Load Specifications
Load data in caliber .30-378 Weath. Mag. with .308 | 178gr | Remington SP Extended-Range bullet and 51 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: 26"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 84% | 55,419 psi | 87% | 3038 fps | 100% |
| Accurate 8700ᴾ | <<locked>> | 100% | 51,227 psi | 80% | 3064 fps | 97.3% |
| Accurate High Country | <<locked>> | 82% | 57,551 psi | 90% | 3209 fps | 100% |
| Accurate MAGPRO | <<locked>> | 82% | 54,636 psi | 86% | 3150 fps | 99.4% |
| ADI AR 2209 | <<locked>> | 82% | 56,275 psi | 88% | 3127 fps | 100% |
| ADI AR 2213 | <<locked>> | 84% | 55,114 psi | 86% | 3143 fps | 99.9% |
| ADI AR 2217 | <<locked>> | 92% | 54,549 psi | 85% | 3127 fps | 100% |
| ADI AR 2218 | <<locked>> | 96% | 55,129 psi | 86% | 3255 fps | 98.8% |
| ADI AR 2225 | <<locked>> | 94% | 54,389 psi | 85% | 3156 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 82% | 56,463 psi | 88% | 3123 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 82% | 55,898 psi | 88% | 3117 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 84% | 55,695 psi | 87% | 3140 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 84% | 54,114 psi | 85% | 3041 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 88% | 54,882 psi | 86% | 3123 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 94% | 57,348 psi | 90% | 3232 fps | 98.8% |
| Alliant Reloder-50 | <<locked>> | 98% | 57,566 psi | 90% | 3225 fps | 98.5% |
| Baschieri & Pellagri 109 | <<locked>> | 86% | 55,434 psi | 87% | 3104 fps | 98.7% |
| Bofors RP15 | <<locked>> | 86% | 55,230 psi | 87% | 3130 fps | 100% |
| Bofors RP30 | <<locked>> | 90% | 54,781 psi | 86% | 3143 fps | 100% |
| Bofors RP5 | <<locked>> | 84% | 55,695 psi | 87% | 3140 fps | 100% |
| Hodgdon H1000 | <<locked>> | 90% | 55,956 psi | 88% | 3146 fps | 100% |
| Hodgdon H4831 | <<locked>> | 84% | 57,479 psi | 90% | 3133 fps | 99.8% |
| Hodgdon H4831 SC | <<locked>> | 84% | 56,536 psi | 89% | 3117 fps | 99.8% |
| Hodgdon Retumbo | <<locked>> | 88% | 54,389 psi | 85% | 3215 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 38,000 psi | 60% | 2034 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 84% | 57,551 psi | 90% | 3107 fps | 99.9% |
| IMR 7828 SSC | <<locked>> | 86% | 57,595 psi | 90% | 3192 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 90% | 56,246 psi | 88% | 3058 fps | 95.9% |
| IMR 8133 Enduron | <<locked>> | 98% | 57,029 psi | 89% | 3192 fps | 100% |
| Lovex S071 | <<locked>> | 90% | 57,508 psi | 90% | 3068 fps | 100% |
| Norma 217 | <<locked>> | 96% | 54,810 psi | 86% | 3159 fps | 100% |
| Norma MRP | <<locked>> | 82% | 55,927 psi | 88% | 3156 fps | 100% |
| Ramshot Grand | <<locked>> | 84% | 55,158 psi | 86% | 3153 fps | 100% |
| Ramshot Magnum | <<locked>> | 88% | 57,682 psi | 90% | 3140 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 39,088 psi | 61% | 2083 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 88% | 55,172 psi | 86% | 3199 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 90% | 54,331 psi | 85% | 3163 fps | 99.6% |
| Rottweil R 904 | <<locked>> | 82% | 56,420 psi | 88% | 3094 fps | 99.9% |
| Rottweil R 905 | <<locked>> | 82% | 55,796 psi | 87% | 3110 fps | 100% |
| SNPE Vectan SP 13ᴾ | <<locked>> | 100% | 52,997 psi | 83% | 3077 fps | 97.3% |
| SNPE Vectan Tubal 8000 | <<locked>> | 82% | 55,434 psi | 87% | 3104 fps | 100% |
| Somchem S385 | <<locked>> | 82% | 55,956 psi | 88% | 3074 fps | 100% |
| Vihtavuori N165 | <<locked>> | 86% | 56,217 psi | 88% | 3064 fps | 100% |
| Vihtavuori N170 | <<locked>> | 90% | 55,709 psi | 87% | 3091 fps | 97.3% |
| Vihtavuori N555 | <<locked>> | 82% | 55,709 psi | 87% | 3071 fps | 100% |
| Vihtavuori N560 | <<locked>> | 82% | 55,216 psi | 87% | 3159 fps | 99.7% |
| Vihtavuori N565 | <<locked>> | 88% | 56,608 psi | 89% | 3156 fps | 99.9% |
| Vihtavuori N568 | <<locked>> | 90% | 54,737 psi | 86% | 3166 fps | 99.3% |
| Vihtavuori N570 | <<locked>> | 92% | 56,289 psi | 88% | 3238 fps | 98.4% |
| Winchester StaBALL HD | <<locked>> | 84% | 54,897 psi | 86% | 3136 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 84% | 55,840 psi | 88% | 3071 fps | 100% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 26"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 80% | 48,457 psi | 76% | 2923 fps | 100% |
| Accurate 8700 | <<locked>> | 96% | 44,077 psi | 69% | 2923 fps | 95.2% |
| Accurate High Country | <<locked>> | 80% | 53,563 psi | 84% | 3136 fps | 99.8% |
| Accurate MAGPRO | <<locked>> | 80% | 50,894 psi | 80% | 3081 fps | 99% |
| ADI AR 2209 | <<locked>> | 80% | 52,533 psi | 82% | 3064 fps | 100% |
| ADI AR 2213 | <<locked>> | 80% | 47,935 psi | 75% | 3012 fps | 99.2% |
| ADI AR 2217 | <<locked>> | 80% | 35,766 psi | 56% | 2736 fps | 96.6% |
| ADI AR 2218 | 112.3 gr | 90% | 44,063 psi | 69% | 3018 fps | 95.8% |
| ADI AR 2225 | <<locked>> | 80% | 33,185 psi | 52% | 2710 fps | 98.5% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 52,765 psi | 83% | 3061 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 52,272 psi | 82% | 3054 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 80% | 48,704 psi | 76% | 3015 fps | 99.8% |
| Alliant Reloder-23 | <<locked>> | 80% | 47,369 psi | 74% | 2933 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 41,524 psi | 65% | 2884 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 86% | 42,424 psi | 66% | 2936 fps | 95.1% |
| Alliant Reloder-50 | <<locked>> | 92% | 46,006 psi | 72% | 3002 fps | 95.8% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 45,411 psi | 71% | 2910 fps | 96.5% |
| Bofors RP15 | <<locked>> | 80% | 45,266 psi | 71% | 2946 fps | 99.4% |
| Bofors RP30 | <<locked>> | 80% | 38,798 psi | 61% | 2818 fps | 97.6% |
| Bofors RP5 | <<locked>> | 80% | 48,704 psi | 76% | 3015 fps | 99.8% |
| Hodgdon H1000 | <<locked>> | 80% | 39,044 psi | 61% | 2822 fps | 98.3% |
| Hodgdon H4831 | <<locked>> | 80% | 50,270 psi | 79% | 3009 fps | 99.2% |
| Hodgdon H4831 SC | <<locked>> | 80% | 49,414 psi | 77% | 2992 fps | 99% |
| Hodgdon Retumbo | 94.3 gr | 80% | 40,727 psi | 64% | 2946 fps | 99.5% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,558 psi | 45% | 1821 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 50,618 psi | 79% | 2989 fps | 99.3% |
| IMR 7828 SSC | <<locked>> | 80% | 46,789 psi | 73% | 2995 fps | 99.1% |
| IMR 7977 Enduron | <<locked>> | 88% | 52,736 psi | 83% | 2995 fps | 95% |
| IMR 8133 Enduron | <<locked>> | 82% | 32,982 psi | 52% | 2684 fps | 95.1% |
| Lovex S071 | <<locked>> | 80% | 41,901 psi | 66% | 2799 fps | 100% |
| Norma 217 | <<locked>> | 80% | 31,111 psi | 49% | 2644 fps | 96.7% |
| Norma MRP | <<locked>> | 80% | 52,054 psi | 82% | 3087 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 47,456 psi | 74% | 3015 fps | 99.4% |
| Ramshot Magnum | <<locked>> | 80% | 42,757 psi | 67% | 2877 fps | 99.6% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,341 psi | 46% | 1864 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 40,364 psi | 63% | 2920 fps | 99.9% |
| ReloadSwiss RS 80 | <<locked>> | 80% | 37,159 psi | 58% | 2802 fps | 95.4% |
| Rottweil R 904 | <<locked>> | 80% | 52,910 psi | 83% | 3035 fps | 99.7% |
| Rottweil R 905 | <<locked>> | 80% | 52,127 psi | 82% | 3045 fps | 100% |
| SNPE Vectan SP 13 | <<locked>> | 96% | 46,122 psi | 72% | 2943 fps | 95.4% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 51,779 psi | 81% | 3041 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 52,504 psi | 82% | 3018 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 46,006 psi | 72% | 2887 fps | 99.8% |
| Vihtavuori N170 | <<locked>> | 86% | 48,631 psi | 76% | 2963 fps | 95.6% |
| Vihtavuori N555 | <<locked>> | 80% | 52,214 psi | 82% | 3015 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 51,401 psi | 81% | 3091 fps | 99.4% |
| Vihtavuori N565 | <<locked>> | 80% | 43,120 psi | 68% | 2900 fps | 98.1% |
| Vihtavuori N568 | <<locked>> | 80% | 38,145 psi | 60% | 2822 fps | 95.2% |
| Vihtavuori N570 | 105.2 gr | 86% | 45,353 psi | 71% | 3022 fps | 95.7% |
| Winchester StaBALL HD | <<locked>> | 80% | 47,239 psi | 74% | 3012 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 48,646 psi | 76% | 2949 fps | 99.8% |
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 .30-378 Weath. Mag. loaded with the .308 | 178gr | Remington SP Extended-Range. ADI AR 2218 delivers the highest muzzle velocity at 3,255 fps; across all powders the maximum-charge window runs from 2,034 fps to 3,255 fps. Accurate 8700 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 (440 MPa), the top charges use 60–90 %, leaving at least 10 % headroom. The 178.0 gr projectile in 0.308" calls for a 1:6.0 twist; slower twists will usually not stabilise this weight. Accurate 8700, 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 .30-378 Weath. Mag. with the .308 | 178gr | Remington SP Extended-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.