As I was reading below in Outdoor Life, the . 270 WSM (Winchester Short Magnum) favors lighter weight and stable bullets in the 130 to 150 grain class with a 1:10 twist rate. But what about a 165 or 175 grain bullet? Not so much as a longer bullet, for the same twist rate. It becomes less stable. Seems that Winchester engineers and hunters looking for a .270 with more moxie than the WSM for Big Game had to design the cartridge to fit a longer heavier bullet and came up with a new cartridge last year, the 6.8 Western and then design the twist rate faster 1:7.5 inches. If you like the .270 WSM then you also might like the new 6.8 Western in a Winchester Rifle if you shoot big game at long range, like on a western hunt. To reach further, the 6.8 Western is topped with a Nosler .277 165g ABLR with a G1 Ballistic Coefficient and Sectional Density that is tops in its class for retained energy. As well a Sierra bullet in the 175g class is available as well. The cartridge fills a hole for long range western hunting for those who choose that long range hunt capability.
The cartridge is made by both Browning and Winchester.
Great Winter Reading! But wait! I did a ballistic chart on the 165g Nosler AB. Lets look! The MPBR for this round is 333 yards with a 4 inch radius for elk/moose and still packs over a ton of energy at that range. Wow! And with a sectional density of .307 penetration is unbelievable with the AccuBond LR.
| Trajectory | |||
| Input Data | |||
| Ballistic Coefficient: | 0.600 G1 | Caliber: | 0.277 in |
| Bullet Weight: | 165.0 gr | ||
| Muzzle Velocity: | 2950.0 ft/s | Distance to Chronograph: | 0.0 ft |
| Sight Height: | 1.50 in | Sight Offset: | 0.00 in |
| Zero Height: | 0.00 in | Zero Offset: | 0.00 in |
| Windage: | 0.000 MOA | Elevation: | 0.000 MOA |
| Line Of Sight Angle: | 0.0 deg | Cant Angle: | 0.0 deg |
| Wind Speed: | 10.0 mph | Wind Angle: | 90.0 deg |
| Target Speed: | 10.0 mph | Target Angle: | 90.0 deg |
| Target Height: | 12.0 in | ||
| Temperature: | 59.0 °F | Pressure: | 29.92 in Hg |
| Humidity: | 0 % | Altitude: | 0.0 ft |
| Vital Zone Radius: | 4.0 in | ||
| Std. Atmosphere at Altitude: | No | Pressure is Corrected: | Yes |
| Zero at Max. Point Blank Range: | Yes | Target Relative Drops: | Yes |
| Mark Sound Barrier Crossing: | No | Include Extra Rows: | No |
| Column 1 Units: | 1.00 in | Column 2 Units: | 1.00 MOA |
| Round Output to Whole Numbers: | No | ||
| Output Data | |||
| Elevation: | 6.520 MOA | Windage: | 0.000 MOA |
| Atmospheric Density: | 0.07647 lb/ft³ | Speed of Sound: | 1116.4 ft/s |
| Maximum PBR: | 333 yd | Maximum PBR Zero: | 283 yd |
| Range of Maximum Height: | 157 yd | Energy at Maximum PBR: | 2178.2 ft•lbs |
| Sectional Density: | 0.307 lb/in² | ||
| Calculated Table | ||||||||||
| Range | Drop | Drop | Windage | Windage | Velocity | Mach | Energy | Time | Lead | Lead |
|---|---|---|---|---|---|---|---|---|---|---|
| (yd) | (in) | (MOA) | (in) | (MOA) | (ft/s) | (none) | (ft•lbs) | (s) | (in) | (MOA) |
| 0 | -1.5 | *** | 0.0 | *** | 2950.0 | 2.642 | 3187.8 | 0.000 | 0.0 | *** |
| 100 | 3.3 | 3.1 | 0.5 | 0.5 | 2790.0 | 2.499 | 2851.4 | 0.105 | 18.4 | 17.6 |
| 200 | 3.5 | 1.7 | 2.1 | 1.0 | 2635.7 | 2.361 | 2544.8 | 0.215 | 37.9 | 18.1 |
| 300 | -1.2 | -0.4 | 4.8 | 1.5 | 2486.6 | 2.227 | 2265.0 | 0.332 | 58.5 | 18.6 |
| 400 | -11.5 | -2.8 | 8.8 | 2.1 | 2342.4 | 2.098 | 2009.9 | 0.457 | 80.4 | 19.2 |
| 500 | -28.2 | -5.4 | 14.1 | 2.7 | 2203.0 | 1.973 | 1777.7 | 0.589 | 103.6 | 19.8 |
| 600 | -52.1 | -8.3 | 21.0 | 3.3 | 2068.2 | 1.852 | 1566.9 | 0.729 | 128.4 | 20.4 |
| 700 | -84.1 | -11.5 | 29.4 | 4.0 | 1938.4 | 1.736 | 1376.4 | 0.879 | 154.7 | 21.1 |
| 800 | -125.4 | -15.0 | 39.7 | 4.7 | 1813.8 | 1.625 | 1205.2 | 1.039 | 182.9 | 21.8 |
| 900 | -177.2 | -18.8 | 51.9 | 5.5 | 1695.0 | 1.518 | 1052.4 | 1.210 | 213.0 | 22.6 |
| 1000 | -241.2 | -23.0 | 66.3 | 6.3 | 1582.4 | 1.417 | 917.3 | 1.394 | 245.3 | 23.4 |
| 21-Jan-21 13:36, JBM/jbmtraj-5.1.cgi |
Good Hunting!