January 04, 2011
The Centuries-Old Rewards Of Loading Cast Bullets.
Cast bullets offer excellent performance and practicality, especially for handloaders
willing to mold their own.
No one knows exactly when lead was first used to make bullets--maybe as far back as 600 or 700 years--but it's been, until relatively recently, the primary constituent of every bullet ever made. When blackpowder was the only propellant, lead's physical characteristics (very malleable, low melting point, and high density) were the exact criteria required to form the perfect bullet. That all changed with the advent of smokeless propellants in the late 19th century.
When blackpowder burns, it generates about as much smoke as energy. Maximum pressures range up to 20,000 psi, and typical bullet velocities do not usually exceed 2,000 fps. Compared to the smokeless propellants, it's very inefficient. Substantially greater pressures and corresponding velocities can be achieved in modern, steel-alloy arms.
There was only one problem with the changeover to smokeless. The up-'til-then perfect lead bullets couldn't accommodate the significantly increased pressure and velocity. A lead bullet's base can melt from the increased energy released. Because the bullet also rotates faster, that can cause it to slip in the rifling and smear the bore with lead. Accuracy is quickly lost, and removing the lead is very difficult.
Of course, the solution was the conventional cup-and-core (jacketed, lead core) bullet construction. This has been the design norm for the past century and a half except, until about 50 years ago, lead bullets continued to be the factory and handloaders' preference for almost all revolver ammunition. Some of us still cast rifle and handgun bullets today, but the practice is not nearly as popular as it was up until the mid-1900s.
When casting bullets, you have to keep the alloy hot enough and flux it often or the bullets will look like these.
When I began to reload, jacketed bullets had replaced lead even in most factory revolver munitions. My friend Fred started reloading several years before me, and he had several Lyman mold blocks to cast semiwadcutters for his handguns. I owned a few Ruger single actions and realized I could save a couple dollars per box by shooting cast bullets, even though JHP bullets only cost a nickel each at the time. Another friend owned a print shop so I could get all of the type metal I needed. Scrap wheelweights from local garages was also a cheap source for bullet material.
A lubricator/sizer tool (Lyman 450 shown here) uses a precision die and punch to round out the slightly oversize cast bullet while filling each groove with lube.
We shared duties during each casting session. After Fred got a good melt going in the SAECO furnace, I added ingots of lead alloy to the pot as needed, fluxed the metal often to keep the tin and antimony in solution, and skimmed impurities from the surface. While he cast (often using two molds alternately), I inspected the shiny, new bullets and returned the sprues and rejects to the pot.
We always cast during the winter, and Fred wore leather gloves, a long sleeve shirt, and pants--and even high-topped, leather boots--to protect himself. We made sure water never got near the lead pot. Water will explosively turn into steam and blow hot molten lead out of the pot all over. I also learned that freshly cast bullets and ones that have cooled look exactly alike. Ouch!
After each casting session, we took turns sizing and lubing the "good" bullets and then split the fruits of our efforts.
Some guns actually prefer cast bullets. The author's Ruger Blackhawk in .44 Special averages sub-2.00-inch groups at 25 yards with cast bullet handloads.
Loading (and shooting) cast bullets is not much different than using jacketed bullets. You have to be more careful flaring the case mouth so that the sharp edge doesn't shave the cast bullet when it's seated. And depending on how hard the alloy is, it's best to keep muzzle velocities under 1,200 fps or so to avoid leading the bore. If the bullets are fitted with gaschecks, you can drive them quite a bit faster, up to 2,000+ fps.
In addition to being more economical, there's another benefit I've discovered when loading cast bullets. When you roll-crimp jacketed bullets, you must first trim each case to the same length within a couple thousandths of an inch. The case mouths can then be uniformly crimped without crushing the ones that are too long or weakly crimping others that are too short.
When you're loading cast bullets, case lengths can vary more (+/- 0.010 inch) because the crimping grooves are more generous and the reduced metal hardness is more forgiving as the case mouth is rolled over. So instead of having to trim your cases almost every time when you use jacketed bullets, you can skip one or even two firings if you're shooting cast bullets.
The table on the next page lists a few of my favorite cast bullet handloads that I've developed over the years. It's tougher to find scrap lead to melt and mix with bar solder these days, so I usually just buy ingots already alloyed for casting bullets.
I hope this missive adequately addresses a truly practical benefit for shooting that only handloaders can enjoy.