Differences Between 'Lead' & 'Hard Cast' Bullets

The Differences between 'Lead' Bullets and 'Hard Cast' Bullets

Many gun owners refer to hard cast bullets as 'lead' bullets. In most cases, they do not understand the drastic differences or they would not use such an inaccurate generalization. This generalization is as inaccurate a generalization as referring to all motorized vehicles as Volkswagens.

Hard cast bullets may contain some lead and be grey in color, but that is where the similarities stop. Hard cast bullets can be formulated of numerous alloy mixes (antimony, silver, tin, etc) containing some lead, but the alloys make the bullet much harder than pure lead. Pure lead has a Brinell hardness # of about 4. Most hard cast bullets will have a Brinell hardness # of 11 to 30 and as such are several times harder than lead.

Generally speaking, a properly designed, sized and lubed hard cast bullet will not leave lead alloy deposits in a rifled barrel, but pure lead bullets will almost always foul a barrel to the point of a total loss of accuracy (with very few rounds fired) and perhaps to the point that the barrel will split or worse. ( see my essay on 'Dangerous Pure Lead Cowboy Ammunition' ) I am employing many abstractions here, as there are a number of ways to make a hard cast bullet foul your barrel and make a pure lead bullet not foul, but on the whole, what I have written in this paragraph is accurate.

Depending on certain variables, in many instances and for many uses, hard cast bullets will not deform or 'mushroom' when they impact living mammal tissues, but lead bullets will deform or 'mushroom' at very low impact speeds. Lead bullets will deform and have much less penetration while hard cast bullets will maintain their shape and penetrate deeply however, this requires using sufficiently hard alloy mixes, matched with intended impact speeds on the intended medium.

Hard cast bullets can be alloyed and designed for hunting large and dangerous game where deep penetration is needed - a lead bullet cannot be used this way. I shudder every time a customer refers to our beautiful hard cast hunting bullets as 'lead' bullets. It happens almost daily.

This short essay could not cover all the variables of/and the differences between hard cast and lead bullets - it would take a large book to do that, but hopefully it sheds some light on the on the general/gross differences.