Thanks for the comments. Been digging around about hardness (BHN) and have collected a little data from many sources.
Common Bullet Alloys
Alloy BHN Specific Gravity
Lead 5 11.34
WW (stick on) 5.3 98% Pb, .25% Antimony, 1.75% trace Ar, Si, Ca, Sn, etc.
85.7% Pb + 14.3% WW 6.0 6 to 1 (Pb-WW)
83.3% Pb + 16.7% WW 6.2 5 to 1 (Pb-WW)
80% Pb + 20% WW 6.4 4 to 1 (Pb-WW)
75% Pb + 25% WW 6.75 3 to 1 (Pb-WW)
Tin 7 7.3
50% Pb + 50% Range scraps7 50% Pb, 50% Range scraps
70% Pb + 30% WW 7.1 7 to 3 (Pb-WW)
60% Pb + 40% WW 7.8 6 to 4 (Pb-WW)
1 to 40 (Sn-Pb) 8 (8.5) 97.5% Pb, 2.5% Sn
Range scraps 8-10 98.1% Pb, 1.9% Antimony, .1-.2% tin
1 to 30 (Sn-Pb) 8.5-9 97% Pb, 3% Sn
½ Pb + ½ WW 9 for 45acp & 38sp
6 lb Pb + ½ lb 50/50 solder 9
1 to 24 (Sn-Pb) 9.6 95.8% Pb, 4.2% Sn
1 to 20 (Sn-Pb) 10 95% Pb, 5% Sn original alloy used in early bullets 11.0
1 to 16 (Sn-Pb) 11 94% Pb, 6% Sn
50% Lyman #2+ 50% Pb 11
1 to 10 (Sn-Pb) 11.5 91% Pb, 9% Sn 10.5
WW (clip on) 12 95.25% Pb, .5% Sn, 4% antimony, .025% arsenic 11.01
Electrotype 12 94.5% Pb, 3.0% Sn, 2.5%antimony
75% WW + 25% linotype 12.5 93.1% Pb, 1.1% Sn, 5.8% antimony
Lead shot 13 .5-1.0% arsenic, hardens when heat treated; ¼ of 1% arsenic.
80% WW + 20% stereotype14.5 92.4% Pb, 1.6% Sn, 6.0% antimony
Lyman #2 15 90% Pb, 5% Sn, 5% antimony 10.683
Taracorp Magnum 15 92% Pb, 2% Sn, 6% antimony (common in commercial lead bullets)
50% Pb + 50% Linotype 15 50% Pb+50% Linotype
Water quench ½Pb +½ WW18 some BHN variation
50% Pb + 50% Monotype 20 mix 50/50 with pure lead (for rifle)
Linotype 21 4% Pb, 4% Sn, 12% antimony 10.4
Water quenched WW 22 some BHN variation
Stereotype 23 80% Pb, 6% Sn, 14% antimony 11.3
Monotype 28 72% PB, 9% Sn, 19% antimony
Oven treated WW 30-32 heat treating with arsenic present to about 30 to 32 BHN
Foundry 32 62% Pb, 15% Sn, 23% antimony
Antimony 50 6.68
Is there a minimum chamber pressure for lead alloys?
A formula (from the pages of HandLoader Magazine) to determine at what pressure an alloy of given BHN will obdurate the base of the bullet and seal the bore. If the bullet is too hard to obdurate, gas cutting usually occurs on the base band on the non-driving side of the rifling and barrel leading is likely. Simply multiply the alloy BHN by 1,422.
Example: Alloy BHN of 12 multiplied by 1422 = 17,064. An alloy of 12 BHN should be used with a load that develops a "minimum" of 17,000 psi. Need more info on minimum / maximum alloy BHN?
BUT I don't shoot "proof loads"; so much softer is appropriate: 5 to 7 BHN (?)
Conicals could be harder as lube grooves are design enable easier deformation and filling the grooves. So maybe BHN 6 to 9 or 10?
Part of this is thinking about available alloy and cost of components.
What do you think? Anybody know about psi in Cap & Ball pistols in normal loads? Or where to look?
Regards,
R. Flux