Veral,
I notice some outfits sell ammunition that employs water-quenched hard cast bullets that they say are low antimony alloy to avoid shattering. I recall reading somewhere that what makes it possible to water-harden lead alloys is the inclusion of a tiny amount of arsenic, which wheel weights apparently have. My objective is a water-hardened bullet alloy that won't be brittle enough to disintegrate when it hits bone in cold weather.
Of course this raises a half-dozen questions:
(I'll bracket my answers and and put them with your questions to make it easy to follow for anyone reading.)
How low does the antimony percentage in a bullet alloy have to go to avoid cold weather shattering? (The lower the better. So for the coldest weather performance, use just enough antimony to get the hardness needed to obtain desired velocity. For revolver use, just wheel weight metal water quenched will not let you down. For higher velocity rifle use, dilute the WW with half or three quarters lead and oven harden. Optimum hardness for rifle use will be 16 bhn with the very low antimony alloy.)
Can wheelweight alloy bullets shatter hitting bone in cold weather? (Yes, when fired from rifles. I find that 20 bhn bullets turn to powder with very shallow penetration, with impact velocities of about 2600 fps and higher at temperatures below 0 F. Follow above procedure outlined above.)
How much arsenic has to be present for water hardening to work? (A trace and WW alloy has it, and one is probably wise to use it unless they cannot find junk wheel weights. Try scrap metal dealers, and most tire shops have contracts for their scrap weights and won't sell to individuals. Many commercial casting alloys don't. Ask the manufacturer if you want to experiment with their alloy.)
Is the degree of water hardening a factor in the tendency to shatter in cold weather (BHN 20, 25, 30, 35)? (Yes, along with speed. i.e. If the hardness is high enough to eliminate deformation at the speed of interest, it will not shatter except on impact with very large bones. I believe my book will inform you quite well on the particulars. But you can test on water filled one gallon plastic jugs, shot at very close range with gun and ammo at the temperature of interest, and ammo loaded at a bit higher velocity than will be used on the hunt. It the bullet will penetrate a piece of 2X plank placed behind the water jug it will kill game cleanly.)
Does the addition of a couple percent of silver help (I've seen some bullet makers advertise this alloy)? (Trust me. NO MANAFACTURE PUTS EVEN ONE PERCENT SILVER IN THEIR ALLOY! They could not afford to use more than a trace, and only a trace will improve castibility, and make bullets much more shiny, but I cannot detect any other advantage. I melt off about a two inch length of 1/8 inch diameter no lead plumbers solder per 20 lb pot of any alloy I use, just for those two advantages. Most hardwares sell this solder and the very common Trustworthy brand is fine. If not that brand, read the label and be sure it contains silver. The rest will be tin and a small amount of antimony. )
Thanks,
Nick
