloy. 1/2 dropped from mold to water. Other half air cooled. Let sit 2 weeks so water treated can harden. Fire at 25 yards , different days for score. Air cooled scored higher. Not the best testing method, just a reason to shoot more.

45acp - Rotometals linotype test. Internet said- Hard alloy lead barrels using target loads. 3.8 Bullseye, 200 gr lswc CAUSE LEADING. Nope. Barrel looked different, cleaned easly with #9. .452" diameter.

Oven heat treated, water cooled 44 mag vs air cooled. Harder bullets better. Less chance of slump or skip. To much work baking bullets. Just add linotype to alloy for air cooled bullets.

Basic- i add 2" of Rotometals linotype to my Lee 10 lb pot for all bullets when using a base metel of wheel weignts/range scrap, 9mm, 38, 357, 45 acp, 44mag. Sized to groove diameter + .0005" to .001" (Old Lyman Manual)

Matching revolver throats has not worked for me, so far. Still going to test it more.

http://www.totalmateria.com/Article...hich,creep properties have great significance.

 

[243winxb]

Oven heat treated, water cooled

The RCBS 2 needs to be washed off after sizing, before bullets go in the oven.

Q: Is there anything I can do to make the bullets harder?

Cast bullets can be heat treated to increase their hardness providing your alloy has 2% or more antimony present. To heat treat your bullets: Cast your bullets in the normal manner, saving several scrap bullets. Size using RCBS 2 Lube. WASH OFF. Place several scrap bullets on a pan in your oven at 450 degrees and increase the temperature until the bullets start to melt or slump. Be sure to use an accurate oven thermometer and a pan that will not be used again for food. Once the bullets start to melt or slump, back off the temperature about 10 degrees and slide in your first batch of good bullets. Leave these in the oven for 1 hour. Remove the bullets from the oven and plunge them into cool water. Allow them to cool thoroughly. When you are ready to lubricate, install a Lyman sizing die .001" larger than the one used to initially size them. This will prevent the sides of the bullets from work-softening from contact with the sizing die. Next apply gas checks if required and lubricate. BULLETS WILL TAKE 2 WEEKS TO FULLY HARDEN. These are now ready for loading.

 

[Fatelvis]

I use a Cabine Tree tester. After using two other methods, I find it more repeatable and easy to use.
http://castingstuff.com/cabinetree_llc___lead_testers.htm