The case’s length-to-diameter ratio is said to provide better ignition and a more efficient powder burn, and the sharp shoulder makes the powder burn in the case rather than blowtorching down the bore. 270 Winchester Short Magnum (WSM) case shortened by 0.08 inch, with the same 35-degree shoulder. The 6.8 Western was introduced by Winchester in 2021 and seemed to be a hit right out of the box, as it has been used on all sorts of game in all sorts of places, both here and overseas. The round could be chambered in rifles that are not too heavy to tote over hill and dale after mountain species, without the recoil of the very popular. The idea was to produce a cartridge with a bit more reach than the 6.5mms that would be suitable for game as large as elk but not overpowered for deer, sheep, and similarly sized critters. As its name suggests, the cartridge is geared for wide-open spaces where game may be shot at extended ranges. Enter the 6.8 WesternĪll these precise design features apply directly to the 6.8 Western cartridge. 270-caliber bullets suitable for long-range target shooting or hunting big game include: (from left) the Barnes 130-grain TTSX, Berger 150-grain VLD, Berger 170-grain EOL Elite Hunter, Federal 136-grain Edge TLR, Federal 140-grain TBT, Hornady 145-grain ELD-X, Hornady 150-grain SST, Nosler 150-grain Partition, Nosler 150-grain ABLR, Nosler 165-grain ABLR, Sierra 140-grain HPBT, Sierra 140-grain Tipped GameKing, and Swift 130-grain Scirocco II. Several newer powders have “de-coppering” agents in them that really reduce bullet-jacket fouling and make bore cleaning easier and quicker. These long bullets require faster twist rates, such as 1:8, 1:7, and even 1:6.5.Īdditionally, the powders used in these new, short and fat cases are carefully selected to optimize the cartridge’s performance. Modern bullets for such cartridges are heavier than previous bullets of the caliber, and long for their caliber, with high ballistic coefficients (BC) for flat trajectories and high sectional densities for deep penetration at long ranges. It is rather long so that the bullets can be seated out and not protrude into the case and take up volume better used for propellant. The leade ahead of the chamber is likewise precisely designed to aid accuracy. 270-caliber bullets makes reloading the 6.8 Western a challenging but fun exercise. Accurate bullets designed for such chambers-i.e., long, sleek bullets with skinny points and uniform jackets-are available. If the bullet starts out lined up with the throat, then a big chunk of the accuracy equation is solved. If the bullet tips on its way to the rifling, its center of gravity shifts, and accuracy is seriously degraded. This “tipping” is called in-bore yaw or principal axis tilt. This prevents the bullet from tipping as it leaves the case and heads toward the rifling. The diameter of the chamber throat is very tight, just 0.001 to 0.002 inch over the bullet diameter.
HODGEN LOCAD DATA FULL
The neck is at least one caliber long so that the bullet can be seated with full contact, with nothing except the boattail (if present) protruding into the case proper. The case of the modern-day accuracy cartridge has to fit into a short action and have a sharp shoulder, usually around 30 degrees. To this list we must add the recent and highly efficient 6.8 Western. This triumvirate of features has produced such outstanding cartridges as the 224 Valkyrie, 6mm ARC, 6.5 Creedmoor, 6mm Creedmoor, 6.5 PRC, and numerous wildcats. Bob Dylan was right: “… the times they are a-changin’.” Major advances in cartridge, case, and bullet designs have dramatically altered the shooting landscape, and for the better.
0 kommentar(er)
