Harmonic balance. Thats why hand loading works so well. You can tune the balance.


This explains it better than I could. https://www.shootingsoftware.com/barrel.htm

shortest answer I can give:

The end of your barrel moves up and down in something that approximates a Sine curve during firing:



you want the bullet to exist the barrel at a peak so that you're not inducing an additional force vector on the bullet, not on the way up or down. You get to that peak by tweaking the amount of powder and the COAL (jump/jam) of the loaded round.

Dan, you want the bullet to exit when the speed of motion is at a minimum, which is at the maximum and minimum values of deflection. Where you cross the x-axis, the speed of motion is maximum.

In fact, some say that you want the bullet to exit the muzzle as it is approaching the very top of the peak. The theory is that if your lowest velocity round (taking shot-to-shot variations into account) exits just as the muzzle reaches the top of its vibration pattern, then the other shots which are higher velocity will exit a tad bit sooner BEFORE the muzzle is at its zenith. This helps compensate for the minute differences in trajectory due to velocity differences. Benchresters have told me that when the rifle is tuned properly this results in minimal vertical spread at a particular range---but ONLY at that range. If the rifle's tuned up for 100 yards, then it won't shoot well at 200.

^^^^ plus little fellows known as gremlins that attack barrels and bullets and powders and burning rates even to the point of how much the ammo has been transported. And don't forget good lady Mother Nature with temps and humidity and pressure of her own.

Your explanation has me a liitle confused. Would not the points at which the waveform crosses the zero axis be the point where you want the bullet to exit the barrel. Whatever the case, the diagram explains how barrel length and makeup, as well as other factors that impact bullet velocity (powder charge, bullet weight, rifling twist, and even the burn rate of the powder) all play a role.

Still, the most accurate rifle in the world, from a design perspective, is no more accurate than the capabilities of the one pulling the trigger. It's a fact wasted on those who somehow believe that even though they seldom practice, they are as accurate as their rifle.

Other than rate-of-twist and the way the freebore is cut, generally NO. Ammo is designed to function well (hopefully) in guns the way they are made, not the other way around.