Load Specifications
Load data in caliber 6.5-300 Weatherby Mag. with .264 | 125gr | SUS-TAC HPT bullet and 51 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% | 55,492 psi | 85% | 3048 fps | 100% |
| Accurate High Country | <<locked>> | 84% | 57,479 psi | 88% | 3209 fps | 99.7% |
| Accurate MAGPRO | <<locked>> | 86% | 58,465 psi | 90% | 3219 fps | 99.2% |
| ADI AR 2209 | <<locked>> | 84% | 56,594 psi | 87% | 3136 fps | 99.9% |
| ADI AR 2213 | <<locked>> | 86% | 55,158 psi | 85% | 3150 fps | 99.4% |
| ADI AR 2217 | <<locked>> | 96% | 58,233 psi | 90% | 3192 fps | 99.9% |
| ADI AR 2218 | <<locked>> | 98% | 54,665 psi | 84% | 3238 fps | 97.4% |
| ADI AR 2225 | <<locked>> | 98% | 57,246 psi | 88% | 3212 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 84% | 56,246 psi | 87% | 3127 fps | 99.9% |
| Alliant Reloder-22 | <<locked>> | 86% | 55,724 psi | 86% | 3146 fps | 99.9% |
| Alliant Reloder-23 | <<locked>> | 88% | 57,638 psi | 89% | 3110 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 92% | 58,218 psi | 90% | 3186 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 84% | 58,639 psi | 90% | 3199 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 96% | 56,623 psi | 87% | 3222 fps | 97.6% |
| Alliant Reloder-50ᴾ | <<locked>> | 100% | 56,420 psi | 87% | 3202 fps | 97.1% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 55,724 psi | 86% | 3107 fps | 97.7% |
| Bofors RP15 | <<locked>> | 90% | 58,769 psi | 90% | 3192 fps | 100% |
| Bofors RP30 | <<locked>> | 94% | 58,117 psi | 89% | 3202 fps | 99.9% |
| Bofors RP5 | <<locked>> | 86% | 55,724 psi | 86% | 3146 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 92% | 55,738 psi | 86% | 3153 fps | 99.9% |
| Hodgdon H4831 | <<locked>> | 86% | 57,986 psi | 89% | 3146 fps | 99.4% |
| Hodgdon H4831 SC | <<locked>> | 86% | 56,840 psi | 87% | 3127 fps | 99.3% |
| Hodgdon Hybrid 100V | <<locked>> | 82% | 56,884 psi | 88% | 3045 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 92% | 57,508 psi | 89% | 3278 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,826 psi | 58% | 2031 fps | 100% |
| IMR 4350 | <<locked>> | 82% | 58,479 psi | 90% | 3110 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 86% | 57,943 psi | 89% | 3117 fps | 99.5% |
| IMR 7828 SSC | <<locked>> | 88% | 57,551 psi | 89% | 3196 fps | 99.7% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 56,362 psi | 87% | 3189 fps | 99.7% |
| Lovex S071 | <<locked>> | 92% | 57,537 psi | 89% | 3077 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 57,624 psi | 89% | 3212 fps | 100% |
| Norma MRP | <<locked>> | 84% | 55,840 psi | 86% | 3159 fps | 100% |
| Ramshot Grand | <<locked>> | 86% | 54,853 psi | 84% | 3153 fps | 99.6% |
| Ramshot Magnum | <<locked>> | 90% | 57,551 psi | 89% | 3146 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,754 psi | 60% | 2077 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 92% | 58,697 psi | 90% | 3264 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 94% | 57,957 psi | 89% | 3228 fps | 99.3% |
| Rottweil R 904 | <<locked>> | 84% | 57,000 psi | 88% | 3107 fps | 99.6% |
| Rottweil R 905 | <<locked>> | 84% | 55,898 psi | 86% | 3117 fps | 99.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 84% | 55,521 psi | 85% | 3110 fps | 99.9% |
| Somchem S361 | <<locked>> | 84% | 58,421 psi | 90% | 3094 fps | 99.4% |
| Somchem S385 | <<locked>> | 84% | 56,231 psi | 87% | 3084 fps | 100% |
| Vihtavuori N165 | <<locked>> | 88% | 56,376 psi | 87% | 3074 fps | 100% |
| Vihtavuori N170 | <<locked>> | 92% | 55,564 psi | 86% | 3087 fps | 95.9% |
| Vihtavuori N555 | <<locked>> | 84% | 55,724 psi | 86% | 3084 fps | 100% |
| Vihtavuori N560 | <<locked>> | 84% | 55,201 psi | 85% | 3159 fps | 99.2% |
| Vihtavuori N565 | <<locked>> | 90% | 56,463 psi | 87% | 3156 fps | 99.4% |
| Vihtavuori N568 | <<locked>> | 94% | 58,291 psi | 90% | 3232 fps | 99% |
| Vihtavuori N570 | <<locked>> | 94% | 55,637 psi | 86% | 3225 fps | 97% |
| Winchester StaBALL HD | <<locked>> | 88% | 58,465 psi | 90% | 3205 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 86% | 56,202 psi | 86% | 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% | 45,498 psi | 70% | 2874 fps | 99.9% |
| Accurate High Country | <<locked>> | 80% | 49,922 psi | 77% | 3071 fps | 98.8% |
| Accurate MAGPRO | <<locked>> | 80% | 47,253 psi | 73% | 3005 fps | 97.2% |
| ADI AR 2209 | <<locked>> | 80% | 49,487 psi | 76% | 3012 fps | 99.3% |
| ADI AR 2213 | <<locked>> | 80% | 44,744 psi | 69% | 2946 fps | 97.6% |
| ADI AR 2217 | <<locked>> | 84% | 38,247 psi | 59% | 2792 fps | 96% |
| ADI AR 2218 | <<locked>> | 94% | 47,181 psi | 73% | 3074 fps | 95% |
| ADI AR 2225 | <<locked>> | 80% | 30,690 psi | 47% | 2618 fps | 95.7% |
| Alliant Reloder-19 | <<locked>> | 80% | 49,400 psi | 76% | 3002 fps | 99.3% |
| Alliant Reloder-22 | <<locked>> | 80% | 45,527 psi | 70% | 2953 fps | 98.8% |
| Alliant Reloder-23 | <<locked>> | 80% | 44,222 psi | 68% | 2887 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 38,464 psi | 59% | 2818 fps | 99.6% |
| Alliant Reloder-26 | <<locked>> | 80% | 50,444 psi | 78% | 3068 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 92% | 48,675 psi | 75% | 3064 fps | 95.6% |
| Alliant Reloder-50 | <<locked>> | 98% | 52,286 psi | 80% | 3127 fps | 96.1% |
| Baschieri & Pellagri 109 | <<locked>> | 82% | 45,716 psi | 70% | 2913 fps | 95.2% |
| Bofors RP15 | <<locked>> | 80% | 42,293 psi | 65% | 2877 fps | 98% |
| Bofors RP30 | <<locked>> | 80% | 36,013 psi | 55% | 2743 fps | 95.1% |
| Bofors RP5 | <<locked>> | 80% | 45,527 psi | 70% | 2953 fps | 98.8% |
| Hodgdon H1000 | <<locked>> | 80% | 36,260 psi | 56% | 2746 fps | 95.9% |
| Hodgdon H4831 | <<locked>> | 80% | 47,224 psi | 73% | 2946 fps | 97.7% |
| Hodgdon H4831 SC | <<locked>> | 80% | 46,441 psi | 71% | 2933 fps | 97.5% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 53,301 psi | 82% | 2992 fps | 100% |
| Hodgdon Retumbo | 66.8 gr | 80% | 37,536 psi | 58% | 2858 fps | 97.5% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,413 psi | 44% | 1818 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 54,998 psi | 85% | 3051 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 47,993 psi | 74% | 2936 fps | 98% |
| IMR 7828 SSC | <<locked>> | 80% | 43,410 psi | 67% | 2927 fps | 97.3% |
| IMR 8133 Enduron | <<locked>> | 88% | 37,318 psi | 57% | 2792 fps | 95.5% |
| Lovex S071 | <<locked>> | 80% | 39,088 psi | 60% | 2736 fps | 99.2% |
| Norma 217 | <<locked>> | 84% | 32,779 psi | 50% | 2687 fps | 95.9% |
| Norma MRP | <<locked>> | 80% | 48,399 psi | 74% | 3028 fps | 99.8% |
| Ramshot Grand | <<locked>> | 80% | 43,903 psi | 68% | 2943 fps | 97.8% |
| Ramshot Magnum | <<locked>> | 80% | 39,450 psi | 61% | 2805 fps | 98.2% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,124 psi | 45% | 1860 fps | 100% |
| ReloadSwiss RS 76 | 71.5 gr | 80% | 36,970 psi | 57% | 2831 fps | 98.4% |
| ReloadSwiss RS 80 | <<locked>> | 86% | 42,757 psi | 66% | 2930 fps | 96% |
| Rottweil R 904 | <<locked>> | 80% | 50,053 psi | 77% | 2982 fps | 98.8% |
| Rottweil R 905 | <<locked>> | 80% | 48,907 psi | 75% | 2989 fps | 99.4% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 48,573 psi | 75% | 2986 fps | 99.3% |
| Somchem S361 | <<locked>> | 80% | 51,198 psi | 79% | 2969 fps | 98.5% |
| Somchem S385 | <<locked>> | 80% | 49,429 psi | 76% | 2966 fps | 99.7% |
| Vihtavuori N165 | <<locked>> | 80% | 43,323 psi | 67% | 2835 fps | 98.8% |
| Vihtavuori N170 | <<locked>> | 90% | 51,982 psi | 80% | 3022 fps | 95% |
| Vihtavuori N555 | <<locked>> | 80% | 49,023 psi | 75% | 2972 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 47,964 psi | 74% | 3022 fps | 97.9% |
| Vihtavuori N565 | <<locked>> | 80% | 40,147 psi | 62% | 2825 fps | 95.9% |
| Vihtavuori N568 | <<locked>> | 86% | 43,685 psi | 67% | 2946 fps | 95.7% |
| Vihtavuori N570 | 79.7 gr | 92% | 51,619 psi | 79% | 3146 fps | 96% |
| Winchester StaBALL HD | <<locked>> | 80% | 43,091 psi | 66% | 2946 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 45,672 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 51 powders for 6.5-300 Weatherby Mag. loaded with the .264 | 125gr | SUS-TAC HPT. Hodgdon Retumbo delivers the highest muzzle velocity at 3,278 fps; across all powders the maximum-charge window runs from 2,031 fps to 3,278 fps. Alliant Reloder-50 gives the best case fill at 100 %, and 51 of the 51 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 | SUS-TAC HPT 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.