Load Specifications
Load data in caliber .30-378 Weath. Mag. with .308 | 220gr | Winchester Silvertip bullet and 33 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ADI AR 2218, IMR 8133 Enduron and Alliant Reloder-50.
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 8700 | <<locked>> | 96% | 53,911 psi | 84% | 2864 fps | 99.4% |
| ADI AR 2217 | <<locked>> | 88% | 56,550 psi | 89% | 2884 fps | 100% |
| ADI AR 2218 | <<locked>> | 90% | 53,505 psi | 84% | 2966 fps | 99.8% |
| ADI AR 2225 | <<locked>> | 90% | 57,087 psi | 89% | 2910 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 84% | 56,739 psi | 89% | 2864 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 88% | 55,709 psi | 87% | 2943 fps | 99.8% |
| Alliant Reloder-50 | <<locked>> | 92% | 56,434 psi | 88% | 2949 fps | 99.6% |
| Baschieri & Pellagri 109 | <<locked>> | 82% | 55,637 psi | 87% | 2851 fps | 99.8% |
| Bofors RP15 | <<locked>> | 82% | 56,362 psi | 88% | 2874 fps | 100% |
| Bofors RP30 | <<locked>> | 86% | 56,724 psi | 89% | 2900 fps | 100% |
| Hodgdon H1000 | <<locked>> | 84% | 53,809 psi | 84% | 2838 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 84% | 57,305 psi | 90% | 2966 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 38,421 psi | 60% | 1850 fps | 100% |
| Hodgdon US 869 | <<locked>> | 94% | 54,128 psi | 85% | 2864 fps | 96.3% |
| IMR 7977 Enduron | <<locked>> | 86% | 56,420 psi | 88% | 2822 fps | 98.1% |
| IMR 8133 Enduron | <<locked>> | 92% | 56,144 psi | 88% | 2907 fps | 100% |
| Lovex D100 | <<locked>> | 88% | 54,578 psi | 86% | 2822 fps | 96.9% |
| Lovex S071 | <<locked>> | 84% | 55,259 psi | 87% | 2762 fps | 100% |
| Norma 217 | <<locked>> | 90% | 54,302 psi | 85% | 2871 fps | 100% |
| Ramshot LRT | <<locked>> | 92% | 56,927 psi | 89% | 2966 fps | 97.1% |
| Ramshot Magnum | <<locked>> | 82% | 55,056 psi | 86% | 2825 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 39,610 psi | 62% | 1896 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 82% | 53,635 psi | 84% | 2887 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 86% | 56,579 psi | 89% | 2933 fps | 100% |
| Shooters World 50 BMG | <<locked>> | 88% | 54,578 psi | 86% | 2822 fps | 96.9% |
| SNPE Vectan SP 13 | <<locked>> | 96% | 55,303 psi | 87% | 2867 fps | 99.3% |
| Vihtavuori 20N29ᴾ | <<locked>> | 100% | 56,666 psi | 89% | 2913 fps | 98.6% |
| Vihtavuori 24N41 | <<locked>> | 92% | 54,665 psi | 86% | 2874 fps | 96.4% |
| Vihtavuori N165 | <<locked>> | 82% | 56,826 psi | 89% | 2805 fps | 100% |
| Vihtavuori N170 | <<locked>> | 86% | 56,579 psi | 89% | 2861 fps | 99.1% |
| Vihtavuori N565 | <<locked>> | 82% | 54,433 psi | 85% | 2851 fps | 100% |
| Vihtavuori N568 | <<locked>> | 86% | 56,840 psi | 89% | 2936 fps | 100% |
| Vihtavuori N570 | <<locked>> | 86% | 54,868 psi | 86% | 2946 fps | 99.5% |
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 8700 | <<locked>> | 86% | 37,550 psi | 59% | 2552 fps | 95.5% |
| ADI AR 2217 | <<locked>> | 80% | 42,772 psi | 67% | 2654 fps | 99.8% |
| ADI AR 2218 | 99.9 gr | 80% | 36,927 psi | 58% | 2615 fps | 95.8% |
| ADI AR 2225 | <<locked>> | 80% | 40,364 psi | 63% | 2635 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 49,559 psi | 78% | 2756 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 80% | 41,495 psi | 65% | 2674 fps | 97.3% |
| Alliant Reloder-50 | 103.9 gr | 82% | 39,218 psi | 61% | 2615 fps | 96% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 52,112 psi | 82% | 2795 fps | 99.5% |
| Bofors RP15 | <<locked>> | 80% | 52,837 psi | 83% | 2818 fps | 100% |
| Bofors RP30 | <<locked>> | 80% | 46,354 psi | 73% | 2730 fps | 100% |
| Hodgdon H1000 | <<locked>> | 80% | 46,731 psi | 73% | 2726 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 80% | 49,719 psi | 78% | 2848 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,935 psi | 45% | 1657 fps | 100% |
| Hodgdon US 869 | <<locked>> | 92% | 50,517 psi | 79% | 2802 fps | 95.4% |
| IMR 7977 Enduron | <<locked>> | 80% | 46,470 psi | 73% | 2644 fps | 95.9% |
| IMR 8133 Enduron | 91.7 gr | 80% | 37,536 psi | 59% | 2562 fps | 99% |
| Lovex D100 | <<locked>> | 84% | 47,340 psi | 74% | 2694 fps | 95.1% |
| Lovex S071 | <<locked>> | 80% | 48,805 psi | 76% | 2664 fps | 100% |
| Norma 217 | <<locked>> | 80% | 38,493 psi | 60% | 2589 fps | 100% |
| Ramshot LRT | <<locked>> | 88% | 49,385 psi | 77% | 2831 fps | 95.2% |
| Ramshot Magnum | <<locked>> | 80% | 51,126 psi | 80% | 2766 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,820 psi | 47% | 1696 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 49,763 psi | 78% | 2828 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 80% | 45,426 psi | 71% | 2740 fps | 99.6% |
| Shooters World 50 BMG | <<locked>> | 84% | 47,340 psi | 74% | 2694 fps | 95.1% |
| SNPE Vectan SP 13 | <<locked>> | 86% | 39,537 psi | 62% | 2572 fps | 95.8% |
| Vihtavuori 20N29 | <<locked>> | 92% | 42,772 psi | 67% | 2661 fps | 95.2% |
| Vihtavuori 24N41 | <<locked>> | 90% | 50,923 psi | 80% | 2808 fps | 95.5% |
| Vihtavuori N165 | <<locked>> | 80% | 53,200 psi | 83% | 2749 fps | 100% |
| Vihtavuori N170 | <<locked>> | 80% | 46,238 psi | 72% | 2680 fps | 97.3% |
| Vihtavuori N565 | <<locked>> | 80% | 50,908 psi | 80% | 2795 fps | 100% |
| Vihtavuori N568 | <<locked>> | 80% | 46,021 psi | 72% | 2746 fps | 99.4% |
| Vihtavuori N570 | <<locked>> | 80% | 44,237 psi | 69% | 2746 fps | 97.7% |
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 33 powders for .30-378 Weath. Mag. loaded with the .308 | 220gr | Winchester Silvertip. ADI AR 2218 delivers the highest muzzle velocity at 2,966 fps; across all powders the maximum-charge window runs from 1,850 fps to 2,966 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 33 of the 33 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 220.0 gr projectile in 0.308" calls for a 1:6.0 twist; slower twists will usually not stabilise this weight. Hodgdon TrailBoss, ReloadSwiss RS 14, Vihtavuori 20N29 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, IMR 8133 Enduron, Alliant Reloder-50 rank at the top here: for .30-378 Weath. Mag. with the .308 | 220gr | Winchester Silvertip 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.