You can buy a hardness tester etc. but why spend 60 buck and up for something that will tell you the same basic number as I am going to explain. This works great and with the many times that I have tested it with a real BHN meter that my friend has, it is usually right on or 1/2 number lower or higher which is good enough for the bullets we are making. You will need a 1” ball bearing (machine shop) , a set of calipers, 5 pounds of pure lead and a muffin tin from the dollar store ( or splurge at Wal-Mart).
1. Melt the pure lead in one of the muffin tins and let it cool by itself. Once it is cooled mark the pure lead with a black felt maker so you don’t get mixed up.
2. Take your unknown (lead/bullet metal) and do the same thing in another one of the tins. Now prepare this metal as you would your bullet’s i.e. if you drop them on a cloth that has a hole in the middle into a bucket of cold water, or you let them cool on a towel, what ever, do it to this metal.
3. Once both samples are cool take them to a vise.
4. Position the pure lead on one side of the vise and your unknown metal on the other and put the steel ball bearing between them.
5. Squeeze the vise closed no more than about ¼ of the ball bearings diameter; you just want to make a dent into both of the metals.
6. Now take your calipers and with the end of the calipers place it over the hole and measure how deep of an indent the ball bearing made or lay it flat and with a magnifying glass measure the diameter (it is round and the measurement will be the same).
7. Use this formula BHN= 5 x ((diam. Dent in Lead/diam. Dent in sample)^2
So that is 5 times the diam in lead divided by diam in sample squared.
So lets try one.
I took 9 pounds of wheel weights and 1 pound of 50/50 solder and melted it in the pot. Poured it into the muffin tin and let it cool. Squeezed it in the vise with the pure lead and my measurements were this, Lead=.180” and bullet metal was .118"
So plugging it into the formula I have
.180/.118= 1.525 then square it=2.327 then times by 5=11.6 BHN
According to the Lyman manual a 1 to 10 tin-lead mix should be 11.5 BHN
As Shell Busey says “It’s just that easy”.
1. Melt the pure lead in one of the muffin tins and let it cool by itself. Once it is cooled mark the pure lead with a black felt maker so you don’t get mixed up.
2. Take your unknown (lead/bullet metal) and do the same thing in another one of the tins. Now prepare this metal as you would your bullet’s i.e. if you drop them on a cloth that has a hole in the middle into a bucket of cold water, or you let them cool on a towel, what ever, do it to this metal.
3. Once both samples are cool take them to a vise.
4. Position the pure lead on one side of the vise and your unknown metal on the other and put the steel ball bearing between them.
5. Squeeze the vise closed no more than about ¼ of the ball bearings diameter; you just want to make a dent into both of the metals.
6. Now take your calipers and with the end of the calipers place it over the hole and measure how deep of an indent the ball bearing made or lay it flat and with a magnifying glass measure the diameter (it is round and the measurement will be the same).
7. Use this formula BHN= 5 x ((diam. Dent in Lead/diam. Dent in sample)^2
So that is 5 times the diam in lead divided by diam in sample squared.
So lets try one.
I took 9 pounds of wheel weights and 1 pound of 50/50 solder and melted it in the pot. Poured it into the muffin tin and let it cool. Squeezed it in the vise with the pure lead and my measurements were this, Lead=.180” and bullet metal was .118"
So plugging it into the formula I have
.180/.118= 1.525 then square it=2.327 then times by 5=11.6 BHN
According to the Lyman manual a 1 to 10 tin-lead mix should be 11.5 BHN
As Shell Busey says “It’s just that easy”.
