Load Specifications
Load data in caliber 6.5-300 Weatherby Mag. with .264 | 125gr | Hasler ARIETE bullet and 50 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Vihtavuori N570, Hodgdon Retumbo and ReloadSwiss RS 76.
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% | 55,811 psi | 86% | 3054 fps | 100% |
| Accurate MAGPRO | <<locked>> | 86% | 58,740 psi | 90% | 3219 fps | 99.2% |
| ADI AR 2209 | <<locked>> | 84% | 56,869 psi | 88% | 3140 fps | 99.9% |
| ADI AR 2213 | <<locked>> | 86% | 55,463 psi | 85% | 3153 fps | 99.5% |
| ADI AR 2217 | <<locked>> | 96% | 58,508 psi | 90% | 3196 fps | 99.9% |
| ADI AR 2218 | <<locked>> | 98% | 54,868 psi | 84% | 3238 fps | 97.5% |
| ADI AR 2225 | <<locked>> | 98% | 57,783 psi | 89% | 3219 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 84% | 56,318 psi | 87% | 3127 fps | 99.9% |
| Alliant Reloder-22 | <<locked>> | 86% | 55,985 psi | 86% | 3150 fps | 99.9% |
| Alliant Reloder-23 | <<locked>> | 88% | 57,928 psi | 89% | 3114 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 92% | 58,537 psi | 90% | 3192 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 82% | 54,737 psi | 84% | 3140 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 96% | 56,855 psi | 88% | 3222 fps | 97.7% |
| Alliant Reloder-50ᴾ | <<locked>> | 100% | 56,913 psi | 88% | 3212 fps | 97.2% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 55,956 psi | 86% | 3114 fps | 97.8% |
| Bofors RP15 | <<locked>> | 88% | 55,448 psi | 85% | 3136 fps | 99.9% |
| Bofors RP30 | <<locked>> | 94% | 58,392 psi | 90% | 3205 fps | 99.9% |
| Bofors RP5 | <<locked>> | 86% | 55,985 psi | 86% | 3150 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 92% | 56,014 psi | 86% | 3156 fps | 99.9% |
| Hodgdon H4831 | <<locked>> | 86% | 58,276 psi | 90% | 3146 fps | 99.4% |
| Hodgdon H4831 SC | <<locked>> | 86% | 57,130 psi | 88% | 3130 fps | 99.3% |
| Hodgdon Hybrid 100V | <<locked>> | 82% | 56,942 psi | 88% | 3045 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 92% | 57,841 psi | 89% | 3281 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,826 psi | 58% | 2031 fps | 100% |
| IMR 4350 | <<locked>> | 82% | 58,769 psi | 90% | 3114 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 86% | 58,233 psi | 90% | 3120 fps | 99.5% |
| IMR 7828 SSC | <<locked>> | 88% | 57,856 psi | 89% | 3202 fps | 99.7% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 56,623 psi | 87% | 3192 fps | 99.8% |
| Lovex S071 | <<locked>> | 92% | 57,624 psi | 89% | 3081 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 57,899 psi | 89% | 3215 fps | 100% |
| Norma MRP | <<locked>> | 84% | 56,159 psi | 86% | 3163 fps | 100% |
| Ramshot Grand | <<locked>> | 86% | 55,172 psi | 85% | 3159 fps | 99.7% |
| Ramshot Magnum | <<locked>> | 90% | 57,827 psi | 89% | 3150 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,740 psi | 60% | 2077 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 90% | 54,824 psi | 84% | 3202 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 94% | 58,189 psi | 90% | 3228 fps | 99.3% |
| Rottweil R 904 | <<locked>> | 84% | 57,276 psi | 88% | 3110 fps | 99.6% |
| Rottweil R 905 | <<locked>> | 84% | 56,173 psi | 86% | 3120 fps | 99.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 84% | 55,825 psi | 86% | 3117 fps | 99.9% |
| Somchem S361 | <<locked>> | 84% | 58,653 psi | 90% | 3097 fps | 99.5% |
| Somchem S385 | <<locked>> | 84% | 56,521 psi | 87% | 3091 fps | 100% |
| Vihtavuori N165 | <<locked>> | 88% | 56,623 psi | 87% | 3077 fps | 100% |
| Vihtavuori N170 | <<locked>> | 92% | 55,782 psi | 86% | 3091 fps | 96% |
| Vihtavuori N555 | <<locked>> | 84% | 56,028 psi | 86% | 3087 fps | 100% |
| Vihtavuori N560 | <<locked>> | 84% | 55,506 psi | 85% | 3166 fps | 99.2% |
| Vihtavuori N565 | <<locked>> | 90% | 56,739 psi | 87% | 3159 fps | 99.5% |
| Vihtavuori N568 | <<locked>> | 94% | 58,537 psi | 90% | 3232 fps | 99% |
| Vihtavuori N570 | <<locked>> | 94% | 55,927 psi | 86% | 3228 fps | 97.1% |
| Winchester StaBALL HD | <<locked>> | 86% | 54,418 psi | 84% | 3143 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 86% | 56,275 psi | 87% | 3084 fps | 99.9% |
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% | 45,600 psi | 70% | 2874 fps | 99.9% |
| Accurate MAGPRO | <<locked>> | 80% | 47,529 psi | 73% | 3009 fps | 97.2% |
| ADI AR 2209 | <<locked>> | 80% | 49,545 psi | 76% | 3012 fps | 99.3% |
| ADI AR 2213 | <<locked>> | 80% | 44,846 psi | 69% | 2949 fps | 97.7% |
| ADI AR 2217 | <<locked>> | 82% | 35,839 psi | 55% | 2730 fps | 95% |
| ADI AR 2218 | <<locked>> | 94% | 47,369 psi | 73% | 3077 fps | 95.1% |
| ADI AR 2225 | <<locked>> | 80% | 30,879 psi | 48% | 2625 fps | 95.8% |
| Alliant Reloder-19 | <<locked>> | 80% | 49,501 psi | 76% | 3005 fps | 99.4% |
| Alliant Reloder-22 | <<locked>> | 80% | 45,614 psi | 70% | 2953 fps | 98.8% |
| Alliant Reloder-23 | <<locked>> | 80% | 44,512 psi | 69% | 2890 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 38,580 psi | 59% | 2818 fps | 99.6% |
| Alliant Reloder-26 | <<locked>> | 80% | 50,763 psi | 78% | 3071 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 92% | 48,950 psi | 75% | 3071 fps | 95.7% |
| Alliant Reloder-50 | <<locked>> | 96% | 48,936 psi | 75% | 3058 fps | 95.1% |
| Baschieri & Pellagri 109 | <<locked>> | 82% | 45,948 psi | 71% | 2917 fps | 95.3% |
| Bofors RP15 | <<locked>> | 80% | 42,540 psi | 65% | 2884 fps | 98% |
| Bofors RP30 | <<locked>> | 80% | 36,100 psi | 56% | 2746 fps | 95.2% |
| Bofors RP5 | <<locked>> | 80% | 45,614 psi | 70% | 2953 fps | 98.8% |
| Hodgdon H1000 | <<locked>> | 80% | 36,492 psi | 56% | 2749 fps | 96% |
| Hodgdon H4831 | <<locked>> | 80% | 47,456 psi | 73% | 2953 fps | 97.7% |
| Hodgdon H4831 SC | <<locked>> | 80% | 46,514 psi | 72% | 2933 fps | 97.5% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 53,388 psi | 82% | 2992 fps | 100% |
| Hodgdon Retumbo | 67.1 gr | 80% | 37,768 psi | 58% | 2864 fps | 97.6% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,442 psi | 44% | 1821 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 55,071 psi | 85% | 3054 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 48,051 psi | 74% | 2936 fps | 98% |
| IMR 7828 SSC | <<locked>> | 80% | 43,714 psi | 67% | 2930 fps | 97.4% |
| IMR 8133 Enduron | <<locked>> | 88% | 37,550 psi | 58% | 2799 fps | 95.6% |
| Lovex S071 | <<locked>> | 80% | 39,334 psi | 61% | 2740 fps | 99.2% |
| Norma 217 | <<locked>> | 84% | 33,040 psi | 51% | 2694 fps | 96% |
| Norma MRP | <<locked>> | 80% | 48,675 psi | 75% | 3031 fps | 99.8% |
| Ramshot Grand | <<locked>> | 80% | 44,005 psi | 68% | 2943 fps | 97.8% |
| Ramshot Magnum | <<locked>> | 80% | 39,711 psi | 61% | 2808 fps | 98.2% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,153 psi | 45% | 1860 fps | 100% |
| ReloadSwiss RS 76 | 71.8 gr | 80% | 37,217 psi | 57% | 2838 fps | 98.5% |
| ReloadSwiss RS 80 | <<locked>> | 86% | 43,018 psi | 66% | 2933 fps | 96.1% |
| Rottweil R 904 | <<locked>> | 80% | 50,299 psi | 77% | 2989 fps | 98.8% |
| Rottweil R 905 | <<locked>> | 80% | 49,197 psi | 76% | 2995 fps | 99.4% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 48,849 psi | 75% | 2989 fps | 99.3% |
| Somchem S361 | <<locked>> | 80% | 51,430 psi | 79% | 2972 fps | 98.5% |
| Somchem S385 | <<locked>> | 80% | 49,516 psi | 76% | 2966 fps | 99.8% |
| Vihtavuori N165 | <<locked>> | 80% | 43,410 psi | 67% | 2835 fps | 98.8% |
| Vihtavuori N170 | <<locked>> | 90% | 52,199 psi | 80% | 3025 fps | 95.1% |
| Vihtavuori N555 | <<locked>> | 80% | 49,139 psi | 76% | 2972 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 48,225 psi | 74% | 3028 fps | 98% |
| Vihtavuori N565 | <<locked>> | 80% | 40,219 psi | 62% | 2825 fps | 95.9% |
| Vihtavuori N568 | <<locked>> | 86% | 43,932 psi | 68% | 2949 fps | 95.8% |
| Vihtavuori N570 | 78.3 gr | 90% | 48,356 psi | 74% | 3077 fps | 95% |
| Winchester StaBALL HD | <<locked>> | 80% | 43,424 psi | 67% | 2953 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 45,759 psi | 70% | 2894 fps | 98.8% |
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 .264 | 125gr | Hasler ARIETE. Hodgdon Retumbo delivers the highest muzzle velocity at 3,281 fps; across all powders the maximum-charge window runs from 2,031 fps to 3,281 fps. Alliant Reloder-50 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 125.0 gr projectile in 0.264" calls for a 1:8.0 twist; slower twists will usually not stabilise this weight. Alliant Reloder-50, Hodgdon TrailBoss, IMR 8133 Enduron 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. Vihtavuori N570, Hodgdon Retumbo, ReloadSwiss RS 76 rank at the top here: for 6.5-300 Weatherby Mag. with the .264 | 125gr | Hasler ARIETE 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.