Load Specifications
Load data in caliber .30-378 Weath. Mag. with .308 | 170gr | Geco PLUS bullet and 50 powders. The key underlying parameters are shown in the table above.
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>> | 86% | 56,521 psi | 89% | 3114 fps | 100% |
| Accurate High Country | <<locked>> | 82% | 54,607 psi | 86% | 3219 fps | 99.7% |
| Accurate MAGPRO | <<locked>> | 84% | 55,593 psi | 87% | 3225 fps | 99.3% |
| ADI AR 2209 | <<locked>> | 84% | 57,508 psi | 90% | 3209 fps | 100% |
| ADI AR 2213 | <<locked>> | 86% | 56,202 psi | 88% | 3225 fps | 99.8% |
| ADI AR 2217 | <<locked>> | 94% | 55,230 psi | 87% | 3199 fps | 99.9% |
| ADI AR 2218 | <<locked>> | 98% | 55,927 psi | 88% | 3323 fps | 98.5% |
| ADI AR 2225 | <<locked>> | 96% | 54,607 psi | 86% | 3222 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 84% | 57,058 psi | 89% | 3196 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 86% | 56,739 psi | 89% | 3219 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 86% | 54,868 psi | 86% | 3117 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 90% | 55,434 psi | 87% | 3196 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 82% | 55,593 psi | 87% | 3205 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 94% | 53,766 psi | 84% | 3225 fps | 97.8% |
| Alliant Reloder-50 | <<locked>> | 98% | 53,838 psi | 84% | 3215 fps | 97.3% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 56,536 psi | 89% | 3176 fps | 98.4% |
| Bofors RP15 | <<locked>> | 88% | 56,101 psi | 88% | 3205 fps | 100% |
| Bofors RP30 | <<locked>> | 92% | 55,332 psi | 87% | 3212 fps | 99.9% |
| Bofors RP5 | <<locked>> | 86% | 56,739 psi | 89% | 3219 fps | 100% |
| Hodgdon H1000 | <<locked>> | 92% | 56,869 psi | 89% | 3225 fps | 100% |
| Hodgdon H4831 | <<locked>> | 84% | 55,056 psi | 86% | 3150 fps | 99.4% |
| Hodgdon H4831 SC | <<locked>> | 84% | 53,925 psi | 85% | 3130 fps | 99.3% |
| Hodgdon Hybrid 100V | <<locked>> | 82% | 57,653 psi | 90% | 3104 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 90% | 54,853 psi | 86% | 3291 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,840 psi | 59% | 2067 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 84% | 55,317 psi | 87% | 3127 fps | 99.5% |
| IMR 7828 SSC | <<locked>> | 86% | 54,665 psi | 86% | 3202 fps | 99.7% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 57,450 psi | 90% | 3261 fps | 100% |
| Lovex S071 | <<locked>> | 90% | 54,911 psi | 86% | 3091 fps | 100% |
| Norma 217 | <<locked>> | 98% | 55,027 psi | 86% | 3225 fps | 100% |
| Norma MRP | <<locked>> | 84% | 56,884 psi | 89% | 3232 fps | 100% |
| Ramshot Grand | <<locked>> | 86% | 55,941 psi | 88% | 3225 fps | 99.9% |
| Ramshot Magnum | <<locked>> | 88% | 54,491 psi | 85% | 3150 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,899 psi | 61% | 2116 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 90% | 55,680 psi | 87% | 3271 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 92% | 54,984 psi | 86% | 3235 fps | 99.4% |
| Rottweil R 904 | <<locked>> | 84% | 57,740 psi | 90% | 3173 fps | 99.9% |
| Rottweil R 905 | <<locked>> | 84% | 56,811 psi | 89% | 3186 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 84% | 56,420 psi | 88% | 3182 fps | 100% |
| Somchem S361 | <<locked>> | 82% | 55,419 psi | 87% | 3100 fps | 99.5% |
| Somchem S385 | <<locked>> | 84% | 57,116 psi | 90% | 3150 fps | 100% |
| Vihtavuori N165 | <<locked>> | 88% | 57,261 psi | 90% | 3140 fps | 100% |
| Vihtavuori N170 | <<locked>> | 92% | 56,594 psi | 89% | 3163 fps | 96.9% |
| Vihtavuori N555 | <<locked>> | 84% | 56,695 psi | 89% | 3150 fps | 100% |
| Vihtavuori N560 | <<locked>> | 84% | 56,202 psi | 88% | 3235 fps | 99.6% |
| Vihtavuori N565 | <<locked>> | 90% | 57,450 psi | 90% | 3232 fps | 99.8% |
| Vihtavuori N568 | <<locked>> | 92% | 55,419 psi | 87% | 3238 fps | 99.1% |
| Vihtavuori N570 | <<locked>> | 94% | 56,768 psi | 89% | 3307 fps | 98% |
| Winchester StaBALL HD | <<locked>> | 86% | 55,448 psi | 87% | 3212 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 86% | 57,145 psi | 90% | 3150 fps | 100% |
Start Load - Barrel Length: 26"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 80% | 46,195 psi | 72% | 2940 fps | 100% |
| Accurate High Country | <<locked>> | 80% | 50,908 psi | 80% | 3150 fps | 99.4% |
| Accurate MAGPRO | <<locked>> | 80% | 48,196 psi | 76% | 3084 fps | 98.1% |
| ADI AR 2209 | <<locked>> | 80% | 50,256 psi | 79% | 3081 fps | 99.7% |
| ADI AR 2213 | <<locked>> | 80% | 45,513 psi | 71% | 3022 fps | 98.5% |
| ADI AR 2217 | <<locked>> | 80% | 33,939 psi | 53% | 2736 fps | 95.1% |
| ADI AR 2218 | <<locked>> | 92% | 44,686 psi | 70% | 3084 fps | 95.3% |
| ADI AR 2225 | <<locked>> | 80% | 31,299 psi | 49% | 2700 fps | 97.2% |
| Alliant Reloder-19 | <<locked>> | 80% | 50,096 psi | 79% | 3071 fps | 99.7% |
| Alliant Reloder-22 | <<locked>> | 80% | 46,282 psi | 73% | 3025 fps | 99.4% |
| Alliant Reloder-23 | <<locked>> | 80% | 45,034 psi | 71% | 2953 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 39,218 psi | 61% | 2894 fps | 99.9% |
| Alliant Reloder-26 | <<locked>> | 80% | 51,576 psi | 81% | 3143 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 90% | 46,238 psi | 72% | 3074 fps | 95.8% |
| Alliant Reloder-50 | <<locked>> | 94% | 46,311 psi | 73% | 3064 fps | 95.2% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 43,497 psi | 68% | 2920 fps | 95.3% |
| Bofors RP15 | <<locked>> | 80% | 43,091 psi | 68% | 2956 fps | 98.7% |
| Bofors RP30 | <<locked>> | 80% | 36,651 psi | 57% | 2818 fps | 96.3% |
| Bofors RP5 | <<locked>> | 80% | 46,282 psi | 73% | 3025 fps | 99.4% |
| Hodgdon H1000 | <<locked>> | 80% | 36,927 psi | 58% | 2822 fps | 97.1% |
| Hodgdon H4831 | <<locked>> | 80% | 47,993 psi | 75% | 3018 fps | 98.4% |
| Hodgdon H4831 SC | <<locked>> | 80% | 47,152 psi | 74% | 3002 fps | 98.3% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 54,099 psi | 85% | 3051 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 80% | 38,290 psi | 60% | 2943 fps | 98.6% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,384 psi | 44% | 1854 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 48,689 psi | 76% | 3005 fps | 98.7% |
| IMR 7828 SSC | <<locked>> | 80% | 44,309 psi | 69% | 3002 fps | 98.2% |
| IMR 8133 Enduron | <<locked>> | 86% | 35,534 psi | 56% | 2805 fps | 95.7% |
| Lovex S071 | <<locked>> | 80% | 39,726 psi | 62% | 2805 fps | 99.6% |
| Norma 217 | <<locked>> | 82% | 31,183 psi | 49% | 2700 fps | 96.1% |
| Norma MRP | <<locked>> | 80% | 49,385 psi | 77% | 3104 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 44,744 psi | 70% | 3018 fps | 98.6% |
| Ramshot Magnum | <<locked>> | 80% | 40,364 psi | 63% | 2884 fps | 99% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,167 psi | 46% | 1896 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 37,797 psi | 59% | 2917 fps | 99.3% |
| ReloadSwiss RS 80 | <<locked>> | 82% | 37,521 psi | 59% | 2864 fps | 95% |
| Rottweil R 904 | <<locked>> | 80% | 50,792 psi | 80% | 3051 fps | 99.3% |
| Rottweil R 905 | <<locked>> | 80% | 49,806 psi | 78% | 3064 fps | 99.7% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 49,458 psi | 78% | 3058 fps | 99.7% |
| Somchem S361 | <<locked>> | 80% | 51,924 psi | 81% | 3038 fps | 99.1% |
| Somchem S385 | <<locked>> | 80% | 50,169 psi | 79% | 3031 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 43,961 psi | 69% | 2900 fps | 99.3% |
| Vihtavuori N170 | <<locked>> | 88% | 49,429 psi | 77% | 3028 fps | 95.1% |
| Vihtavuori N555 | <<locked>> | 80% | 49,806 psi | 78% | 3038 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 48,892 psi | 77% | 3100 fps | 98.7% |
| Vihtavuori N565 | <<locked>> | 80% | 40,857 psi | 64% | 2900 fps | 97% |
| Vihtavuori N568 | <<locked>> | 84% | 41,510 psi | 65% | 2956 fps | 95.9% |
| Vihtavuori N570 | <<locked>> | 88% | 45,716 psi | 72% | 3087 fps | 95.2% |
| Winchester StaBALL HD | <<locked>> | 80% | 44,179 psi | 69% | 3022 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 46,383 psi | 73% | 2959 fps | 99.3% |
ᴾ possible press load - work up slowly to this load while watching for signs of excessive pressure.
This overview compares 59 powders for .30-378 Weath. Mag. loaded with the .308 | 170gr | Geco PLUS. ADI AR 2218 delivers the highest muzzle velocity at 3,323 fps; across all powders the maximum-charge window runs from 2,067 fps to 3,323 fps. Accurate 8700 gives the best case fill at 100 %, and 59 of the 59 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 170.0 gr projectile in 0.308" calls for a 1:15.5 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. As outliers, Hodgdon US 869, Lovex D100, Ramshot LRT 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.