A pretty good alloy calculator

http://castboolits.gunloads.com/atta...4&d=1341560870

The "pencil" tests actually are extremely close to an alloy's bhn. I've tested known alloys with pencils and they were spot on. If the pencil scratches into the alloy/bullet, try the next hardness of pencil. You will get to the point where the next harder pencil will not scratch the alloy/bullet. With the GT bullet a B@ pencil should scrath/dig into te bullet. But a B pencil will not.


GT's website says they cast all their bullets with 96/2/2
96% lead
2% tin
2% antimony

The alloy calculator in the above link puts the GT alloy at 11bhn

They came up with the lead calculator in the link above over on the castbollits website.They also came up with the pencil test pictured above.