Load Specifications
Load data in caliber .30-378 Weath. Mag. with .308 | 185gr | Lapua Mega bullet and 50 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ADI AR 2218, Hodgdon Retumbo 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% | 55,883 psi | 88% | 2995 fps | 100% |
| Accurate 8700ᴾ | <<locked>> | 100% | 51,605 psi | 81% | 3031 fps | 97.7% |
| Accurate MAGPRO | <<locked>> | 82% | 54,926 psi | 86% | 3107 fps | 99.6% |
| ADI AR 2209 | <<locked>> | 82% | 56,666 psi | 89% | 3084 fps | 100% |
| ADI AR 2213 | <<locked>> | 84% | 55,622 psi | 87% | 3104 fps | 100% |
| ADI AR 2217 | <<locked>> | 92% | 55,143 psi | 86% | 3091 fps | 100% |
| ADI AR 2218 | <<locked>> | 96% | 55,651 psi | 87% | 3219 fps | 99.1% |
| ADI AR 2225 | <<locked>> | 94% | 54,795 psi | 86% | 3110 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 82% | 56,840 psi | 89% | 3077 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 82% | 56,275 psi | 88% | 3071 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 84% | 56,231 psi | 88% | 3097 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 84% | 54,534 psi | 85% | 2999 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 88% | 55,376 psi | 87% | 3081 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 92% | 53,722 psi | 84% | 3123 fps | 98.5% |
| Alliant Reloder-50 | <<locked>> | 96% | 53,853 psi | 84% | 3114 fps | 98.1% |
| Baschieri & Pellagri 109 | <<locked>> | 86% | 55,753 psi | 87% | 3064 fps | 98.9% |
| Bofors RP15 | <<locked>> | 86% | 55,608 psi | 87% | 3087 fps | 100% |
| Bofors RP30 | <<locked>> | 90% | 55,172 psi | 86% | 3104 fps | 100% |
| Bofors RP5 | <<locked>> | 84% | 56,231 psi | 88% | 3097 fps | 100% |
| Hodgdon H1000 | <<locked>> | 90% | 56,405 psi | 88% | 3104 fps | 100% |
| Hodgdon H4831 | <<locked>> | 82% | 54,114 psi | 85% | 3028 fps | 99.7% |
| Hodgdon H4831 SC | <<locked>> | 84% | 57,014 psi | 89% | 3074 fps | 99.9% |
| Hodgdon Retumbo | <<locked>> | 88% | 54,998 psi | 86% | 3176 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 38,087 psi | 60% | 1995 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 82% | 54,375 psi | 85% | 3005 fps | 99.8% |
| IMR 7828 SSC | <<locked>> | 84% | 54,186 psi | 85% | 3087 fps | 99.9% |
| IMR 7977 Enduron | <<locked>> | 90% | 56,666 psi | 89% | 3018 fps | 96.3% |
| IMR 8133 Enduron | <<locked>> | 98% | 57,653 psi | 90% | 3156 fps | 100% |
| Lovex S071 | <<locked>> | 88% | 54,433 psi | 85% | 2972 fps | 100% |
| Norma 217 | <<locked>> | 96% | 55,259 psi | 87% | 3117 fps | 100% |
| Norma MRP | <<locked>> | 82% | 56,304 psi | 88% | 3110 fps | 100% |
| Ramshot Grand | <<locked>> | 84% | 55,666 psi | 87% | 3110 fps | 100% |
| Ramshot Magnum | <<locked>> | 86% | 54,085 psi | 85% | 3035 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 39,059 psi | 61% | 2037 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 88% | 55,637 psi | 87% | 3156 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 90% | 54,824 psi | 86% | 3123 fps | 99.7% |
| Rottweil R 904 | <<locked>> | 82% | 56,927 psi | 89% | 3051 fps | 100% |
| Rottweil R 905 | <<locked>> | 82% | 56,217 psi | 88% | 3064 fps | 100% |
| SNPE Vectan SP 13ᴾ | <<locked>> | 100% | 53,476 psi | 84% | 3041 fps | 97.7% |
| SNPE Vectan Tubal 8000 | <<locked>> | 82% | 55,854 psi | 88% | 3061 fps | 100% |
| Somchem S385 | <<locked>> | 82% | 56,376 psi | 88% | 3028 fps | 100% |
| Vihtavuori N165 | <<locked>> | 86% | 56,565 psi | 89% | 3018 fps | 100% |
| Vihtavuori N170 | <<locked>> | 90% | 55,999 psi | 88% | 3051 fps | 97.6% |
| Vihtavuori N555 | <<locked>> | 82% | 56,260 psi | 88% | 3028 fps | 100% |
| Vihtavuori N560 | <<locked>> | 82% | 55,593 psi | 87% | 3114 fps | 99.9% |
| Vihtavuori N565 | <<locked>> | 88% | 57,174 psi | 90% | 3117 fps | 100% |
| Vihtavuori N568 | <<locked>> | 90% | 55,274 psi | 87% | 3130 fps | 99.5% |
| Vihtavuori N570 | <<locked>> | 92% | 56,753 psi | 89% | 3199 fps | 98.7% |
| Winchester StaBALL HD | <<locked>> | 84% | 55,622 psi | 87% | 3094 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 84% | 56,202 psi | 88% | 3028 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% | 48,892 psi | 77% | 2881 fps | 100% |
| Accurate 8700 | <<locked>> | 96% | 44,454 psi | 70% | 2890 fps | 95.7% |
| Accurate MAGPRO | <<locked>> | 80% | 51,271 psi | 80% | 3041 fps | 99.2% |
| ADI AR 2209 | <<locked>> | 80% | 52,997 psi | 83% | 3022 fps | 100% |
| ADI AR 2213 | <<locked>> | 80% | 48,312 psi | 76% | 2976 fps | 99.4% |
| ADI AR 2217 | <<locked>> | 80% | 36,129 psi | 57% | 2707 fps | 97.1% |
| ADI AR 2218 | 107.8 gr | 88% | 41,350 psi | 65% | 2910 fps | 95.1% |
| ADI AR 2225 | <<locked>> | 80% | 33,460 psi | 52% | 2677 fps | 98.9% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 53,214 psi | 83% | 3022 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 52,721 psi | 83% | 3012 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 80% | 49,066 psi | 77% | 2972 fps | 99.9% |
| Alliant Reloder-23 | <<locked>> | 80% | 47,805 psi | 75% | 2894 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 41,989 psi | 66% | 2844 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 86% | 42,873 psi | 67% | 2904 fps | 95.7% |
| Alliant Reloder-50 | <<locked>> | 90% | 43,033 psi | 67% | 2897 fps | 95.1% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 45,803 psi | 72% | 2877 fps | 97% |
| Bofors RP15 | <<locked>> | 80% | 45,701 psi | 72% | 2907 fps | 99.6% |
| Bofors RP30 | <<locked>> | 80% | 39,204 psi | 61% | 2785 fps | 98% |
| Bofors RP5 | <<locked>> | 80% | 49,066 psi | 77% | 2972 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 80% | 39,378 psi | 62% | 2785 fps | 98.6% |
| Hodgdon H4831 | <<locked>> | 80% | 50,604 psi | 79% | 2966 fps | 99.4% |
| Hodgdon H4831 SC | <<locked>> | 80% | 49,719 psi | 78% | 2949 fps | 99.3% |
| Hodgdon Retumbo | 92.5 gr | 80% | 41,104 psi | 64% | 2910 fps | 99.7% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,572 psi | 45% | 1785 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 51,010 psi | 80% | 2949 fps | 99.5% |
| IMR 7828 SSC | <<locked>> | 80% | 47,152 psi | 74% | 2959 fps | 99.3% |
| IMR 7977 Enduron | <<locked>> | 88% | 53,084 psi | 83% | 2956 fps | 95.4% |
| IMR 8133 Enduron | <<locked>> | 82% | 33,373 psi | 52% | 2654 fps | 95.8% |
| Lovex S071 | <<locked>> | 80% | 42,192 psi | 66% | 2756 fps | 100% |
| Norma 217 | <<locked>> | 80% | 31,517 psi | 49% | 2618 fps | 97.3% |
| Norma MRP | <<locked>> | 80% | 52,489 psi | 82% | 3048 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 47,906 psi | 75% | 2976 fps | 99.6% |
| Ramshot Magnum | <<locked>> | 80% | 43,221 psi | 68% | 2841 fps | 99.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,385 psi | 46% | 1827 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 40,756 psi | 64% | 2884 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 80% | 37,536 psi | 59% | 2772 fps | 96% |
| Rottweil R 904 | <<locked>> | 80% | 53,316 psi | 84% | 2992 fps | 99.9% |
| Rottweil R 905 | <<locked>> | 80% | 52,562 psi | 82% | 3005 fps | 100% |
| SNPE Vectan SP 13 | <<locked>> | 96% | 46,543 psi | 73% | 2913 fps | 96% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 52,214 psi | 82% | 3002 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 52,837 psi | 83% | 2972 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 46,441 psi | 73% | 2851 fps | 99.9% |
| Vihtavuori N170 | <<locked>> | 84% | 45,745 psi | 72% | 2861 fps | 95.1% |
| Vihtavuori N555 | <<locked>> | 80% | 52,663 psi | 83% | 2976 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 51,866 psi | 81% | 3051 fps | 99.6% |
| Vihtavuori N565 | <<locked>> | 80% | 43,497 psi | 68% | 2864 fps | 98.5% |
| Vihtavuori N568 | <<locked>> | 80% | 38,566 psi | 60% | 2789 fps | 95.8% |
| Vihtavuori N570 | 100.8 gr | 84% | 42,511 psi | 67% | 2913 fps | 95.1% |
| Winchester StaBALL HD | <<locked>> | 80% | 47,747 psi | 75% | 2972 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 48,994 psi | 77% | 2907 fps | 99.9% |
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 50 powders for .30-378 Weath. Mag. loaded with the .308 | 185gr | Lapua Mega. ADI AR 2218 delivers the highest muzzle velocity at 3,219 fps; across all powders the maximum-charge window runs from 1,995 fps to 3,219 fps. Accurate 8700 gives the best case fill at 100 %, and 50 of the 50 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 185.0 gr projectile in 0.308" calls for a 1:15.5 twist; slower twists will usually not stabilise this weight. Accurate 8700, Hodgdon TrailBoss, 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. ADI AR 2218, Hodgdon Retumbo, Vihtavuori N570 rank at the top here: for .30-378 Weath. Mag. with the .308 | 185gr | Lapua Mega 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.