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The .308 Winchester has a 3.64 mL (56 gr H 2 O) cartridge case capacity. [9] The exterior shape of the case was designed to promote reliable case feeding and extraction in bolt-action rifles and machine guns alike, under extreme conditions. .308 Winchester maximum C.I.P. cartridge dimensions. All dimensions in millimeters (mm) and inches.
Once all the cartridges had been tested at 18" and the barrels were cut and ready, each brand was tested again at 17" and so on, right down to a 2" barrel. Three rounds of each brand of ammunition were fired at each barrel length and the velocity of the bullet was recorded as it passed over two commercial chronographs 15 feet away.
The final result is a barrel that is mirror-smooth, and with a consistent or slightly tapering bore. The hand-lapping technique uses a wooden or soft metal rod to pull or push the slug through the bore, while the newer fire-lapping technique uses specially loaded, low-power cartridges to push abrasive-covered soft-lead bullets down the barrel.
For projectiles in unpowered flight, its velocity is highest at leaving the muzzle and drops off steadily because of air resistance.Projectiles traveling less than the speed of sound (about 340 m/s (1,100 ft/s) in dry air at sea level) are subsonic, while those traveling faster are supersonic and thus can travel a substantial distance and even hit a target before a nearby observer hears the ...
The .308 Marlin Express is a cartridge developed in 2007 by Marlin Firearms and Hornady. It is based on the .307 Winchester with a goal to duplicate .308 Winchester performance. The cartridge uses a slightly shorter, semi-rimmed case similar to that of the .220 Swift to function in lever-action rifles.
Muzzle energy is dependent upon the factors previously listed, and velocity is highly variable depending upon the length of the barrel a projectile is fired from. [2] Also the muzzle energy is only an upper limit for how much energy is transmitted to the target, and the effects of a ballistic trauma depend on several other factors as well.
Miller twist rule is a mathematical formula derived by American physical chemist and historian of science Donald G. Miller (1927-2012) to determine the rate of twist to apply to a given bullet to provide optimum stability using a rifled barrel. [1]
In order to make accurate predictions on gyroscopic drift several details about both the external and internal ballistics must be considered. Factors such as the twist rate of the barrel, the velocity of the projectile as it exits the muzzle, barrel harmonics, and atmospheric conditions, all contribute to the path of a projectile.