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Scharfschuetzer · April 17, 2012, 03:03 PM

Alaska Mike is correct.

When a bullet is too hard for the pressure of the load, it will often fail to obturate (slug up as AM notes) in the bore and it allows some of the gas from the burning powder to gas cut past the base of the bullet and melt or vaporize some of the lead from the circumfrance of the bullet. This is what often the causes leading with hard cast bullets at lower velocities even when the bullets are of the proper diameter.

While it may sound counterintuitive, hard cast bullets are often way too hard for most applications in normal pistol loads. Surprisingly, wheel weight alloy is just about perfect for most applications up to about 1,100 fps. With gas check designs, WW aloy has proven quite good up to about 1700 fps in my rifles. A good lubricant is also helpful in preventing leading. I've never been satisfied with the hard lubes that come on most commercial bullets. I think they use it so that the bullets look good, don't feel so greesy and so that they survive shipment in hot temperatures better. The old NRA alox formula (available from most suppliers) has been my prefered lube for both pistol and rifle cast bullets with smokeless powders.

Approximate Brinell hardness comparisons of lead alloys:

Pure Lead BHN 4

Wheel Weights 12

Lyman #2 BHN 15

Hard Cast BHN 16

Lino Type BHN 21

April 17, 2012, 03:03 PM	#9
Scharfschuetzer Senior Member Join Date: January 28, 2012 Location: Puget Sound Posts: 293	Alaska Mike is correct. When a bullet is too hard for the pressure of the load, it will often fail to obturate (slug up as AM notes) in the bore and it allows some of the gas from the burning powder to gas cut past the base of the bullet and melt or vaporize some of the lead from the circumfrance of the bullet. This is what often the causes leading with hard cast bullets at lower velocities even when the bullets are of the proper diameter. While it may sound counterintuitive, hard cast bullets are often way too hard for most applications in normal pistol loads. Surprisingly, wheel weight alloy is just about perfect for most applications up to about 1,100 fps. With gas check designs, WW aloy has proven quite good up to about 1700 fps in my rifles. A good lubricant is also helpful in preventing leading. I've never been satisfied with the hard lubes that come on most commercial bullets. I think they use it so that the bullets look good, don't feel so greesy and so that they survive shipment in hot temperatures better. The old NRA alox formula (available from most suppliers) has been my prefered lube for both pistol and rifle cast bullets with smokeless powders. Approximate Brinell hardness comparisons of lead alloys: Pure Lead BHN 4 Wheel Weights 12 Lyman #2 BHN 15 Hard Cast BHN 16 Lino Type BHN 21 __________________ Scharfschuetzer US Army Distinguished Rifleman Washington State Distinguished Rifleman NRA Police Distinguished Expert Last edited by Scharfschuetzer; April 17, 2012 at 05:39 PM.