Load Specifications
Load data in caliber 6.5-300 Weatherby Mag. with .263 | 139gr | Prvi Partizan SP BT 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% | 57,841 psi | 89% | 2946 fps | 100% |
| Accurate 8700ᴾ | <<locked>> | 100% | 53,867 psi | 83% | 2986 fps | 97.7% |
| Accurate MAGPRO | <<locked>> | 82% | 57,101 psi | 88% | 3058 fps | 99.6% |
| ADI AR 2209 | <<locked>> | 82% | 58,552 psi | 90% | 3028 fps | 100% |
| ADI AR 2213 | <<locked>> | 84% | 57,435 psi | 88% | 3048 fps | 100% |
| ADI AR 2217 | <<locked>> | 92% | 57,188 psi | 88% | 3038 fps | 100% |
| ADI AR 2218 | <<locked>> | 96% | 58,175 psi | 90% | 3173 fps | 99.2% |
| ADI AR 2225 | <<locked>> | 94% | 57,087 psi | 88% | 3058 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 82% | 57,914 psi | 89% | 3015 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 84% | 58,015 psi | 89% | 3041 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 84% | 56,463 psi | 87% | 2946 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 88% | 57,508 psi | 89% | 3025 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 92% | 55,927 psi | 86% | 3071 fps | 98.5% |
| Alliant Reloder-50 | <<locked>> | 96% | 56,391 psi | 87% | 3071 fps | 98.2% |
| Baschieri & Pellagri 109 | <<locked>> | 86% | 57,508 psi | 89% | 3012 fps | 98.9% |
| Bofors RP15 | <<locked>> | 86% | 57,653 psi | 89% | 3035 fps | 100% |
| Bofors RP30 | <<locked>> | 90% | 57,363 psi | 88% | 3051 fps | 100% |
| Bofors RP5 | <<locked>> | 84% | 58,015 psi | 89% | 3041 fps | 100% |
| Hodgdon H1000 | <<locked>> | 90% | 58,581 psi | 90% | 3054 fps | 100% |
| Hodgdon H4831 | <<locked>> | 82% | 56,014 psi | 86% | 2979 fps | 99.7% |
| Hodgdon H4831 SC | <<locked>> | 84% | 58,668 psi | 90% | 3022 fps | 99.9% |
| Hodgdon Retumbo | <<locked>> | 88% | 57,406 psi | 88% | 3120 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 38,145 psi | 59% | 1949 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 82% | 55,999 psi | 86% | 2953 fps | 99.8% |
| IMR 7828 SSC | <<locked>> | 84% | 56,275 psi | 87% | 3038 fps | 99.9% |
| IMR 7977 Enduron | <<locked>> | 90% | 58,204 psi | 90% | 2966 fps | 96.3% |
| IMR 8133 Enduron | <<locked>> | 96% | 56,043 psi | 86% | 3045 fps | 100% |
| Lovex S071 | <<locked>> | 88% | 56,318 psi | 87% | 2920 fps | 100% |
| Norma 217 | <<locked>> | 96% | 57,827 psi | 89% | 3068 fps | 100% |
| Norma MRP | <<locked>> | 82% | 58,392 psi | 90% | 3054 fps | 100% |
| Ramshot Grand | <<locked>> | 84% | 57,696 psi | 89% | 3061 fps | 100% |
| Ramshot Magnum | <<locked>> | 86% | 56,130 psi | 86% | 2986 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 39,117 psi | 60% | 1991 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 88% | 58,233 psi | 90% | 3107 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 90% | 57,203 psi | 88% | 3074 fps | 99.7% |
| Rottweil R 904 | <<locked>> | 82% | 58,624 psi | 90% | 2999 fps | 100% |
| Rottweil R 905 | <<locked>> | 82% | 57,972 psi | 89% | 3009 fps | 100% |
| SNPE Vectan SP 13ᴾ | <<locked>> | 100% | 55,695 psi | 86% | 2995 fps | 97.7% |
| SNPE Vectan Tubal 8000 | <<locked>> | 82% | 57,609 psi | 89% | 3009 fps | 100% |
| Somchem S385 | <<locked>> | 82% | 58,189 psi | 90% | 2976 fps | 100% |
| Vihtavuori N165 | <<locked>> | 86% | 58,465 psi | 90% | 2969 fps | 100% |
| Vihtavuori N170 | <<locked>> | 90% | 57,841 psi | 89% | 3005 fps | 97.6% |
| Vihtavuori N555 | <<locked>> | 82% | 58,131 psi | 89% | 2976 fps | 100% |
| Vihtavuori N560 | <<locked>> | 82% | 57,580 psi | 89% | 3061 fps | 99.9% |
| Vihtavuori N565 | <<locked>> | 86% | 55,434 psi | 85% | 3005 fps | 99.8% |
| Vihtavuori N568 | <<locked>> | 90% | 57,363 psi | 88% | 3077 fps | 99.5% |
| Vihtavuori N570 | <<locked>> | 90% | 55,056 psi | 85% | 3077 fps | 98% |
| Winchester StaBALL HD | <<locked>> | 84% | 58,030 psi | 89% | 3041 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 84% | 58,044 psi | 89% | 2976 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% | 50,517 psi | 78% | 2831 fps | 100% |
| Accurate 8700 | <<locked>> | 96% | 46,586 psi | 72% | 2851 fps | 95.9% |
| Accurate MAGPRO | <<locked>> | 80% | 53,055 psi | 82% | 2986 fps | 99.2% |
| ADI AR 2209 | <<locked>> | 80% | 54,766 psi | 84% | 2969 fps | 100% |
| ADI AR 2213 | <<locked>> | 80% | 50,096 psi | 77% | 2923 fps | 99.5% |
| ADI AR 2217 | <<locked>> | 80% | 37,594 psi | 58% | 2657 fps | 97.2% |
| ADI AR 2218 | 80.1 gr | 88% | 43,163 psi | 66% | 2864 fps | 95.2% |
| ADI AR 2225 | <<locked>> | 80% | 34,925 psi | 54% | 2628 fps | 98.9% |
| Alliant Reloder-19 | <<locked>> | 80% | 54,317 psi | 84% | 2956 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 80% | 50,836 psi | 78% | 2923 fps | 99.9% |
| Alliant Reloder-23 | <<locked>> | 80% | 49,632 psi | 76% | 2841 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 43,772 psi | 67% | 2795 fps | 100% |
| Alliant Reloder-33 | 79.7 gr | 86% | 44,846 psi | 69% | 2858 fps | 95.8% |
| Alliant Reloder-50 | <<locked>> | 90% | 45,092 psi | 69% | 2851 fps | 95.2% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 47,166 psi | 73% | 2822 fps | 97% |
| Bofors RP15 | <<locked>> | 80% | 47,311 psi | 73% | 2854 fps | 99.6% |
| Bofors RP30 | <<locked>> | 80% | 40,785 psi | 63% | 2733 fps | 98.1% |
| Bofors RP5 | <<locked>> | 80% | 50,836 psi | 78% | 2923 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 80% | 40,959 psi | 63% | 2736 fps | 98.7% |
| Hodgdon H4831 | <<locked>> | 80% | 52,228 psi | 80% | 2913 fps | 99.4% |
| Hodgdon H4831 SC | <<locked>> | 80% | 51,401 psi | 79% | 2900 fps | 99.3% |
| Hodgdon Retumbo | <<locked>> | 80% | 42,931 psi | 66% | 2858 fps | 99.7% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,631 psi | 44% | 1742 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 52,562 psi | 81% | 2894 fps | 99.5% |
| IMR 7828 SSC | <<locked>> | 80% | 48,863 psi | 75% | 2904 fps | 99.3% |
| IMR 7977 Enduron | <<locked>> | 88% | 54,781 psi | 84% | 2910 fps | 95.5% |
| IMR 8133 Enduron | <<locked>> | 82% | 34,824 psi | 54% | 2602 fps | 95.7% |
| Lovex S071 | <<locked>> | 80% | 43,642 psi | 67% | 2707 fps | 100% |
| Norma 217 | <<locked>> | 80% | 33,083 psi | 51% | 2569 fps | 97.3% |
| Norma MRP | <<locked>> | 80% | 54,404 psi | 84% | 2992 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 49,879 psi | 77% | 2927 fps | 99.6% |
| Ramshot Magnum | <<locked>> | 80% | 44,976 psi | 69% | 2792 fps | 99.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,544 psi | 45% | 1785 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 42,685 psi | 66% | 2835 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 80% | 39,233 psi | 60% | 2720 fps | 96% |
| Rottweil R 904 | <<locked>> | 80% | 54,940 psi | 85% | 2940 fps | 99.9% |
| Rottweil R 905 | <<locked>> | 80% | 54,288 psi | 84% | 2953 fps | 100% |
| SNPE Vectan SP 13 | <<locked>> | 94% | 45,237 psi | 70% | 2799 fps | 95% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 53,940 psi | 83% | 2949 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 54,549 psi | 84% | 2923 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 47,921 psi | 74% | 2799 fps | 99.9% |
| Vihtavuori N170 | <<locked>> | 84% | 47,384 psi | 73% | 2815 fps | 95.1% |
| Vihtavuori N555 | <<locked>> | 80% | 54,476 psi | 84% | 2920 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 53,708 psi | 83% | 2999 fps | 99.6% |
| Vihtavuori N565 | <<locked>> | 80% | 45,194 psi | 70% | 2812 fps | 98.5% |
| Vihtavuori N568 | <<locked>> | 80% | 40,277 psi | 62% | 2740 fps | 95.8% |
| Vihtavuori N570 | 74.9 gr | 84% | 44,454 psi | 68% | 2864 fps | 95.1% |
| Winchester StaBALL HD | <<locked>> | 80% | 50,082 psi | 77% | 2920 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 50,647 psi | 78% | 2858 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 .263 | 139gr | Prvi Partizan SP BT. ADI AR 2218 delivers the highest muzzle velocity at 3,173 fps; across all powders the maximum-charge window runs from 1,949 fps to 3,173 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 139.0 gr projectile in 0.263" calls for a 1:10.5 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 .263 | 139gr | Prvi Partizan SP BT 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.