Search results
Results From The WOW.Com Content Network
Thus the optimum rate of twist for this bullet should be approximately 12 inches per turn. The typical twist of .30-06 caliber rifle barrels is 10 inches per turn, accommodating heavier bullets than in this example. A different twist rate often helps explain why some bullets work better in certain rifles when fired under similar conditions.
To obtain maximum accuracy, bullet weight and form are matched to the rifling twist rate of the barrel. Typically, 68 gr (4.41 g) bullets are used in barrels with twist rates of 1 in 13 inch (1 in 330 mm), while 1 in 15 inch (1 in 380 mm) barrel twists can accommodate lighter 58 or 60 gr (3.76 or 3.89 g) accurately.
Values courtesy of the Hornady Ballistic Calculator [14] For the purposes of this comparison barrel a barrel length of 24 in (610 mm) is used. The .458 Lott is able to attain over 2,300-foot-per-second (700 m/s) with a 500-grain (32 g) jacketed bullet at safe pressure levels from a 23–24-inch (580–610 mm) barrel.
The 6.5mm Creedmoor designated as 6.5 Creedmoor by SAAMI, and as 6,5 Creedmoor by the C.I.P. [4] is a centerfire rifle cartridge introduced by Hornady in 2007. [6]It was developed by Hornady senior ballistics scientist Dave Emary in partnership with Dennis DeMille, the vice-president of product development at Creedmoor Sports, hence the name.
A 254 mm (1 in 10 in) twist rate is also commonly applied. [ 11 ] According to the official C.I.P. ( Commission internationale permanente pour l'épreuve des armes à feu portatives ) rulings, the .308 Winchester can handle up to 415.00 MPa (60,191 psi) P max piezo pressure.
The cartridge was a co-development between Ruger and Hornady where Ruger developed the rifles and Hornady the ammunition. Compared to the .416 Ruger, the Remington cartridge has a greater case capacity and a higher S.A.A.M.I. recommended pressure level. This means that the Remington cartridge should perform better than the Ruger cartridge.
These bullets include most Barnes' bullets over 110 gr (7.1 g) and any conventional spitzer bullet of over 115 gr (7.5 g). Hornady's 117 gr (7.6 g) round nose bullet is made for such firearms which have the slower spin rate. Norma loads this bullet in the Weatherby's H257117RN ammunition for owner of such rifles who require a heavier bullet.
Source(s): Barnes, Federal, Hornady factory specifications, AccurateShooter.com [1] The .243 Winchester ( 6×52mm ) is a popular sporting rifle cartridge. Developed as a versatile short action cartridge to hunt both medium game and small game alike, it "took whitetail hunting by storm" [ 2 ] when introduced in 1955, and remains one of the most ...