Load Specifications
Load data in caliber .30-378 Weath. Mag. with .308 | 170gr | Impala RNFP KO bullet and 49 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ADI AR 2218, Vihtavuori N570 and Hodgdon Retumbo.
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% | 55,550 psi | 87% | 3084 fps | 100% |
| Accurate 8700ᴾ | <<locked>> | 100% | 49,937 psi | 78% | 3087 fps | 96.3% |
| Accurate MAGPRO | <<locked>> | 84% | 57,508 psi | 90% | 3248 fps | 99.4% |
| ADI AR 2209 | <<locked>> | 82% | 55,230 psi | 87% | 3156 fps | 100% |
| ADI AR 2213 | <<locked>> | 86% | 57,696 psi | 90% | 3238 fps | 99.9% |
| ADI AR 2217 | <<locked>> | 94% | 56,898 psi | 89% | 3219 fps | 100% |
| ADI AR 2218 | <<locked>> | 98% | 57,595 psi | 90% | 3346 fps | 98.7% |
| ADI AR 2225 | <<locked>> | 96% | 56,492 psi | 89% | 3245 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 82% | 54,984 psi | 86% | 3150 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 84% | 54,882 psi | 86% | 3176 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 86% | 56,840 psi | 89% | 3136 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 90% | 57,363 psi | 90% | 3219 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 94% | 55,912 psi | 88% | 3261 fps | 98.1% |
| Alliant Reloder-50 | <<locked>> | 98% | 56,608 psi | 89% | 3261 fps | 97.8% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 57,696 psi | 90% | 3186 fps | 98.5% |
| Bofors RP15 | <<locked>> | 86% | 54,520 psi | 85% | 3169 fps | 100% |
| Bofors RP30 | <<locked>> | 92% | 57,537 psi | 90% | 3241 fps | 100% |
| Bofors RP5 | <<locked>> | 84% | 54,882 psi | 86% | 3176 fps | 100% |
| Hodgdon H1000 | <<locked>> | 90% | 54,418 psi | 85% | 3176 fps | 100% |
| Hodgdon H4831 | <<locked>> | 84% | 56,507 psi | 89% | 3159 fps | 99.5% |
| Hodgdon H4831 SC | <<locked>> | 84% | 55,535 psi | 87% | 3146 fps | 99.4% |
| Hodgdon Retumbo | <<locked>> | 90% | 56,550 psi | 89% | 3314 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 38,145 psi | 60% | 2060 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 84% | 56,681 psi | 89% | 3140 fps | 99.6% |
| IMR 7828 SSC | <<locked>> | 86% | 56,405 psi | 88% | 3225 fps | 99.8% |
| IMR 8133 Enduron | <<locked>> | 98% | 55,898 psi | 88% | 3232 fps | 99.9% |
| Lovex S071 | <<locked>> | 90% | 57,464 psi | 90% | 3114 fps | 100% |
| Norma 217 | <<locked>> | 98% | 57,348 psi | 90% | 3255 fps | 100% |
| Norma MRP | <<locked>> | 82% | 54,969 psi | 86% | 3192 fps | 100% |
| Ramshot Grand | <<locked>> | 84% | 53,925 psi | 85% | 3182 fps | 99.8% |
| Ramshot Magnum | <<locked>> | 88% | 56,637 psi | 89% | 3173 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 39,175 psi | 61% | 2110 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 90% | 57,522 psi | 90% | 3297 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 92% | 57,203 psi | 90% | 3268 fps | 99.6% |
| Rottweil R 904 | <<locked>> | 82% | 55,651 psi | 87% | 3123 fps | 99.7% |
| Rottweil R 905 | <<locked>> | 82% | 55,056 psi | 86% | 3146 fps | 100% |
| SNPE Vectan SP 13ᴾ | <<locked>> | 100% | 52,098 psi | 82% | 3104 fps | 96.4% |
| SNPE Vectan Tubal 8000 | <<locked>> | 82% | 54,679 psi | 86% | 3140 fps | 100% |
| Somchem S361 | <<locked>> | 82% | 57,261 psi | 90% | 3117 fps | 99.6% |
| Somchem S385 | <<locked>> | 82% | 55,564 psi | 87% | 3110 fps | 100% |
| Vihtavuori N165 | <<locked>> | 86% | 55,376 psi | 87% | 3097 fps | 100% |
| Vihtavuori N170 | <<locked>> | 90% | 54,984 psi | 86% | 3120 fps | 96.4% |
| Vihtavuori N555 | <<locked>> | 82% | 55,535 psi | 87% | 3120 fps | 100% |
| Vihtavuori N560 | <<locked>> | 82% | 54,201 psi | 85% | 3192 fps | 99.4% |
| Vihtavuori N565 | <<locked>> | 88% | 56,115 psi | 88% | 3196 fps | 99.7% |
| Vihtavuori N568 | <<locked>> | 92% | 57,406 psi | 90% | 3264 fps | 99.3% |
| Vihtavuori N570 | <<locked>> | 92% | 54,984 psi | 86% | 3268 fps | 97.6% |
| Winchester StaBALL HD | <<locked>> | 86% | 57,740 psi | 90% | 3241 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 84% | 54,998 psi | 86% | 3104 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% | 48,994 psi | 77% | 2976 fps | 100% |
| Accurate 8700 | <<locked>> | 98% | 46,528 psi | 73% | 3018 fps | 95.2% |
| Accurate MAGPRO | <<locked>> | 80% | 50,386 psi | 79% | 3117 fps | 98.5% |
| ADI AR 2209 | <<locked>> | 80% | 51,851 psi | 81% | 3097 fps | 99.8% |
| ADI AR 2213 | <<locked>> | 80% | 47,268 psi | 74% | 3048 fps | 98.7% |
| ADI AR 2217 | <<locked>> | 80% | 35,955 psi | 56% | 2779 fps | 96% |
| ADI AR 2218 | 110.1 gr | 92% | 46,644 psi | 73% | 3120 fps | 95.9% |
| ADI AR 2225 | <<locked>> | 80% | 33,605 psi | 53% | 2762 fps | 98.2% |
| Alliant Reloder-19 | <<locked>> | 80% | 51,721 psi | 81% | 3091 fps | 99.8% |
| Alliant Reloder-22 | <<locked>> | 80% | 48,385 psi | 76% | 3058 fps | 99.6% |
| Alliant Reloder-23 | <<locked>> | 80% | 47,108 psi | 74% | 2982 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 41,336 psi | 65% | 2933 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 88% | 45,194 psi | 71% | 3048 fps | 95.4% |
| Alliant Reloder-50 | <<locked>> | 92% | 45,876 psi | 72% | 3051 fps | 95.1% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 44,904 psi | 70% | 2943 fps | 95.7% |
| Bofors RP15 | <<locked>> | 80% | 45,136 psi | 71% | 2989 fps | 99.1% |
| Bofors RP30 | <<locked>> | 80% | 39,088 psi | 61% | 2874 fps | 97.2% |
| Bofors RP5 | <<locked>> | 80% | 48,385 psi | 76% | 3058 fps | 99.6% |
| Hodgdon H1000 | <<locked>> | 80% | 38,972 psi | 61% | 2861 fps | 97.7% |
| Hodgdon H4831 | <<locked>> | 80% | 49,719 psi | 78% | 3041 fps | 98.7% |
| Hodgdon H4831 SC | <<locked>> | 80% | 48,907 psi | 77% | 3025 fps | 98.5% |
| Hodgdon Retumbo | 90.4 gr | 80% | 40,422 psi | 63% | 2989 fps | 99.1% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,732 psi | 45% | 1847 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 50,169 psi | 79% | 3022 fps | 98.9% |
| IMR 7828 SSC | <<locked>> | 80% | 46,166 psi | 72% | 3031 fps | 98.6% |
| IMR 8133 Enduron | <<locked>> | 84% | 35,694 psi | 56% | 2805 fps | 95.9% |
| Lovex S071 | <<locked>> | 80% | 42,656 psi | 67% | 2854 fps | 99.9% |
| Norma 217 | <<locked>> | 80% | 31,792 psi | 50% | 2717 fps | 96.6% |
| Norma MRP | <<locked>> | 80% | 51,488 psi | 81% | 3130 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 46,702 psi | 73% | 3051 fps | 99% |
| Ramshot Magnum | <<locked>> | 80% | 42,656 psi | 67% | 2923 fps | 99.4% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,573 psi | 46% | 1890 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 40,089 psi | 63% | 2966 fps | 99.7% |
| ReloadSwiss RS 80 | <<locked>> | 82% | 40,161 psi | 63% | 2923 fps | 96% |
| Rottweil R 904 | <<locked>> | 80% | 52,315 psi | 82% | 3068 fps | 99.4% |
| Rottweil R 905 | <<locked>> | 80% | 51,706 psi | 81% | 3084 fps | 99.8% |
| SNPE Vectan SP 13 | <<locked>> | 98% | 48,849 psi | 77% | 3041 fps | 95.5% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 51,358 psi | 80% | 3081 fps | 99.8% |
| Somchem S361 | <<locked>> | 80% | 53,693 psi | 84% | 3054 fps | 99.2% |
| Somchem S385 | <<locked>> | 80% | 52,315 psi | 82% | 3058 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 45,963 psi | 72% | 2930 fps | 99.6% |
| Vihtavuori N170 | <<locked>> | 88% | 51,663 psi | 81% | 3061 fps | 95.6% |
| Vihtavuori N555 | <<locked>> | 80% | 52,243 psi | 82% | 3068 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 50,792 psi | 80% | 3127 fps | 99% |
| Vihtavuori N565 | <<locked>> | 80% | 43,323 psi | 68% | 2949 fps | 97.7% |
| Vihtavuori N568 | <<locked>> | 82% | 40,915 psi | 64% | 2933 fps | 95.7% |
| Vihtavuori N570 | 103.2 gr | 88% | 47,950 psi | 75% | 3130 fps | 95.8% |
| Winchester StaBALL HD | <<locked>> | 80% | 46,586 psi | 73% | 3064 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 48,225 psi | 76% | 2982 fps | 99.5% |
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 56 powders for .30-378 Weath. Mag. loaded with the .308 | 170gr | Impala RNFP KO. ADI AR 2218 delivers the highest muzzle velocity at 3,346 fps; across all powders the maximum-charge window runs from 2,060 fps to 3,346 fps. Accurate 8700 gives the best case fill at 100 %, and 56 of the 56 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 170.0 gr projectile in 0.308" calls for a 1:12.5 twist; slower twists will usually not stabilise this weight. Accurate 8700, Hodgdon TrailBoss, Hodgdon US 869 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. ADI AR 2218, Vihtavuori N570, Hodgdon Retumbo rank at the top here: for .30-378 Weath. Mag. with the .308 | 170gr | Impala RNFP KO they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Hodgdon US 869, IMR 7977 Enduron, Lovex D100 burn incompletely and react more sensitively to barrel length and temperature. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.