Load Specifications
Load data in caliber 6.5-300 Weatherby Mag. with .264 | 128gr | MRR Green Long Range 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.
A valid access license is required to use the Personalized Load Calculator.
You can find more information in our FAQ: How can I use the Personalized Load Calculator?
Max Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 86% | 56,971 psi | 88% | 3041 fps | 100% |
| Accurate High Country | <<locked>> | 82% | 55,230 psi | 85% | 3136 fps | 99.6% |
| Accurate MAGPRO | <<locked>> | 84% | 56,144 psi | 86% | 3146 fps | 99.1% |
| ADI AR 2209 | <<locked>> | 84% | 58,001 psi | 89% | 3130 fps | 100% |
| ADI AR 2213 | <<locked>> | 86% | 56,695 psi | 87% | 3143 fps | 99.7% |
| ADI AR 2217 | <<locked>> | 94% | 55,970 psi | 86% | 3127 fps | 99.8% |
| ADI AR 2218 | <<locked>> | 98% | 56,405 psi | 87% | 3241 fps | 98.1% |
| ADI AR 2225 | <<locked>> | 96% | 55,419 psi | 85% | 3146 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 84% | 57,638 psi | 89% | 3120 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 86% | 57,203 psi | 88% | 3140 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 86% | 55,564 psi | 86% | 3045 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 90% | 56,130 psi | 86% | 3120 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 82% | 56,086 psi | 86% | 3127 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 96% | 58,523 psi | 90% | 3222 fps | 98.2% |
| Alliant Reloder-50ᴾ | <<locked>> | 100% | 58,610 psi | 90% | 3212 fps | 97.8% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 56,971 psi | 88% | 3100 fps | 98.2% |
| Bofors RP15 | <<locked>> | 88% | 56,637 psi | 87% | 3127 fps | 100% |
| Bofors RP30 | <<locked>> | 92% | 56,043 psi | 86% | 3136 fps | 99.8% |
| Bofors RP5 | <<locked>> | 86% | 57,203 psi | 88% | 3140 fps | 100% |
| Hodgdon H1000 | <<locked>> | 92% | 57,334 psi | 88% | 3146 fps | 100% |
| Hodgdon H4831 | <<locked>> | 84% | 55,535 psi | 85% | 3074 fps | 99.3% |
| Hodgdon H4831 SC | <<locked>> | 86% | 58,218 psi | 90% | 3117 fps | 99.5% |
| Hodgdon Hybrid 100V | <<locked>> | 82% | 58,305 psi | 90% | 3035 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 90% | 55,492 psi | 85% | 3212 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,840 psi | 58% | 2011 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 84% | 55,782 psi | 86% | 3051 fps | 99.4% |
| IMR 7828 SSC | <<locked>> | 86% | 55,376 psi | 85% | 3130 fps | 99.6% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 58,001 psi | 89% | 3186 fps | 99.9% |
| Lovex S071 | <<locked>> | 90% | 55,390 psi | 85% | 3015 fps | 100% |
| Norma 217 | <<locked>> | 98% | 55,622 psi | 86% | 3146 fps | 100% |
| Norma MRP | <<locked>> | 84% | 57,406 psi | 88% | 3153 fps | 100% |
| Ramshot Grand | <<locked>> | 86% | 56,521 psi | 87% | 3153 fps | 99.8% |
| Ramshot Magnum | <<locked>> | 88% | 55,114 psi | 85% | 3077 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,943 psi | 60% | 2060 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 90% | 56,347 psi | 87% | 3196 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 92% | 55,608 psi | 86% | 3156 fps | 99.2% |
| Rottweil R 904 | <<locked>> | 84% | 58,349 psi | 90% | 3097 fps | 99.8% |
| Rottweil R 905 | <<locked>> | 84% | 57,363 psi | 88% | 3110 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 84% | 56,985 psi | 88% | 3104 fps | 100% |
| Somchem S361 | <<locked>> | 82% | 56,043 psi | 86% | 3028 fps | 99.3% |
| Somchem S385 | <<locked>> | 84% | 57,624 psi | 89% | 3077 fps | 100% |
| Vihtavuori N165 | <<locked>> | 88% | 57,740 psi | 89% | 3064 fps | 100% |
| Vihtavuori N170 | <<locked>> | 92% | 57,087 psi | 88% | 3084 fps | 96.6% |
| Vihtavuori N555 | <<locked>> | 84% | 57,276 psi | 88% | 3074 fps | 100% |
| Vihtavuori N560 | <<locked>> | 84% | 56,739 psi | 87% | 3156 fps | 99.5% |
| Vihtavuori N565 | <<locked>> | 90% | 57,957 psi | 89% | 3150 fps | 99.7% |
| Vihtavuori N568 | <<locked>> | 92% | 55,956 psi | 86% | 3159 fps | 98.9% |
| Vihtavuori N570 | <<locked>> | 94% | 57,537 psi | 89% | 3225 fps | 97.7% |
| Winchester StaBALL HD | <<locked>> | 86% | 56,202 psi | 86% | 3136 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 86% | 57,609 psi | 89% | 3074 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% | 46,630 psi | 72% | 2864 fps | 100% |
| Accurate High Country | <<locked>> | 80% | 51,358 psi | 79% | 3068 fps | 99.2% |
| Accurate MAGPRO | <<locked>> | 80% | 48,646 psi | 75% | 3005 fps | 97.8% |
| ADI AR 2209 | <<locked>> | 80% | 50,821 psi | 78% | 3005 fps | 99.6% |
| ADI AR 2213 | <<locked>> | 80% | 45,905 psi | 71% | 2940 fps | 98.1% |
| ADI AR 2217 | <<locked>> | 82% | 36,695 psi | 56% | 2726 fps | 95.7% |
| ADI AR 2218 | 83.9 gr | 94% | 48,704 psi | 75% | 3084 fps | 96% |
| ADI AR 2225 | <<locked>> | 80% | 31,691 psi | 49% | 2625 fps | 96.7% |
| Alliant Reloder-19 | <<locked>> | 80% | 50,502 psi | 78% | 2992 fps | 99.6% |
| Alliant Reloder-22 | <<locked>> | 80% | 46,659 psi | 72% | 2946 fps | 99.2% |
| Alliant Reloder-23 | <<locked>> | 80% | 45,585 psi | 70% | 2881 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 39,769 psi | 61% | 2818 fps | 99.9% |
| Alliant Reloder-26 | <<locked>> | 80% | 52,054 psi | 80% | 3061 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 90% | 46,818 psi | 72% | 2999 fps | 95.3% |
| Alliant Reloder-50 | <<locked>> | 96% | 50,488 psi | 78% | 3061 fps | 95.8% |
| Baschieri & Pellagri 109 | <<locked>> | 82% | 46,818 psi | 72% | 2910 fps | 95.9% |
| Bofors RP15 | <<locked>> | 80% | 43,540 psi | 67% | 2877 fps | 98.5% |
| Bofors RP30 | <<locked>> | 80% | 37,072 psi | 57% | 2743 fps | 95.9% |
| Bofors RP5 | <<locked>> | 80% | 46,659 psi | 72% | 2946 fps | 99.2% |
| Hodgdon H1000 | <<locked>> | 80% | 37,391 psi | 58% | 2746 fps | 96.7% |
| Hodgdon H4831 | <<locked>> | 80% | 48,457 psi | 75% | 2943 fps | 98.2% |
| Hodgdon H4831 SC | <<locked>> | 80% | 47,500 psi | 73% | 2923 fps | 98% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 54,491 psi | 84% | 2976 fps | 100% |
| Hodgdon Retumbo | 67.4 gr | 80% | 38,827 psi | 60% | 2864 fps | 98.2% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,485 psi | 44% | 1801 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 49,153 psi | 76% | 2930 fps | 98.5% |
| IMR 7828 SSC | <<locked>> | 80% | 44,788 psi | 69% | 2927 fps | 97.9% |
| IMR 8133 Enduron | <<locked>> | 86% | 36,085 psi | 56% | 2733 fps | 95.2% |
| Lovex S071 | <<locked>> | 80% | 40,277 psi | 62% | 2733 fps | 99.5% |
| Norma 217 | <<locked>> | 82% | 31,633 psi | 49% | 2625 fps | 95.6% |
| Norma MRP | <<locked>> | 80% | 49,864 psi | 77% | 3022 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 45,194 psi | 70% | 2940 fps | 98.3% |
| Ramshot Magnum | <<locked>> | 80% | 40,770 psi | 63% | 2805 fps | 98.7% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,211 psi | 45% | 1844 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 38,261 psi | 59% | 2835 fps | 99% |
| ReloadSwiss RS 80 | <<locked>> | 84% | 40,988 psi | 63% | 2861 fps | 95.6% |
| Rottweil R 904 | <<locked>> | 80% | 51,271 psi | 79% | 2976 fps | 99.1% |
| Rottweil R 905 | <<locked>> | 80% | 50,256 psi | 77% | 2986 fps | 99.6% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 49,908 psi | 77% | 2979 fps | 99.6% |
| Somchem S361 | <<locked>> | 80% | 52,388 psi | 81% | 2966 fps | 98.9% |
| Somchem S385 | <<locked>> | 80% | 50,531 psi | 78% | 2956 fps | 99.9% |
| Vihtavuori N165 | <<locked>> | 80% | 44,353 psi | 68% | 2828 fps | 99.2% |
| Vihtavuori N170 | <<locked>> | 90% | 53,490 psi | 82% | 3025 fps | 95.7% |
| Vihtavuori N555 | <<locked>> | 80% | 50,256 psi | 77% | 2963 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 49,356 psi | 76% | 3018 fps | 98.4% |
| Vihtavuori N565 | <<locked>> | 80% | 41,249 psi | 63% | 2822 fps | 96.6% |
| Vihtavuori N568 | <<locked>> | 84% | 42,047 psi | 65% | 2877 fps | 95.4% |
| Vihtavuori N570 | 78.7 gr | 90% | 49,806 psi | 77% | 3081 fps | 95.8% |
| Winchester StaBALL HD | <<locked>> | 80% | 44,788 psi | 69% | 2943 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 46,717 psi | 72% | 2884 fps | 99.2% |
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 | 128gr | MRR Green Long Range. ADI AR 2218 delivers the highest muzzle velocity at 3,241 fps; across all powders the maximum-charge window runs from 2,011 fps to 3,241 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 128.0 gr projectile in 0.264" calls for a 1:8.5 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, ADI AR 2218, Vihtavuori N570 rank at the top here: for 6.5-300 Weatherby Mag. with the .264 | 128gr | MRR Green Long Range 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.