Transitional ballistics

[2][3][4][5] Transitional ballistics is a complex field that involves a number of variables that are not fully understood; therefore, it is not an exact science.

This expansion is what gives gunfire its explosive sound (in conjunction with the sonic boom of the projectile), and is often accompanied by a bright flash as the gases combine with the oxygen in the air and finish combusting.

The worst case is a muzzle or muzzle device such as a flash-hider that is cut at a non-square angle, so that one side of the bullet leaves the barrel early; this will cause the gas to escape in an asymmetric pattern, and will push the bullet away from that side, causing shots to form a "string", where the shots cluster along a line rather than forming a normal Gaussian pattern.

[7] In addition to the process of "crowning" a barrel to ensure a clean and accurate exit of the bullet, there are a number of devices that attempt to harness the muzzle blast for various reasons.

Sound suppressors slow the expansion of gases, allowing it to cool and reducing the rate at which it escapes to prevent a shockwave from forming.

[citation needed] A recoil compensator is designed to direct the gases upwards at roughly a right angle to the bore, in essence making it a small rocket that pushes the muzzle downwards, and counters the "flip", or rise of the muzzle caused by the high bore line of most firearms.

A well designed muzzle brake can significantly reduce recoil, turning a rifle that would otherwise be punishing to shoot into a far more tolerable experience.