Re: Barrel burners and velocity
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Massoud</div><div class="ubbcode-body">Barrel life is also affected by something called chambrage, which is what people are referring to when they mention an "overbore" cartridge. Chambrage is the relation of the chamber to the bore. Cartridges with a lot of chambrage, like a 6mm-284, create a lot of turbulence in the gases as they flow through the throat, this turbulence wears the throat much faster than normal.
Another important factor in barrel wear is, in essence, inertia. This is when the bullet first engages the projectile, called engraving, the bullet is going from zero rotational momentum to suddenly spinning. This is the reason why gain twist barrels can extend barrel life. However, gain twist barrels are really only practical in projectiles with driving bands. I mean barrels with a lot of gain, not 14 twist to 13 twist. There is actually a formula for determining the optimal gain to smooth out the "torque curve" that is applied to the bullet.
Justin
</div></div>Justin, doesn't the shoulder angle and neck length affect the practical effects of "chambrage"?My understanding is that the combination of shoulder angle and the neck focus the flow of gasses more or less down the barrel, causing some combinations to more quickly erode the throat.