muzzle as possible. Airguns have significantly lower barrel pressure, and therefore are far less affected by barrel harmonics than firearms. Projectile propulsion consistency: In airguns, the inbuilt powerplants themselves provide the propulsive force to the projectile, so tuning the gun alone is usually sufficient for accurizing as long as the projectiles' weights and shapes are uniform. Firearms, however, rely purely on oxidative chemical reaction of the powder within a cartridge to provide propulsive force, and any slight variations in powder load and combustion efficiency will affect the internal ballistics of the gun, even if the projectile weights and shape are the same. This means that in addition to the gun itself, consistent ammunition performance is also extremely critical for accuracy with firearms. While some manufacturers produce match-grade ammunition with smaller tolerances, it is common for shooters of high-precision disciplines to handload and fine-tune their own ammunition. Furthermore, the rapid gas expansion that occurs when the projectile leaves the muzzle also barometrically affects flight behaviour, so muzzle devices such as flash hider and suppressor can also be used to modulate the escaping gas and improve the consistency of shots. The key to an accurate firearm is consistency. Getting everything to happen the same way for every shot is key to producing small groupings, and there are a large number of issues to be addressed in achieving an accurate firearm. The keys to firing an accurate shot are a firm but not overtight grip, the ability to get a good sight picture and a controlled squeeze of the trigger. The ability to manage recoil is also important in heavily recoiling calibers, both to aid in possible additional shots, and to prevent the user from developing a fear of the recoil. Determining accuracy Determining accuracy is not always a straightforward task, as it depends on a large number of variables. Factors affecting accuracy The accuracy of a shot relies on many different factors, which can be broken down into three broad categories: the firearm, the cartridge, and the shooter. Accurizing generally refers to the processes that are applied to the firearm. Techniques relating to producing accurate ammunition are covered in internal and external ballistics, and handloading, and just like accurizing a firearm, the goal is to produce the most consistent possible results. The shooter must also be consistent, and this means that the fundamentals of marksmanship have to be followed rigorously; any failure