Cast Lead Bullets
| Field | Shooting Sports, Hunting |
| Went Obsolete | Not Obsolete |
| Made Obsolete By | |
| Knowledge Assumed | Building a fire or using an electric furnace, simple metallurgy, safe reloading procedures |
| When useful | Competition handgun shooting, handloading, black powder firearms |
Far from obsolete, bullet casting is still common in some sectors of the Shooting Sports community. Hand cast, lead alloy bullets can provide exceptional accuracy in modern handguns and rifles. Lyman Products and Lee Precision still produce a large and varied line of bullet moulds for rifles and handguns, as well as bullet casting furnaces, lead dippers and ladles, bullet swagers and lubricators and bullet lubricant. Copper gas checks and half-jackets are readily available to provide a copper seal on the base of the cast bullet to improve the bullet-to-barrel gas seal and help reduce barrel leading. In addition, bullet casting is done by black powder enthusiasts who wish a better product than is commercially available and among owners of some antique firearms (such as the Burnside Carbine from the Civil War) for which bullets of the appropriate caliber are no longer readily available.
Modern bullet moulds are made from either cold-rolled steel blocks or aluminum billets, precisely faced to provide a seal. The mould cavities are cut with specially designed cutters called "cherries" and frequently feature one or more grooves around the base of the bullet into which bullet lubricant is forced when the bullet is swaged (sized) after casting. The bullet design may also include a rebated base to accept a gas check or a hollow base to allow a "skirt" that will expand against the lands and grooves in the barrel to improve the gas seal. Most moulds feature wooden handles and a pivoting sprue cutter that is struck with a hardwood mallet to sever the sprue after casting. Modern moulds may have anywhere from 1 to 6 or more cavities, allowing for increased production rates.
Appropriate data for the use of hand-cast lead bullets in modern cartridges is available from most smokeless powder manufacturers. RCBS still publishes a cast-bullet handbook, as does Lyman Products.
Casting bullets was usually done with a permanent, two part iron mold. The mold would already have all the channels, pouring holes, and vents (gating, sprues, and risers in terminology) needed to properly distribute the molten lead. One would then melt scrap or ingot lead in a cast iron, ceramic, or brass vessel and pour it into the sprue. After a few minutes cooling time, the mold would be tapped on something hard in order to break loose the halves of the mold, and the bullets would be extracted. Those having difficulty breaking the mold open would, in the future, dust the inside of the mold with a lining of ash as a release. After extraction, gating would be cut off the bullets with a blade, such as that of a hunting knife or hatchet. Lead from the gating of one batch could then be re-melted into the next batch of bullet-lead.
Originally, bullets may have been cast in sand or clay at some point, but since lead melts at a scant 600F, it made more sense to use a less labor intensive permanent mold process. Also, materials other than lead were used at various times, but the ease of production of lead bullets, and the punch their high mass gave, lead to their prevalence.
Reference: :The Lyman Cast Bullet Handbook, Third Edition (1992)
Links:
- Lyman Products
- http://www.lymanproducts.com/lymanproducts/casting.htm(approve sites)
- Lee Precision
- http://www.leeprecision.com/cgi/catalog/browse.cgi(approve sites)
- Los Angeles Silhouette Club's Cast Bullet reference page
- http://www.lasc.us/CastBulletNotes.htm(approve sites)
- Montana Bullet Works Cast Bullet FAQ
- http://www.montanabulletworks.com/wst_page9.html(approve sites)