Load Specifications
Load data in caliber 6.5-300 Weatherby Mag. with .264 | 140gr | Sierra GameKing bullet and 49 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ADI AR 2218, Vihtavuori N570 and Alliant Reloder-33.
Important Notice: DO NOT go below Minimum Charge or above Maximum Charge. Since we have no control over the equipment and components used, any responsibility and liability for the results achieved is rejected.
Only powders/loads that match the current filter criteria are displayed: max pressure of a load ≤ 90% of max. standardized pressure, fill rate ≥ 80% and propellant combustion ≥ 95%. Use the sliders above the tables to adjust these thresholds.
Charge: Powder weight in grains. Start with the minimum load and work up carefully.
FR (Fill Rate): Case fill as a percentage. Values above 100% mean compressed loads.
MaxP / %: Maximum chamber pressure in bar and as a percentage of the standardized maximum for this caliber.
V(0): Muzzle velocity in feet per second (fps) at the standardized barrel length.
z (Powder Burn): Estimated propellant combustion percentage at bullet exit.
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Max Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 84% | 57,928 psi | 89% | 2940 fps | 100% |
| Accurate 8700ᴾ | <<locked>> | 100% | 54,056 psi | 83% | 2982 fps | 97.8% |
| Accurate MAGPRO | <<locked>> | 82% | 57,203 psi | 88% | 3048 fps | 99.7% |
| ADI AR 2209 | <<locked>> | 82% | 58,581 psi | 90% | 3022 fps | 100% |
| ADI AR 2213 | <<locked>> | 84% | 57,725 psi | 89% | 3045 fps | 100% |
| ADI AR 2217 | <<locked>> | 92% | 57,551 psi | 89% | 3035 fps | 100% |
| ADI AR 2218 | <<locked>> | 96% | 58,363 psi | 90% | 3169 fps | 99.3% |
| ADI AR 2225 | <<locked>> | 94% | 57,464 psi | 88% | 3058 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 82% | 58,218 psi | 90% | 3012 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 84% | 58,305 psi | 90% | 3038 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 84% | 56,521 psi | 87% | 2936 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 88% | 57,595 psi | 89% | 3022 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 92% | 56,304 psi | 87% | 3071 fps | 98.6% |
| Alliant Reloder-50 | <<locked>> | 96% | 56,579 psi | 87% | 3064 fps | 98.2% |
| Baschieri & Pellagri 109 | <<locked>> | 86% | 57,580 psi | 89% | 3005 fps | 99% |
| Bofors RP15 | <<locked>> | 86% | 57,740 psi | 89% | 3031 fps | 100% |
| Bofors RP30 | <<locked>> | 90% | 57,464 psi | 88% | 3045 fps | 100% |
| Bofors RP5 | <<locked>> | 84% | 58,305 psi | 90% | 3038 fps | 100% |
| Hodgdon H1000 | <<locked>> | 88% | 54,723 psi | 84% | 2989 fps | 100% |
| Hodgdon H4831 | <<locked>> | 82% | 56,086 psi | 86% | 2972 fps | 99.8% |
| Hodgdon H4831 SC | <<locked>> | 82% | 54,998 psi | 85% | 2953 fps | 99.7% |
| Hodgdon Retumbo | <<locked>> | 88% | 57,551 psi | 89% | 3117 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 38,087 psi | 59% | 1939 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 82% | 56,057 psi | 86% | 2946 fps | 99.8% |
| IMR 7828 SSC | <<locked>> | 84% | 56,376 psi | 87% | 3028 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 90% | 58,508 psi | 90% | 2963 fps | 96.4% |
| IMR 8133 Enduron | <<locked>> | 96% | 56,173 psi | 86% | 3038 fps | 100% |
| Lovex S071 | <<locked>> | 88% | 56,376 psi | 87% | 2913 fps | 100% |
| Norma 217 | <<locked>> | 96% | 57,986 psi | 89% | 3064 fps | 100% |
| Norma MRP | <<locked>> | 82% | 58,465 psi | 90% | 3051 fps | 100% |
| Ramshot Grand | <<locked>> | 84% | 58,030 psi | 89% | 3058 fps | 100% |
| Ramshot Magnum | <<locked>> | 86% | 56,478 psi | 87% | 2979 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 39,247 psi | 60% | 1988 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 88% | 58,378 psi | 90% | 3100 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 90% | 57,348 psi | 88% | 3071 fps | 99.8% |
| Rottweil R 904 | <<locked>> | 82% | 58,668 psi | 90% | 2992 fps | 100% |
| Rottweil R 905 | <<locked>> | 82% | 58,262 psi | 90% | 3009 fps | 100% |
| SNPE Vectan SP 13ᴾ | <<locked>> | 100% | 55,840 psi | 86% | 2992 fps | 97.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 82% | 57,899 psi | 89% | 3002 fps | 100% |
| Somchem S385 | <<locked>> | 82% | 58,218 psi | 90% | 2969 fps | 100% |
| Vihtavuori N165 | <<locked>> | 86% | 58,552 psi | 90% | 2963 fps | 100% |
| Vihtavuori N170 | <<locked>> | 90% | 57,986 psi | 89% | 2999 fps | 97.7% |
| Vihtavuori N555 | <<locked>> | 82% | 58,204 psi | 90% | 2969 fps | 100% |
| Vihtavuori N560 | <<locked>> | 82% | 57,667 psi | 89% | 3058 fps | 99.9% |
| Vihtavuori N565 | <<locked>> | 86% | 55,521 psi | 85% | 2995 fps | 99.8% |
| Vihtavuori N568 | <<locked>> | 90% | 57,725 psi | 89% | 3077 fps | 99.6% |
| Vihtavuori N570 | <<locked>> | 90% | 55,201 psi | 85% | 3074 fps | 98.1% |
| Winchester StaBALL HD | <<locked>> | 84% | 58,131 psi | 89% | 3031 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 84% | 58,117 psi | 89% | 2972 fps | 100% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 80% | 50,763 psi | 78% | 2828 fps | 100% |
| Accurate 8700 | <<locked>> | 96% | 46,746 psi | 72% | 2848 fps | 96% |
| Accurate MAGPRO | <<locked>> | 80% | 53,330 psi | 82% | 2982 fps | 99.3% |
| ADI AR 2209 | <<locked>> | 80% | 54,810 psi | 84% | 2963 fps | 100% |
| ADI AR 2213 | <<locked>> | 80% | 50,169 psi | 77% | 2917 fps | 99.5% |
| ADI AR 2217 | <<locked>> | 80% | 37,637 psi | 58% | 2654 fps | 97.3% |
| ADI AR 2218 | 79.9 gr | 88% | 43,250 psi | 67% | 2861 fps | 95.4% |
| ADI AR 2225 | <<locked>> | 80% | 35,128 psi | 54% | 2628 fps | 99% |
| Alliant Reloder-19 | <<locked>> | 80% | 54,563 psi | 84% | 2953 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 80% | 50,908 psi | 78% | 2917 fps | 99.9% |
| Alliant Reloder-23 | <<locked>> | 80% | 49,676 psi | 76% | 2831 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 43,830 psi | 67% | 2789 fps | 100% |
| Alliant Reloder-33 | 79.5 gr | 86% | 44,962 psi | 69% | 2854 fps | 95.9% |
| Alliant Reloder-50 | <<locked>> | 90% | 45,411 psi | 70% | 2851 fps | 95.4% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 47,369 psi | 73% | 2822 fps | 97.1% |
| Bofors RP15 | <<locked>> | 80% | 47,369 psi | 73% | 2848 fps | 99.7% |
| Bofors RP30 | <<locked>> | 80% | 41,002 psi | 63% | 2733 fps | 98.2% |
| Bofors RP5 | <<locked>> | 80% | 50,908 psi | 78% | 2917 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 80% | 41,191 psi | 63% | 2736 fps | 98.8% |
| Hodgdon H4831 | <<locked>> | 80% | 52,475 psi | 81% | 2910 fps | 99.5% |
| Hodgdon H4831 SC | <<locked>> | 80% | 51,459 psi | 79% | 2894 fps | 99.3% |
| Hodgdon Retumbo | <<locked>> | 80% | 43,207 psi | 66% | 2858 fps | 99.8% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,718 psi | 44% | 1736 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 52,605 psi | 81% | 2890 fps | 99.6% |
| IMR 7828 SSC | <<locked>> | 80% | 49,110 psi | 76% | 2904 fps | 99.4% |
| IMR 7977 Enduron | <<locked>> | 88% | 54,839 psi | 84% | 2904 fps | 95.7% |
| IMR 8133 Enduron | <<locked>> | 82% | 35,041 psi | 54% | 2605 fps | 96% |
| Lovex S071 | <<locked>> | 80% | 43,845 psi | 67% | 2703 fps | 100% |
| Norma 217 | <<locked>> | 80% | 33,156 psi | 51% | 2566 fps | 97.4% |
| Norma MRP | <<locked>> | 80% | 54,491 psi | 84% | 2986 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 50,154 psi | 77% | 2923 fps | 99.7% |
| Ramshot Magnum | <<locked>> | 80% | 45,237 psi | 70% | 2789 fps | 99.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,472 psi | 45% | 1778 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 42,931 psi | 66% | 2831 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 80% | 39,494 psi | 61% | 2720 fps | 96.2% |
| Rottweil R 904 | <<locked>> | 80% | 54,998 psi | 85% | 2933 fps | 99.9% |
| Rottweil R 905 | <<locked>> | 80% | 54,520 psi | 84% | 2949 fps | 100% |
| SNPE Vectan SP 13 | <<locked>> | 94% | 45,513 psi | 70% | 2799 fps | 95.2% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 54,172 psi | 83% | 2943 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 54,621 psi | 84% | 2917 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 48,138 psi | 74% | 2795 fps | 99.9% |
| Vihtavuori N170 | <<locked>> | 84% | 47,471 psi | 73% | 2808 fps | 95.2% |
| Vihtavuori N555 | <<locked>> | 80% | 54,723 psi | 84% | 2913 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 53,780 psi | 83% | 2989 fps | 99.6% |
| Vihtavuori N565 | <<locked>> | 80% | 45,266 psi | 70% | 2805 fps | 98.6% |
| Vihtavuori N568 | <<locked>> | 80% | 40,350 psi | 62% | 2736 fps | 96% |
| Vihtavuori N570 | 74.7 gr | 84% | 44,585 psi | 69% | 2861 fps | 95.3% |
| Winchester StaBALL HD | <<locked>> | 80% | 50,212 psi | 77% | 2913 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 50,676 psi | 78% | 2851 fps | 99.9% |
Recommended = one of the top powders for this cartridge and bullet combination.
ᴾ possible press load - work up slowly to this load while watching for signs of excessive pressure.
This overview compares 49 powders for 6.5-300 Weatherby Mag. loaded with the .264 | 140gr | Sierra GameKing. ADI AR 2218 delivers the highest muzzle velocity at 3,169 fps; across all powders the maximum-charge window runs from 1,939 fps to 3,169 fps. Accurate 8700 gives the best case fill at 100 %, and 49 of the 49 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (448 MPa), the top charges use 59–90 %, leaving at least 10 % headroom. The 140.0 gr projectile in 0.264" calls for a 1:10.0 twist; slower twists will usually not stabilise this weight. Accurate 8700, Hodgdon TrailBoss, ReloadSwiss RS 14 reach 100 % fill or more at maximum charge, so these are compressed loads: they need a long drop tube to seat cleanly and react sensitively to the case capacity of your own brass lot. ADI AR 2218, Vihtavuori N570, Alliant Reloder-33 rank at the top here: for 6.5-300 Weatherby Mag. with the .264 | 140gr | Sierra GameKing they combine a high case fill with complete burn and sit in the upper velocity band. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.