Load Specifications
Load data in caliber .30-378 Weath. Mag. with .308 | 166gr | Hammer Stone Hammer bullet and 54 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 80 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>> | 88% | 56,449 psi | 88% | 3150 fps | 100% |
| Accurate High Country | <<locked>> | 84% | 54,650 psi | 86% | 3255 fps | 99.6% |
| Accurate MAGPRO | <<locked>> | 86% | 55,753 psi | 87% | 3261 fps | 99.1% |
| ADI AR 2209 | <<locked>> | 84% | 54,230 psi | 85% | 3186 fps | 99.9% |
| ADI AR 2213 | <<locked>> | 88% | 56,579 psi | 89% | 3264 fps | 99.7% |
| ADI AR 2217 | <<locked>> | 96% | 55,405 psi | 87% | 3235 fps | 99.8% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 55,912 psi | 88% | 3353 fps | 98.2% |
| ADI AR 2225 | <<locked>> | 98% | 54,230 psi | 85% | 3255 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 84% | 54,418 psi | 85% | 3182 fps | 99.9% |
| Alliant Reloder-19 | <<locked>> | 86% | 57,435 psi | 90% | 3235 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 88% | 56,884 psi | 89% | 3255 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 88% | 54,839 psi | 86% | 3156 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 92% | 55,419 psi | 87% | 3235 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 84% | 55,477 psi | 87% | 3245 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 96% | 53,359 psi | 84% | 3255 fps | 97.4% |
| Alliant Reloder-50ᴾ | <<locked>> | 100% | 52,968 psi | 83% | 3232 fps | 96.8% |
| Baschieri & Pellagri 109 | <<locked>> | 90% | 57,232 psi | 90% | 3219 fps | 98.3% |
| Bofors RP15 | <<locked>> | 90% | 56,231 psi | 88% | 3245 fps | 100% |
| Bofors RP30 | <<locked>> | 94% | 55,114 psi | 86% | 3245 fps | 99.8% |
| Bofors RP5 | <<locked>> | 88% | 56,884 psi | 89% | 3255 fps | 100% |
| Hodgdon H1000 | <<locked>> | 94% | 56,884 psi | 89% | 3258 fps | 100% |
| Hodgdon H4831 | <<locked>> | 86% | 55,477 psi | 87% | 3189 fps | 99.3% |
| Hodgdon H4831 SC | <<locked>> | 86% | 54,476 psi | 85% | 3169 fps | 99.2% |
| Hodgdon Hybrid 100V | <<locked>> | 82% | 54,375 psi | 85% | 3091 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 92% | 54,476 psi | 85% | 3323 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,637 psi | 59% | 2080 fps | 100% |
| IMR 4350 | <<locked>> | 82% | 56,333 psi | 88% | 3163 fps | 100% |
| IMR 4831 | <<locked>> | 82% | 56,942 psi | 89% | 3159 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 86% | 55,883 psi | 88% | 3166 fps | 99.4% |
| IMR 7828 SSC | <<locked>> | 88% | 54,839 psi | 86% | 3241 fps | 99.6% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 53,098 psi | 83% | 3225 fps | 99.6% |
| Lovex S071 | <<locked>> | 92% | 54,563 psi | 86% | 3120 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 54,172 psi | 85% | 3251 fps | 100% |
| Norma MRP | <<locked>> | 86% | 57,087 psi | 89% | 3271 fps | 100% |
| Ramshot Grand | <<locked>> | 88% | 56,188 psi | 88% | 3264 fps | 99.8% |
| Ramshot Magnum | <<locked>> | 90% | 54,578 psi | 86% | 3186 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,522 psi | 60% | 2129 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 92% | 55,347 psi | 87% | 3307 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 94% | 54,650 psi | 86% | 3261 fps | 99.2% |
| Rottweil R 904 | <<locked>> | 84% | 54,650 psi | 86% | 3153 fps | 99.5% |
| Rottweil R 905 | <<locked>> | 86% | 57,188 psi | 90% | 3228 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 86% | 56,826 psi | 89% | 3222 fps | 100% |
| Somchem S361 | <<locked>> | 84% | 56,188 psi | 88% | 3143 fps | 99.4% |
| Somchem S365 | <<locked>> | 82% | 56,376 psi | 88% | 3153 fps | 100% |
| Somchem S385 | <<locked>> | 86% | 57,464 psi | 90% | 3189 fps | 100% |
| Vihtavuori N165 | <<locked>> | 90% | 57,624 psi | 90% | 3176 fps | 100% |
| Vihtavuori N170 | <<locked>> | 94% | 56,811 psi | 89% | 3192 fps | 96.6% |
| Vihtavuori N555 | <<locked>> | 86% | 56,478 psi | 89% | 3186 fps | 100% |
| Vihtavuori N560 | <<locked>> | 86% | 56,521 psi | 89% | 3278 fps | 99.5% |
| Vihtavuori N565 | <<locked>> | 92% | 57,435 psi | 90% | 3264 fps | 99.7% |
| Vihtavuori N568 | <<locked>> | 94% | 55,245 psi | 87% | 3268 fps | 98.9% |
| Vihtavuori N570 | <<locked>> | 96% | 56,594 psi | 89% | 3337 fps | 97.7% |
| Winchester StaBALL HD | <<locked>> | 88% | 55,071 psi | 86% | 3248 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 88% | 57,624 psi | 90% | 3189 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% | 42,801 psi | 67% | 2904 fps | 99.8% |
| Accurate High Country | <<locked>> | 80% | 47,326 psi | 74% | 3114 fps | 98.6% |
| Accurate MAGPRO | <<locked>> | 80% | 44,788 psi | 70% | 3045 fps | 96.9% |
| ADI AR 2209 | <<locked>> | 80% | 47,268 psi | 74% | 3058 fps | 99.2% |
| ADI AR 2213 | <<locked>> | 80% | 42,482 psi | 67% | 2989 fps | 97.4% |
| ADI AR 2217 | <<locked>> | 84% | 36,158 psi | 57% | 2828 fps | 95.7% |
| ADI AR 2218 | <<locked>> | 96% | 48,037 psi | 75% | 3189 fps | 96% |
| ADI AR 2225 | <<locked>> | 80% | 28,674 psi | 45% | 2644 fps | 95.1% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 47,587 psi | 75% | 3054 fps | 99.3% |
| Alliant Reloder-19 | <<locked>> | 80% | 47,137 psi | 74% | 3048 fps | 99.2% |
| Alliant Reloder-22 | <<locked>> | 80% | 43,149 psi | 68% | 2992 fps | 98.6% |
| Alliant Reloder-23 | <<locked>> | 80% | 41,785 psi | 65% | 2927 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 36,114 psi | 57% | 2854 fps | 99.5% |
| Alliant Reloder-26 | <<locked>> | 80% | 47,514 psi | 74% | 3107 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 92% | 45,672 psi | 72% | 3097 fps | 95.3% |
| Alliant Reloder-50 | <<locked>> | 98% | 48,892 psi | 77% | 3153 fps | 95.7% |
| Baschieri & Pellagri 109 | <<locked>> | 82% | 43,976 psi | 69% | 2959 fps | 95% |
| Bofors RP15 | <<locked>> | 80% | 40,016 psi | 63% | 2917 fps | 97.7% |
| Bofors RP30 | <<locked>> | 82% | 35,998 psi | 56% | 2835 fps | 95.7% |
| Bofors RP5 | <<locked>> | 80% | 43,149 psi | 68% | 2992 fps | 98.6% |
| Hodgdon H1000 | <<locked>> | 80% | 34,214 psi | 54% | 2776 fps | 95.5% |
| Hodgdon H4831 | <<locked>> | 80% | 44,947 psi | 70% | 2989 fps | 97.5% |
| Hodgdon H4831 SC | <<locked>> | 80% | 44,266 psi | 69% | 2972 fps | 97.3% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 50,850 psi | 80% | 3038 fps | 100% |
| Hodgdon Retumbo | 90.9 gr | 80% | 35,259 psi | 55% | 2890 fps | 97.1% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,224 psi | 44% | 1867 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 52,881 psi | 83% | 3104 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 53,359 psi | 84% | 3104 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 46,050 psi | 72% | 2982 fps | 97.9% |
| IMR 7828 SSC | <<locked>> | 80% | 41,191 psi | 65% | 2966 fps | 97.1% |
| IMR 8133 Enduron | <<locked>> | 90% | 37,376 psi | 59% | 2890 fps | 96.1% |
| Lovex S071 | <<locked>> | 80% | 36,709 psi | 58% | 2769 fps | 98.9% |
| Norma 217 | <<locked>> | 84% | 30,226 psi | 47% | 2707 fps | 95.2% |
| Norma MRP | <<locked>> | 80% | 45,890 psi | 72% | 3068 fps | 99.7% |
| Ramshot Grand | <<locked>> | 80% | 41,205 psi | 65% | 2976 fps | 97.5% |
| Ramshot Magnum | <<locked>> | 80% | 37,043 psi | 58% | 2835 fps | 97.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,834 psi | 45% | 1906 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 34,490 psi | 54% | 2858 fps | 98% |
| ReloadSwiss RS 80 | 105.4 gr | 86% | 39,929 psi | 63% | 2956 fps | 95.5% |
| Rottweil R 904 | <<locked>> | 80% | 47,964 psi | 75% | 3028 fps | 98.7% |
| Rottweil R 905 | <<locked>> | 80% | 46,630 psi | 73% | 3035 fps | 99.2% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 46,296 psi | 73% | 3031 fps | 99.2% |
| Somchem S361 | <<locked>> | 80% | 49,052 psi | 77% | 3015 fps | 98.4% |
| Somchem S365 | <<locked>> | 80% | 52,721 psi | 83% | 3097 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 47,050 psi | 74% | 3009 fps | 99.7% |
| Vihtavuori N165 | <<locked>> | 80% | 41,046 psi | 64% | 2871 fps | 98.6% |
| Vihtavuori N170 | <<locked>> | 92% | 52,895 psi | 83% | 3123 fps | 95.7% |
| Vihtavuori N555 | <<locked>> | 80% | 46,253 psi | 72% | 3012 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 45,556 psi | 71% | 3064 fps | 97.7% |
| Vihtavuori N565 | <<locked>> | 80% | 37,521 psi | 59% | 2851 fps | 95.4% |
| Vihtavuori N568 | <<locked>> | 86% | 41,060 psi | 64% | 2979 fps | 95.3% |
| Vihtavuori N570 | 108.4 gr | 92% | 48,660 psi | 76% | 3182 fps | 95.7% |
| Winchester StaBALL HD | <<locked>> | 80% | 40,059 psi | 63% | 2982 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 43,308 psi | 68% | 2930 fps | 98.6% |
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 54 powders for .30-378 Weath. Mag. loaded with the .308 | 166gr | Hammer Stone Hammer. ADI AR 2218 delivers the highest muzzle velocity at 3,353 fps; across all powders the maximum-charge window runs from 2,080 fps to 3,353 fps. ADI AR 2218 gives the best case fill at 100 %, and 54 of the 54 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 59–90 %, leaving at least 10 % headroom. The 166.0 gr projectile in 0.308" calls for a 1:12.5 twist; slower twists will usually not stabilise this weight. ADI AR 2218, Alliant Reloder-50, Hodgdon TrailBoss 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 80, Vihtavuori N570 rank at the top here: for .30-378 Weath. Mag. with the .308 | 166gr | Hammer Stone Hammer 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.