Load Specifications
Load data in caliber .30-378 Weath. Mag. with .308 | 155gr | Berger BT Target bullet and 57 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Vihtavuori N570, Hodgdon Retumbo and ReloadSwiss RS 76.
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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You can find more information in our FAQ: How can I use the Personalized Load Calculator?
Max Load - Barrel Length: 26"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 88% | 55,811 psi | 87% | 3225 fps | 100% |
| Accurate High Country | <<locked>> | 86% | 57,551 psi | 90% | 3389 fps | 99.6% |
| Accurate MAGPRO | <<locked>> | 86% | 54,752 psi | 86% | 3327 fps | 98.5% |
| ADI AR 2209 | <<locked>> | 86% | 56,869 psi | 89% | 3317 fps | 99.9% |
| ADI AR 2213 | <<locked>> | 88% | 55,274 psi | 87% | 3327 fps | 99.3% |
| ADI AR 2217 | <<locked>> | 96% | 54,128 psi | 85% | 3297 fps | 99.5% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 54,795 psi | 86% | 3406 fps | 97.2% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 56,739 psi | 89% | 3383 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 82% | 56,985 psi | 89% | 3310 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 86% | 56,550 psi | 89% | 3307 fps | 99.9% |
| Alliant Reloder-22 | <<locked>> | 88% | 55,753 psi | 87% | 3323 fps | 99.9% |
| Alliant Reloder-23 | <<locked>> | 90% | 57,566 psi | 90% | 3287 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 92% | 54,041 psi | 85% | 3301 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 84% | 54,404 psi | 85% | 3317 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 98% | 56,333 psi | 88% | 3386 fps | 97.4% |
| Baschieri & Pellagri 109 | <<locked>> | 90% | 56,115 psi | 88% | 3281 fps | 97.5% |
| Bofors RP15 | <<locked>> | 90% | 55,114 psi | 86% | 3310 fps | 99.8% |
| Bofors RP30 | <<locked>> | 94% | 54,012 psi | 85% | 3310 fps | 99.5% |
| Bofors RP5 | <<locked>> | 88% | 55,753 psi | 87% | 3323 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 94% | 55,521 psi | 87% | 3320 fps | 99.8% |
| Hodgdon H4831 | <<locked>> | 86% | 54,549 psi | 85% | 3255 fps | 98.8% |
| Hodgdon H4831 SC | <<locked>> | 88% | 57,203 psi | 90% | 3301 fps | 99.1% |
| Hodgdon Hybrid 100V | <<locked>> | 84% | 57,188 psi | 90% | 3225 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 94% | 57,087 psi | 89% | 3458 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,594 psi | 59% | 2149 fps | 100% |
| IMR 4350 | <<locked>> | 82% | 55,506 psi | 87% | 3232 fps | 100% |
| IMR 4831 | <<locked>> | 82% | 56,188 psi | 88% | 3238 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 86% | 54,955 psi | 86% | 3232 fps | 99% |
| IMR 7828 SSC | <<locked>> | 90% | 57,638 psi | 90% | 3376 fps | 99.6% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 52,083 psi | 82% | 3287 fps | 99.2% |
| Lovex S070 | <<locked>> | 82% | 57,696 psi | 90% | 3268 fps | 100% |
| Lovex S071 | <<locked>> | 94% | 57,508 psi | 90% | 3248 fps | 100% |
| Norma 204 | <<locked>> | 82% | 56,869 psi | 89% | 3297 fps | 99.8% |
| Norma 217ᴾ | <<locked>> | 100% | 53,040 psi | 83% | 3314 fps | 100% |
| Norma MRP | <<locked>> | 86% | 55,869 psi | 88% | 3340 fps | 100% |
| Norma URP | <<locked>> | 82% | 57,740 psi | 90% | 3287 fps | 100% |
| Ramshot Grand | <<locked>> | 88% | 54,708 psi | 86% | 3327 fps | 99.5% |
| Ramshot Hunter | <<locked>> | 82% | 56,869 psi | 89% | 3294 fps | 100% |
| Ramshot Magnum | <<locked>> | 92% | 57,609 psi | 90% | 3317 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,479 psi | 60% | 2195 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 92% | 53,969 psi | 85% | 3373 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 96% | 57,653 psi | 90% | 3399 fps | 99.2% |
| Rottweil R 904 | <<locked>> | 86% | 57,479 psi | 90% | 3284 fps | 99.5% |
| Rottweil R 905 | <<locked>> | 86% | 56,173 psi | 88% | 3294 fps | 99.9% |
| Shooters World SW4350 | <<locked>> | 82% | 57,696 psi | 90% | 3268 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 86% | 55,782 psi | 87% | 3291 fps | 99.8% |
| Somchem S361 | <<locked>> | 84% | 55,274 psi | 87% | 3205 fps | 98.9% |
| Somchem S365 | <<locked>> | 82% | 55,463 psi | 87% | 3232 fps | 100% |
| Somchem S385 | <<locked>> | 86% | 56,594 psi | 89% | 3261 fps | 100% |
| Vihtavuori N165 | <<locked>> | 90% | 56,579 psi | 89% | 3245 fps | 100% |
| Vihtavuori N555 | <<locked>> | 86% | 55,811 psi | 87% | 3261 fps | 100% |
| Vihtavuori N560 | <<locked>> | 86% | 55,317 psi | 87% | 3340 fps | 99% |
| Vihtavuori N565 | <<locked>> | 92% | 56,449 psi | 88% | 3330 fps | 99.3% |
| Vihtavuori N568 | <<locked>> | 94% | 53,954 psi | 85% | 3327 fps | 98.2% |
| Vihtavuori N570 | <<locked>> | 96% | 55,143 psi | 86% | 3392 fps | 96.8% |
| Winchester StaBALL HD | <<locked>> | 88% | 53,577 psi | 84% | 3317 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 88% | 56,492 psi | 89% | 3255 fps | 99.9% |
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% | 42,366 psi | 66% | 2972 fps | 99.5% |
| Accurate High Country | <<locked>> | 80% | 46,557 psi | 73% | 3176 fps | 97.9% |
| Accurate MAGPRO | <<locked>> | 80% | 44,048 psi | 69% | 3104 fps | 96% |
| ADI AR 2209 | <<locked>> | 80% | 46,354 psi | 73% | 3120 fps | 98.7% |
| ADI AR 2213 | <<locked>> | 80% | 41,684 psi | 65% | 3045 fps | 96.5% |
| ADI AR 2217 | <<locked>> | 86% | 38,174 psi | 60% | 2949 fps | 95.7% |
| ADI AR 2218 | <<locked>> | 98% | 50,705 psi | 79% | 3320 fps | 96% |
| ADI AR 2225 | <<locked>> | 82% | 30,458 psi | 48% | 2769 fps | 95.3% |
| Alliant Reloder-16 | <<locked>> | 80% | 53,374 psi | 84% | 3251 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 46,311 psi | 73% | 3110 fps | 98.7% |
| Alliant Reloder-22 | <<locked>> | 80% | 42,409 psi | 66% | 3054 fps | 97.9% |
| Alliant Reloder-23 | <<locked>> | 80% | 41,191 psi | 65% | 2999 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 35,505 psi | 56% | 2913 fps | 98.9% |
| Alliant Reloder-26 | <<locked>> | 80% | 46,717 psi | 73% | 3179 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 94% | 48,370 psi | 76% | 3232 fps | 95.4% |
| Baschieri & Pellagri 109 | <<locked>> | 86% | 49,240 psi | 77% | 3150 fps | 95.9% |
| Bofors RP15 | <<locked>> | 80% | 39,537 psi | 62% | 2982 fps | 97% |
| Bofors RP30 | <<locked>> | 84% | 38,189 psi | 60% | 2969 fps | 95.8% |
| Bofors RP5 | <<locked>> | 80% | 42,409 psi | 66% | 3054 fps | 97.9% |
| Hodgdon H1000 | <<locked>> | 82% | 36,201 psi | 57% | 2900 fps | 95.5% |
| Hodgdon H4831 | <<locked>> | 80% | 44,295 psi | 69% | 3051 fps | 96.6% |
| Hodgdon H4831 SC | <<locked>> | 80% | 43,497 psi | 68% | 3031 fps | 96.4% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 50,154 psi | 79% | 3110 fps | 100% |
| Hodgdon Retumbo | 91.6 gr | 80% | 34,679 psi | 54% | 2946 fps | 96% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,181 psi | 44% | 1926 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 51,982 psi | 81% | 3169 fps | 99.8% |
| IMR 4831 | <<locked>> | 80% | 52,547 psi | 82% | 3179 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 45,310 psi | 71% | 3045 fps | 97.1% |
| IMR 7828 SSC | <<locked>> | 80% | 40,364 psi | 63% | 3022 fps | 96.1% |
| IMR 8133 Enduron | <<locked>> | 90% | 36,724 psi | 58% | 2943 fps | 95% |
| Lovex S070 | <<locked>> | 80% | 54,215 psi | 85% | 3209 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 36,535 psi | 57% | 2838 fps | 98.4% |
| Norma 204 | <<locked>> | 80% | 53,011 psi | 83% | 3228 fps | 99.5% |
| Norma 217 | <<locked>> | 86% | 32,184 psi | 50% | 2835 fps | 95.4% |
| Norma MRP | <<locked>> | 80% | 45,078 psi | 71% | 3136 fps | 99.4% |
| Norma URP | <<locked>> | 80% | 54,128 psi | 85% | 3225 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 40,437 psi | 63% | 3035 fps | 96.6% |
| Ramshot Hunter | <<locked>> | 80% | 53,084 psi | 83% | 3228 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 36,448 psi | 57% | 2894 fps | 97.1% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,906 psi | 45% | 1972 fps | 100% |
| ReloadSwiss RS 76 | 98.1 gr | 80% | 34,113 psi | 53% | 2917 fps | 97.1% |
| ReloadSwiss RS 80 | <<locked>> | 88% | 42,438 psi | 67% | 3094 fps | 95.8% |
| Rottweil R 904 | <<locked>> | 80% | 47,311 psi | 74% | 3094 fps | 98% |
| Rottweil R 905 | <<locked>> | 80% | 45,876 psi | 72% | 3100 fps | 98.7% |
| Shooters World SW4350 | <<locked>> | 80% | 54,215 psi | 85% | 3209 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 45,527 psi | 71% | 3094 fps | 98.6% |
| Somchem S361 | <<locked>> | 80% | 48,370 psi | 76% | 3077 fps | 97.7% |
| Somchem S365 | <<locked>> | 80% | 51,735 psi | 81% | 3173 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 46,383 psi | 73% | 3074 fps | 99.3% |
| Vihtavuori N165 | <<locked>> | 80% | 40,451 psi | 63% | 2930 fps | 97.9% |
| Vihtavuori N555 | <<locked>> | 80% | 45,788 psi | 72% | 3087 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 44,788 psi | 70% | 3127 fps | 96.9% |
| Vihtavuori N565 | <<locked>> | 82% | 39,958 psi | 63% | 2989 fps | 95.6% |
| Vihtavuori N568 | <<locked>> | 88% | 43,482 psi | 68% | 3110 fps | 95.4% |
| Vihtavuori N570 | 111.7 gr | 94% | 51,198 psi | 80% | 3314 fps | 95.7% |
| Winchester StaBALL HD | <<locked>> | 80% | 39,175 psi | 61% | 3051 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 42,728 psi | 67% | 2992 fps | 98% |
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 65 powders for .30-378 Weath. Mag. loaded with the .308 | 155gr | Berger BT Target. Hodgdon Retumbo delivers the highest muzzle velocity at 3,458 fps; across all powders the maximum-charge window runs from 2,149 fps to 3,458 fps. Accurate 8700 gives the best case fill at 100 %, and 65 of the 65 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 155.0 gr projectile in 0.308" calls for a 1:13.0 twist; slower twists will usually not stabilise this weight. Accurate 8700, ADI AR 2218, ADI AR 2225 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. Vihtavuori N570, Hodgdon Retumbo, ReloadSwiss RS 76 rank at the top here: for .30-378 Weath. Mag. with the .308 | 155gr | Berger BT Target they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Accurate 8700, 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.