Category Archives: Ballistics

Introduction I love to look for physical interpretations of various constants. Sometimes it is impossible to come up with an interpretation, but such is not the case for the ballistic coefficient. This morning I read a very solid piece of … Continue reading →

A projectile with a large ballistic coefficient is less affected by drag than a projectile with a smaller ballistic coefficient. We can use the the ballistic coefficient to compare the effect of drag on different projectiles. A 16-inch projectile goes so much farther than a rifle bullet because the drag on the 16-inch projectile is relatively small compared to its momentum. Ultimately, this is because mass increases by the cube of the projectile dimensions and drag increases by the square of the projectile dimensions. This means that larger projectiles tend to have higher ballistic coefficients and drag has less effect. Continue reading →

I have had several people ask me questions about the Pejsa ballistic model (previous post) and I thought it would be useful to include some additional posts on the topic. In this post, I will discuss how the formula and parameters were determined for the velocity versus range formula for the range of velocities from 1400 feet per second to 4000 feet per second (sorry about the use of US customary units). Continue reading →

Introduction As I mentioned before, I am reading the book "Modern Practical Ballistics" by Pejsa and am finding some interesting material there. I previously duplicated Peja's derivation for a function describing a G7 standard projectile's velocity versus range. This post … Continue reading →

Introduction As mentioned in a previous post, I am reading the book "Modern Practical Ballistics" by Pejsa. I have been working through some of the derivations in the book and they are interesting enough (at least to me) to be … Continue reading →

The ogive has long been used in projectile design because it simple to manufacture. Over the last few thousand years, people have gotten pretty good at making sections of spheres. However, simple to manufacture does not mean minimum drag. The … Continue reading →

Example One: Sierra 308 Caliber, 155 grain, MatchKing. We will first compute the mass for the Sierra MatchKing projectile (tangent ogive) shown in Figure 10. Observe that this projectile has a flattened nose, called a meplat. Because of the meplat, … Continue reading →