You see it in writing all the time, “hard cast bullets.” This one term confuses and stymies handloaders and shooters alike, but what does it all really mean? Since cast lead bullets are used more for handguns than rifles, we will stick to that arena for now.
Lead hardness is rated on the Brinell Hardness scale, and pure lead has a BHN of 5, making it very soft. For handguns or rifles this would cause leading, which is the smearing of lead inside the barrel and can ruin accuracy very quickly. So a delicate balance must be kept between the appropriate hardness of the lead bullet to do the job you want done without ruining accuracy and causing the dreaded leading in your barrel.
The trend today seems to be to cast bullets as hard as possible, with a BHN around 20, advertised to prevent leading, which unfortunately is not the case as a bullet that is too hard can actually cause the same problem. Where can the truth be found? Well, as with so many things, we must look back to some of the pioneers to see where the solution lies.
The early handgun shooters and hunters described using hard cast bullets for pretty much everything under the sun, from hunting to target practice. Keep in mind this was back in the 1920’s and ‘30’s when there were no real suppliers of jacketed hollowpoints and since money was tight, they cast their own bullets and reloaded their own ammunition in the most primitive of settings. They did not have the expensive casting set ups that are out there now, so when they described hard cast bullets, what they used were really soft compared to what is out there now. Elmer Keith’s own bullets that he used in the .44 Special and later the .44 Magnum were cast with a BHN of about 11, well under what is being sold now commercially.
So what does all this mean to someone casting their own bullets? One of the, if not the, most common materials used to cast bullets are lead wheel weights if and where you can find them. Casting wheel weights straight will give you a bullet that averages around 10-12 on the BHN scale, and if you water quench them you will bump that number to around 15-18 BHN, which is more than adequate for many of the magnum velocities up to around 1,200-1,500 fps. Even air cooled bullets from wheel weights should be safe up to 1,200 fps.
While bullet hardness might be irrelevant for target practice, when your target is a moving and breathing animal, it can make all the difference. In the early days those old time handgun hunters were bringing down game like elk and larger with revolvers prior to the .357 Magnum’s invention in 1935. It was the combination of skill, and the choice of bullets that made all the difference. Elmer Keith had one such memorable elk hunt with a Colt Single Action Army in .38-40 in 1919. Elmer had wounded the elk with a .30-06 and then the bull jumped up and made a lot of trouble for him. Elmer drew on the elk with his Colt after the animal jumped up and knocked him down, losing his rifle in the process. Elmer had the old factory 180 grain lead bullet alternated with his own, and as he said, “The first shot was one of the then new, tinned primer Remington .38-40 soft points. The second was one of my heavy handloads with a 210 grain cast .40-65 Winchester bullet backed by 40 grains of black powder. The first slug had simply splattered out on his skull and not even broken the bone, while the handload had gone back into the jaws, but, as I later found out, too low for the brain.”
Elmer again got knocked down again by the elk after he thought it was dead, he turned loose the .38-40 again striking the elk four more times including breaking its back before parking one of the heavy handloads into the bull’s neck, breaking it and putting it down for good. While it was certainly not the outcome Elmer wanted, it showed remarkable performance for a gun that is the ballistic equivalent of the .40 S & W. Elmer Keith went back to the .45 Colt, then the .44 Special and his use of cast bullets led to the invention of the .44 Magnum.
“Hard” cast bullets really a is subjective science and before you turn that gigantic pile of wheel weights or plumbing solder into little projectiles you need to know where that little BHN number needs to be. Too soft or too hard and you have problems, it is a dark art, but knowing that your hard cast bullets don’t have to be hard enough to penetrate steel will leave you without all that head scratching. Don’t sweat too much over your casting furnace, after all, life it too hard but your bullets don’t have to be.