Editing Transitional ballistics (section)

==The transitional period==
Transitional ballistics is a complex field that involves a number of variables that are not fully understood; therefore, it is not an [[exact science]].<ref name="carlucci">{{cite book
|last=Carlucci
|first=Donald E
|author2=Sidney S. Jacobson
 |title=Ballistics: Theory and Design of Guns and Ammunition
|year=2007
|publisher=[[CRC Press]]
|isbn= 978-1-4200-6618-0
|page=3
}}</ref> When the bullet reaches the muzzle of the barrel, the escaping gases are still, in many cases, at hundreds of atmospheres of pressure.<ref name=":0" /> Once the bullet exits the barrel, breaking the seal, the gases are free to move past the bullet and expand in all directions. 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.<ref name=":1" />

The propellant gases continue to exert force on the bullet and firearm for a short while after the bullet leaves the barrel. One of the essential elements of [[accurizing]] a firearm is to make sure that this force does not disrupt the bullet from its path. 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 [[normal distribution|Gaussian]] pattern.{{Citation needed|date=September 2020}}

Most firearms have muzzle velocities in excess of the ambient [[speed of sound]], and even in [[Speed of sound|subsonic]] cartridges the escaping gases will exceed the speed of sound, forming a [[shock wave]]. This wave will quickly slow as the expanding gas cools, dropping the speed of sound within the expanding gas, but at close range this shockwave can be very damaging. The muzzle blast from a high powered cartridge can literally shred soft objects in its vicinity, as careless [[benchrest shooting|benchrest pistol shooters]] occasionally find out when the muzzle slips back onto their sandbag and the muzzle blast sends sand flying.{{Citation needed|date=September 2020}}