Search results
Results from the WOW.Com Content Network
The standard bullet diameter for 6 mm caliber cartridges is .243 inches (6.2 mm), the same diameter used in the .243 Winchester and 6mm Remington cartridges. 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 ...
The .243 produces a velocity of 3,200 feet (980 m) per second from factory-loaded expanding monolithic copper projectiles weighing 85 grains (5.5 g) fired from a 24-inch (610 mm) barrel. [28] Other variations of commercially loaded .243 ammunition are available with bullet weights ranging from 55 grains (3.6 g) up to 115 grains (6.8 g).
Newton recommended loading 100 grain (6.5 g) bullets at 2,800 ft/s (850 m/s); but Savage Arms reduced bullet weight to obtain a velocity of 3,000 ft/s (910 m/s), making it the first American cartridge capable of that velocity. Achieving that velocity may have been the reason for the choice of the light-for-caliber 87-grain (5.6 g) bullet. [3]
Remington determined that a 90 grain soft point .244 hunting bullet was well suited for medium-sized big game hunting purposes. For the length and weight of its 90 grain soft point hunting bullet, Remington selected a 1 in 12-inch twist. By selecting the slowest twist possible, Remington was seeking to avoid excessive spin.
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.
The .243 Winchester Super Short Magnum or .243 WSSM is a rifle cartridge introduced in 2003. It uses a .300 WSM (Winchester Short Magnum) case shortened and necked down to accept a .243in/6mm diameter bullet, and is a high velocity round based on ballistics design philosophies that are intended to produce a high level of efficiency. [2]
The .308 Winchester has slightly more drop at long range than the .30-06 Springfield, owing to its slightly lower (around 30 metres per second (100 ft/s)) muzzle velocity with most bullet weights. Cartridges with significantly higher muzzle velocities, such as the .300 Winchester Magnum can have significantly less drop at long range, but much ...
WSM and WSSM family of cartridges. From left to right: .223 WSSM, .243 WSSM, .25 WSSM, .270 WSM, 7 mm WSM, .300 WSM, .325 WSM. Winchester Super Short Magnum, or WSSM is a line of rebated bottlenecked centerfire short magnum cartridges introduced by the U.S. Repeating Arms Company (Winchester Inc). [1]