Let's start by looking at the base material, lead. Lead is an interesting material, cheap, plentiful, and rather weak in it's base state. Compared to other elements in the periodic table as well as manufactured materials, lead just doesn't stack up, but works great for. Now of coarse the lead the can be strengthened by adding various other materials to the "pot" as well as heat treatment (heat treatment works by aligning molecules such that they aid each other in strength, like building blocks).

     So you can see lead is pretty darn weak compared to other materials, but we use this to our advantage or detriment as long as we are mindful of it's limitations. This article is going to try to bring a little engineering knowledge to the art of bullet performance, so you, as the reader can really maximize performance of an old technology. The big bullet makers have got most of this down already so let's see if we can level the playing field some.

     I assume that you already know the relationship between bullet hardness and barrel leading so it will not be covered here. Jim Taylor's article on leading is a great place to start if more information is needed as well as Lyman's Casting Manual. (Leading Defined)

     Once we get the bullet out of the gun (internal ballistics), and down range (external ballistics) we now need to look at terminal ballistics (where the rubber "meats" the road). Terminal ballistics is what it's all about, making sure that what you shoot at goes down quickly and humanely, nothing is worse than seeing your game limping away to die a slow death. So let's see if I can help you pick the right material so when you have just perfect shot, it counts.

     Let's start by relating velocity (a known quantity) and pressure (which is difficult to measure and quantify). In Duncan MacPherson's book, Bullet Penetration he has calculated and listed a table (Table 7-1) that relates Stagnation Pressure (defined below) with Velocity in water. Water has a very close relation to soft solid materials (like tissue and ordinance gelatin) that makes for a very good replacement, cheap and easy to get.

   From the Fundamental of Fluid Mechanics the definition of stagnation pressure: "stagnation pressure is the largest pressure obtainable along a given streamline. It represents the conversion of all of the kinetic energy into a pressure rise.

     Now let's add one more piece of information, Bullet Composition, I got this information from The Los Angeles Silhouette Club website at: (Cast Bullet Notes)

   So your bullet has a great lube, and a gas check and leaves your bore spotless, but you can't understand why the terminal ballistics are so poor. Look at the table again, are you beyond the capabilities of your lead bullet, either to fast or to slow? Here's the same table in graphic form.

   As you can see, the stagnation pressure and Brinell Hardness are closely related. This relationship is only for objects traveling in a fluid media, and does not take into account solids (i.e. bone). Please note that these velocities and pressures are only seen for a tenth of a millisecond (.0001 seconds) within a fluid before the bullet comes to a stop.

   So what sorts of scenarios can we relate to this data?

• Bullet punches straight through game, (you might want this if you have a large enough caliber and meplat).

• Velocity is low enough to keep the bullet's shape and travel in the intended direction.

• Bullet swerves off it's intended course missing the internal vitals but stays together.

• Velocity is just high enough to deform the nose of the bullet creating an asymmetric shape and unpredictable wound path.

• Bullet drives straight through the target creating a bigger hole on the exit side.

• Velocity is in harmony with the strength of the bullet, expansion was symmetrical allowing the bullet to travel in a straight line.

• Bullet comes completely apart and creates a shallow wound and misses all vitals.

• Velocity was far greater than the bullet strength and was unable to stay together.

So is your bullet weak enough to deform, or is it being pushed to hard to stay together? Are you expecting your cast hollow point to open up? Compare the hardness to the velocity you expect the bullet to be when it reaches the target (which is easy to do with online ballistics calculators). But at the end of the day, this is all analytical exercise, go out and test your bullet and see if it will perform the way you expect. Save those paper mil cartons, set up a row of them at the range and shoot them at the distance you plan on shooting your game.

   Hopefully I've helped you take some of the mystery out of terminal ballistics and how to maximize your bullet's capabilities. Happy hunting, and go get dinner.

   Books I used for reference"

(Mr. MacPherson's book is not the for the faint of heart, it's very similar to many of my college textbooks, but it is considered THE definitive work in modeling handgun bullets. Even John Linebaugh was a bit overwhelmed when he flipped through one of my copies).