Load Specifications
Load data in caliber 6.5-300 Weatherby Mag. with .264 | 123gr | Sierra MatchKing 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, ReloadSwiss RS 76 and ADI AR 2218.
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% | 56,478 psi | 87% | 3084 fps | 100% |
| Accurate High Country | <<locked>> | 84% | 58,494 psi | 90% | 3245 fps | 99.7% |
| Accurate MAGPRO | <<locked>> | 84% | 55,535 psi | 85% | 3182 fps | 98.8% |
| ADI AR 2209 | <<locked>> | 84% | 57,377 psi | 88% | 3173 fps | 99.9% |
| ADI AR 2213 | <<locked>> | 86% | 56,144 psi | 86% | 3186 fps | 99.5% |
| ADI AR 2217 | <<locked>> | 94% | 55,187 psi | 85% | 3163 fps | 99.7% |
| ADI AR 2218 | <<locked>> | 98% | 55,767 psi | 86% | 3278 fps | 97.7% |
| ADI AR 2225 | <<locked>> | 98% | 58,436 psi | 90% | 3245 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 84% | 56,985 psi | 88% | 3159 fps | 99.9% |
| Alliant Reloder-22 | <<locked>> | 86% | 56,652 psi | 87% | 3182 fps | 99.9% |
| Alliant Reloder-23 | <<locked>> | 88% | 58,407 psi | 90% | 3140 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 90% | 55,245 psi | 85% | 3159 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 82% | 55,405 psi | 85% | 3169 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 96% | 57,841 psi | 89% | 3255 fps | 97.8% |
| Alliant Reloder-50ᴾ | <<locked>> | 100% | 57,754 psi | 89% | 3241 fps | 97.3% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 56,362 psi | 87% | 3136 fps | 97.8% |
| Bofors RP15 | <<locked>> | 88% | 55,869 psi | 86% | 3166 fps | 99.9% |
| Bofors RP30 | <<locked>> | 92% | 55,317 psi | 85% | 3176 fps | 99.7% |
| Bofors RP5 | <<locked>> | 86% | 56,652 psi | 87% | 3182 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 92% | 56,579 psi | 87% | 3182 fps | 99.9% |
| Hodgdon H4831 | <<locked>> | 86% | 58,639 psi | 90% | 3176 fps | 99.4% |
| Hodgdon H4831 SC | <<locked>> | 86% | 57,740 psi | 89% | 3163 fps | 99.3% |
| Hodgdon Hybrid 100V | <<locked>> | 82% | 57,580 psi | 89% | 3077 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 92% | 58,740 psi | 90% | 3317 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,913 psi | 58% | 2054 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 84% | 55,201 psi | 85% | 3091 fps | 99.2% |
| IMR 7828 SSC | <<locked>> | 88% | 58,494 psi | 90% | 3232 fps | 99.7% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 57,290 psi | 88% | 3222 fps | 99.8% |
| Lovex S071 | <<locked>> | 92% | 58,276 psi | 90% | 3114 fps | 100% |
| Norma 217 | <<locked>> | 98% | 54,882 psi | 84% | 3186 fps | 100% |
| Norma MRP | <<locked>> | 84% | 56,797 psi | 87% | 3196 fps | 100% |
| Ramshot Grand | <<locked>> | 86% | 55,854 psi | 86% | 3189 fps | 99.7% |
| Ramshot Magnum | <<locked>> | 90% | 58,566 psi | 90% | 3179 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,812 psi | 60% | 2100 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 90% | 55,535 psi | 85% | 3232 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 92% | 54,824 psi | 84% | 3189 fps | 98.8% |
| Rottweil R 904 | <<locked>> | 84% | 57,537 psi | 89% | 3136 fps | 99.6% |
| Rottweil R 905 | <<locked>> | 84% | 56,695 psi | 87% | 3150 fps | 99.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 84% | 56,376 psi | 87% | 3146 fps | 99.9% |
| Somchem S361 | <<locked>> | 82% | 55,390 psi | 85% | 3064 fps | 99.1% |
| Somchem S385 | <<locked>> | 84% | 56,971 psi | 88% | 3117 fps | 100% |
| Vihtavuori N165 | <<locked>> | 88% | 57,246 psi | 88% | 3107 fps | 100% |
| Vihtavuori N170 | <<locked>> | 92% | 56,594 psi | 87% | 3123 fps | 96.1% |
| Vihtavuori N555 | <<locked>> | 84% | 56,623 psi | 87% | 3117 fps | 100% |
| Vihtavuori N560 | <<locked>> | 84% | 56,144 psi | 86% | 3199 fps | 99.2% |
| Vihtavuori N565 | <<locked>> | 90% | 57,232 psi | 88% | 3189 fps | 99.5% |
| Vihtavuori N568 | <<locked>> | 92% | 55,274 psi | 85% | 3196 fps | 98.5% |
| Vihtavuori N570 | <<locked>> | 94% | 56,550 psi | 87% | 3258 fps | 97.2% |
| Winchester StaBALL HD | <<locked>> | 86% | 55,187 psi | 85% | 3176 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 86% | 56,869 psi | 88% | 3114 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% | 46,151 psi | 71% | 2904 fps | 99.9% |
| Accurate High Country | <<locked>> | 80% | 50,720 psi | 78% | 3104 fps | 98.8% |
| Accurate MAGPRO | <<locked>> | 80% | 47,993 psi | 74% | 3038 fps | 97.3% |
| ADI AR 2209 | <<locked>> | 80% | 50,140 psi | 77% | 3041 fps | 99.4% |
| ADI AR 2213 | <<locked>> | 80% | 45,397 psi | 70% | 2979 fps | 97.7% |
| ADI AR 2217 | <<locked>> | 82% | 36,289 psi | 56% | 2756 fps | 95.1% |
| ADI AR 2218 | 85.2 gr | 94% | 48,051 psi | 74% | 3114 fps | 95.3% |
| ADI AR 2225 | <<locked>> | 80% | 31,154 psi | 48% | 2648 fps | 95.9% |
| Alliant Reloder-19 | <<locked>> | 80% | 50,024 psi | 77% | 3035 fps | 99.4% |
| Alliant Reloder-22 | <<locked>> | 80% | 46,180 psi | 71% | 2982 fps | 98.8% |
| Alliant Reloder-23 | <<locked>> | 80% | 44,918 psi | 69% | 2917 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 39,088 psi | 60% | 2848 fps | 99.7% |
| Alliant Reloder-26 | <<locked>> | 80% | 51,503 psi | 79% | 3104 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 92% | 49,690 psi | 76% | 3104 fps | 95.8% |
| Alliant Reloder-50 | <<locked>> | 96% | 49,661 psi | 76% | 3087 fps | 95.2% |
| Baschieri & Pellagri 109 | <<locked>> | 82% | 46,296 psi | 71% | 2943 fps | 95.3% |
| Bofors RP15 | <<locked>> | 80% | 42,931 psi | 66% | 2910 fps | 98.1% |
| Bofors RP30 | <<locked>> | 80% | 36,608 psi | 56% | 2772 fps | 95.2% |
| Bofors RP5 | <<locked>> | 80% | 46,180 psi | 71% | 2982 fps | 98.8% |
| Hodgdon H1000 | <<locked>> | 80% | 36,796 psi | 57% | 2772 fps | 96% |
| Hodgdon H4831 | <<locked>> | 80% | 47,776 psi | 74% | 2979 fps | 97.8% |
| Hodgdon H4831 SC | <<locked>> | 80% | 47,007 psi | 72% | 2963 fps | 97.6% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 53,853 psi | 83% | 3022 fps | 100% |
| Hodgdon Retumbo | 68.4 gr | 80% | 38,130 psi | 59% | 2890 fps | 97.7% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,369 psi | 44% | 1837 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 48,573 psi | 75% | 2966 fps | 98.1% |
| IMR 7828 SSC | <<locked>> | 80% | 44,063 psi | 68% | 2956 fps | 97.4% |
| IMR 8133 Enduron | <<locked>> | 88% | 37,956 psi | 58% | 2822 fps | 95.6% |
| Lovex S071 | <<locked>> | 80% | 39,769 psi | 61% | 2769 fps | 99.2% |
| Norma 217 | <<locked>> | 84% | 33,533 psi | 52% | 2720 fps | 96.1% |
| Norma MRP | <<locked>> | 80% | 49,197 psi | 76% | 3058 fps | 99.8% |
| Ramshot Grand | <<locked>> | 80% | 44,556 psi | 69% | 2972 fps | 97.9% |
| Ramshot Magnum | <<locked>> | 80% | 40,176 psi | 62% | 2835 fps | 98.3% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,225 psi | 45% | 1883 fps | 100% |
| ReloadSwiss RS 76 | 73.2 gr | 80% | 37,608 psi | 58% | 2861 fps | 98.5% |
| ReloadSwiss RS 80 | <<locked>> | 86% | 43,685 psi | 67% | 2963 fps | 96.2% |
| Rottweil R 904 | <<locked>> | 80% | 50,676 psi | 78% | 3012 fps | 98.8% |
| Rottweil R 905 | <<locked>> | 80% | 49,588 psi | 76% | 3025 fps | 99.4% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 49,240 psi | 76% | 3018 fps | 99.3% |
| Somchem S361 | <<locked>> | 80% | 51,808 psi | 80% | 3002 fps | 98.6% |
| Somchem S385 | <<locked>> | 80% | 50,038 psi | 77% | 2999 fps | 99.8% |
| Vihtavuori N165 | <<locked>> | 80% | 43,903 psi | 68% | 2864 fps | 98.9% |
| Vihtavuori N170 | <<locked>> | 90% | 52,808 psi | 81% | 3054 fps | 95.1% |
| Vihtavuori N555 | <<locked>> | 80% | 49,559 psi | 76% | 3002 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 48,718 psi | 75% | 3054 fps | 98% |
| Vihtavuori N565 | <<locked>> | 80% | 40,698 psi | 63% | 2854 fps | 96% |
| Vihtavuori N568 | <<locked>> | 86% | 44,469 psi | 68% | 2979 fps | 95.9% |
| Vihtavuori N570 | <<locked>> | 90% | 49,037 psi | 75% | 3110 fps | 95.1% |
| Winchester StaBALL HD | <<locked>> | 80% | 44,048 psi | 68% | 2982 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 46,238 psi | 71% | 2920 fps | 98.9% |
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 50 powders for 6.5-300 Weatherby Mag. loaded with the .264 | 123gr | Sierra MatchKing. Hodgdon Retumbo delivers the highest muzzle velocity at 3,317 fps; across all powders the maximum-charge window runs from 2,054 fps to 3,317 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 123.0 gr projectile in 0.264" calls for a 1:9.0 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. Hodgdon Retumbo, ReloadSwiss RS 76, ADI AR 2218 rank at the top here: for 6.5-300 Weatherby Mag. with the .264 | 123gr | Sierra MatchKing 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.