Load Specifications
Load data in caliber 6.5-300 Weatherby Mag. with .263 | 123gr | Prvi Partizan SP bullet and 50 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Hodgdon Retumbo, ADI AR 2218 and Vihtavuori N570.
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>> | 86% | 57,450 psi | 88% | 3097 fps | 100% |
| Accurate High Country | <<locked>> | 82% | 55,535 psi | 85% | 3192 fps | 99.5% |
| Accurate MAGPRO | <<locked>> | 84% | 56,681 psi | 87% | 3202 fps | 99% |
| ADI AR 2209 | <<locked>> | 84% | 58,421 psi | 90% | 3186 fps | 100% |
| ADI AR 2213 | <<locked>> | 86% | 57,145 psi | 88% | 3199 fps | 99.6% |
| ADI AR 2217 | <<locked>> | 94% | 56,536 psi | 87% | 3179 fps | 99.8% |
| ADI AR 2218 | <<locked>> | 98% | 57,334 psi | 88% | 3301 fps | 98.1% |
| ADI AR 2225 | <<locked>> | 96% | 55,883 psi | 86% | 3202 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 84% | 57,957 psi | 89% | 3173 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 86% | 57,638 psi | 89% | 3196 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 86% | 55,927 psi | 86% | 3100 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 90% | 56,710 psi | 87% | 3176 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 82% | 56,739 psi | 87% | 3182 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 94% | 55,187 psi | 85% | 3205 fps | 97.3% |
| Alliant Reloder-50 | <<locked>> | 98% | 55,100 psi | 85% | 3186 fps | 96.7% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 57,435 psi | 88% | 3153 fps | 98% |
| Bofors RP15 | <<locked>> | 88% | 57,058 psi | 88% | 3182 fps | 99.9% |
| Bofors RP30 | <<locked>> | 92% | 56,434 psi | 87% | 3189 fps | 99.8% |
| Bofors RP5 | <<locked>> | 86% | 57,638 psi | 89% | 3196 fps | 100% |
| Hodgdon H1000 | <<locked>> | 92% | 57,972 psi | 89% | 3202 fps | 100% |
| Hodgdon H4831 | <<locked>> | 84% | 55,999 psi | 86% | 3130 fps | 99.2% |
| Hodgdon H4831 SC | <<locked>> | 86% | 58,653 psi | 90% | 3176 fps | 99.5% |
| Hodgdon Hybrid 100V | <<locked>> | 82% | 58,479 psi | 90% | 3087 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 90% | 56,057 psi | 86% | 3264 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,884 psi | 58% | 2060 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 84% | 56,101 psi | 86% | 3107 fps | 99.3% |
| IMR 7828 SSC | <<locked>> | 86% | 55,854 psi | 86% | 3186 fps | 99.5% |
| IMR 8133 Enduron | <<locked>> | 98% | 54,998 psi | 85% | 3176 fps | 99.6% |
| Lovex S071 | <<locked>> | 90% | 55,912 psi | 86% | 3071 fps | 100% |
| Norma 217 | <<locked>> | 98% | 56,289 psi | 87% | 3205 fps | 100% |
| Norma MRP | <<locked>> | 84% | 58,059 psi | 89% | 3212 fps | 100% |
| Ramshot Grand | <<locked>> | 86% | 57,145 psi | 88% | 3209 fps | 99.8% |
| Ramshot Magnum | <<locked>> | 88% | 55,753 psi | 86% | 3133 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,957 psi | 60% | 2110 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 90% | 57,014 psi | 88% | 3251 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 92% | 56,362 psi | 87% | 3212 fps | 99.1% |
| Rottweil R 904 | <<locked>> | 84% | 58,711 psi | 90% | 3156 fps | 99.7% |
| Rottweil R 905 | <<locked>> | 84% | 57,754 psi | 89% | 3166 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 84% | 57,377 psi | 88% | 3163 fps | 100% |
| Somchem S361 | <<locked>> | 82% | 56,362 psi | 87% | 3081 fps | 99.3% |
| Somchem S385 | <<locked>> | 84% | 58,160 psi | 90% | 3133 fps | 100% |
| Vihtavuori N165 | <<locked>> | 88% | 58,349 psi | 90% | 3123 fps | 100% |
| Vihtavuori N170 | <<locked>> | 92% | 57,711 psi | 89% | 3143 fps | 96.4% |
| Vihtavuori N555 | <<locked>> | 84% | 57,725 psi | 89% | 3133 fps | 100% |
| Vihtavuori N560 | <<locked>> | 84% | 57,348 psi | 88% | 3215 fps | 99.4% |
| Vihtavuori N565 | <<locked>> | 90% | 58,581 psi | 90% | 3209 fps | 99.6% |
| Vihtavuori N568 | <<locked>> | 92% | 56,579 psi | 87% | 3215 fps | 98.8% |
| Vihtavuori N570 | <<locked>> | 94% | 58,160 psi | 90% | 3281 fps | 97.5% |
| Winchester StaBALL HD | <<locked>> | 86% | 56,942 psi | 88% | 3196 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 86% | 57,986 psi | 89% | 3130 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% | 46,934 psi | 72% | 2917 fps | 100% |
| Accurate High Country | <<locked>> | 80% | 51,779 psi | 80% | 3120 fps | 99% |
| Accurate MAGPRO | <<locked>> | 80% | 49,168 psi | 76% | 3058 fps | 97.6% |
| ADI AR 2209 | <<locked>> | 80% | 50,952 psi | 78% | 3058 fps | 99.5% |
| ADI AR 2213 | <<locked>> | 80% | 46,369 psi | 71% | 2995 fps | 98% |
| ADI AR 2217 | <<locked>> | 82% | 37,086 psi | 57% | 2776 fps | 95.5% |
| ADI AR 2218 | 86.8 gr | 94% | 49,313 psi | 76% | 3136 fps | 95.9% |
| ADI AR 2225 | <<locked>> | 80% | 31,908 psi | 49% | 2671 fps | 96.3% |
| Alliant Reloder-19 | <<locked>> | 80% | 50,821 psi | 78% | 3048 fps | 99.5% |
| Alliant Reloder-22 | <<locked>> | 80% | 47,137 psi | 73% | 2999 fps | 99% |
| Alliant Reloder-23 | <<locked>> | 80% | 45,818 psi | 71% | 2930 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 39,972 psi | 62% | 2861 fps | 99.8% |
| Alliant Reloder-26 | <<locked>> | 80% | 52,605 psi | 81% | 3117 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 90% | 47,355 psi | 73% | 3048 fps | 95.1% |
| Alliant Reloder-50 | <<locked>> | 96% | 51,227 psi | 79% | 3114 fps | 95.7% |
| Baschieri & Pellagri 109 | <<locked>> | 82% | 47,166 psi | 73% | 2959 fps | 95.7% |
| Bofors RP15 | <<locked>> | 80% | 43,903 psi | 68% | 2930 fps | 98.3% |
| Bofors RP30 | <<locked>> | 80% | 37,362 psi | 57% | 2789 fps | 95.6% |
| Bofors RP5 | <<locked>> | 80% | 47,137 psi | 73% | 2999 fps | 99% |
| Hodgdon H1000 | <<locked>> | 80% | 37,637 psi | 58% | 2792 fps | 96.4% |
| Hodgdon H4831 | <<locked>> | 80% | 48,704 psi | 75% | 2995 fps | 98% |
| Hodgdon H4831 SC | <<locked>> | 80% | 47,950 psi | 74% | 2979 fps | 97.8% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 54,984 psi | 85% | 3035 fps | 100% |
| Hodgdon Retumbo | 69.7 gr | 80% | 39,102 psi | 60% | 2910 fps | 98% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,514 psi | 44% | 1847 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 49,269 psi | 76% | 2979 fps | 98.3% |
| IMR 7828 SSC | <<locked>> | 80% | 45,078 psi | 69% | 2976 fps | 97.7% |
| IMR 8133 Enduron | <<locked>> | 88% | 39,015 psi | 60% | 2844 fps | 96% |
| Lovex S071 | <<locked>> | 80% | 40,596 psi | 62% | 2785 fps | 99.4% |
| Norma 217 | <<locked>> | 82% | 32,039 psi | 49% | 2671 fps | 95.3% |
| Norma MRP | <<locked>> | 80% | 50,256 psi | 77% | 3074 fps | 99.9% |
| Ramshot Grand | <<locked>> | 80% | 45,629 psi | 70% | 2992 fps | 98.2% |
| Ramshot Magnum | <<locked>> | 80% | 41,263 psi | 64% | 2858 fps | 98.6% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,225 psi | 45% | 1886 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 38,667 psi | 60% | 2884 fps | 98.8% |
| ReloadSwiss RS 80 | <<locked>> | 84% | 41,597 psi | 64% | 2910 fps | 95.4% |
| Rottweil R 904 | <<locked>> | 80% | 51,430 psi | 79% | 3028 fps | 99% |
| Rottweil R 905 | <<locked>> | 80% | 50,618 psi | 78% | 3038 fps | 99.5% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 50,270 psi | 77% | 3035 fps | 99.5% |
| Somchem S361 | <<locked>> | 80% | 52,620 psi | 81% | 3015 fps | 98.7% |
| Somchem S385 | <<locked>> | 80% | 50,995 psi | 78% | 3012 fps | 99.9% |
| Vihtavuori N165 | <<locked>> | 80% | 44,628 psi | 69% | 2877 fps | 99% |
| Vihtavuori N170 | <<locked>> | 90% | 53,940 psi | 83% | 3074 fps | 95.5% |
| Vihtavuori N555 | <<locked>> | 80% | 50,691 psi | 78% | 3018 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 49,719 psi | 77% | 3074 fps | 98.3% |
| Vihtavuori N565 | <<locked>> | 80% | 41,626 psi | 64% | 2871 fps | 96.4% |
| Vihtavuori N568 | <<locked>> | 84% | 42,569 psi | 66% | 2930 fps | 95.2% |
| Vihtavuori N570 | 81.4 gr | 90% | 50,357 psi | 78% | 3130 fps | 95.6% |
| Winchester StaBALL HD | <<locked>> | 80% | 45,281 psi | 70% | 2999 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 47,152 psi | 73% | 2936 fps | 99.1% |
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 50 powders for 6.5-300 Weatherby Mag. loaded with the .263 | 123gr | Prvi Partizan SP. ADI AR 2218 delivers the highest muzzle velocity at 3,301 fps; across all powders the maximum-charge window runs from 2,060 fps to 3,301 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 50 of the 50 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (448 MPa), the top charges use 58–90 %, leaving at least 10 % headroom. The 123.0 gr projectile in 0.263" calls for a 1:11.0 twist; slower twists will usually not stabilise this weight. 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. Hodgdon Retumbo, ADI AR 2218, Vihtavuori N570 rank at the top here: for 6.5-300 Weatherby Mag. with the .263 | 123gr | Prvi Partizan SP 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.