Load Specifications
Load data in caliber .338-378 Weath. Mag. with .338 | 210gr | Swift Scirocco bullet and 72 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Hodgdon Retumbo, ReloadSwiss RS 76 and Accurate MAGPRO.
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>> | 92% | 56,478 psi | 89% | 3018 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 57,290 psi | 90% | 3048 fps | 100% |
| Accurate MAGPRO | <<locked>> | 90% | 55,056 psi | 86% | 3120 fps | 98.5% |
| ADI AR 2209 | <<locked>> | 88% | 54,404 psi | 85% | 3054 fps | 99.6% |
| ADI AR 2213 | <<locked>> | 92% | 56,072 psi | 88% | 3123 fps | 99.3% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 54,128 psi | 85% | 3081 fps | 99.4% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 48,718 psi | 76% | 3041 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 84% | 54,505 psi | 85% | 3051 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 90% | 57,595 psi | 90% | 3100 fps | 99.9% |
| Alliant Reloder-22 | <<locked>> | 92% | 56,304 psi | 88% | 3114 fps | 99.9% |
| Alliant Reloder-23 | <<locked>> | 94% | 57,725 psi | 90% | 3077 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 98% | 57,522 psi | 90% | 3146 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 88% | 54,404 psi | 85% | 3114 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 51,111 psi | 80% | 3094 fps | 96.1% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 57,232 psi | 90% | 3074 fps | 97.5% |
| Bofors RP15 | <<locked>> | 94% | 55,492 psi | 87% | 3100 fps | 99.8% |
| Bofors RP30ᴾ | <<locked>> | 100% | 57,363 psi | 90% | 3156 fps | 99.7% |
| Bofors RP5 | <<locked>> | 92% | 56,304 psi | 88% | 3114 fps | 99.9% |
| Bofors RP7 | <<locked>> | 82% | 55,347 psi | 87% | 2992 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 98% | 55,825 psi | 87% | 3110 fps | 99.8% |
| Hodgdon H414 | <<locked>> | 82% | 54,940 psi | 86% | 3045 fps | 100% |
| Hodgdon H4350 | <<locked>> | 82% | 57,319 psi | 90% | 3058 fps | 99.9% |
| Hodgdon H4831 | <<locked>> | 90% | 55,782 psi | 87% | 3054 fps | 98.8% |
| Hodgdon H4831 SC | <<locked>> | 90% | 54,650 psi | 86% | 3038 fps | 98.7% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 54,650 psi | 86% | 2966 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 56,347 psi | 88% | 3232 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 55,521 psi | 87% | 3081 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,260 psi | 58% | 1939 fps | 100% |
| IMR 4350 | <<locked>> | 86% | 57,145 psi | 90% | 3031 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 82% | 56,666 psi | 89% | 3015 fps | 100% |
| IMR 4831 | <<locked>> | 86% | 57,493 psi | 90% | 3038 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 56,434 psi | 88% | 3035 fps | 99% |
| IMR 7828 SSC | <<locked>> | 92% | 54,085 psi | 85% | 3097 fps | 99.2% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 44,164 psi | 69% | 2943 fps | 97.7% |
| Lovex S065 | <<locked>> | 84% | 57,522 psi | 90% | 3012 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 55,796 psi | 87% | 3009 fps | 100% |
| Lovex S071 | <<locked>> | 98% | 57,624 psi | 90% | 3035 fps | 100% |
| Norma 204 | <<locked>> | 84% | 54,679 psi | 86% | 3035 fps | 99.6% |
| Norma 217ᴾ | <<locked>> | 100% | 44,512 psi | 70% | 2972 fps | 99.4% |
| Norma MRP | <<locked>> | 90% | 56,260 psi | 88% | 3136 fps | 100% |
| Norma URP | <<locked>> | 84% | 55,419 psi | 87% | 3028 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 54,955 psi | 86% | 3120 fps | 99.5% |
| Ramshot Hunter | <<locked>> | 84% | 54,447 psi | 85% | 3035 fps | 100% |
| Ramshot Magnum | <<locked>> | 94% | 53,490 psi | 84% | 3048 fps | 99.9% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,203 psi | 60% | 1985 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 57,348 psi | 90% | 3071 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 84% | 55,796 psi | 87% | 3100 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 57,493 psi | 90% | 3225 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 56,724 psi | 89% | 3179 fps | 99% |
| Rottweil R 904 | <<locked>> | 88% | 55,347 psi | 87% | 3022 fps | 99.2% |
| Rottweil R 905 | <<locked>> | 90% | 57,217 psi | 90% | 3091 fps | 99.9% |
| Rottweil R 907 | <<locked>> | 82% | 55,347 psi | 87% | 2992 fps | 99.9% |
| Shooters World Long Rifle | <<locked>> | 84% | 57,522 psi | 90% | 3012 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 55,796 psi | 87% | 3009 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 56,695 psi | 89% | 2963 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 56,782 psi | 89% | 3087 fps | 99.9% |
| Somchem S361 | <<locked>> | 88% | 56,855 psi | 89% | 3012 fps | 98.9% |
| Somchem S365 | <<locked>> | 86% | 56,333 psi | 88% | 3028 fps | 100% |
| Somchem S385 | <<locked>> | 90% | 57,696 psi | 90% | 3058 fps | 100% |
| Vihtavuori N150 | <<locked>> | 82% | 57,595 psi | 90% | 2949 fps | 100% |
| Vihtavuori N160 | <<locked>> | 84% | 57,188 psi | 90% | 3018 fps | 100% |
| Vihtavuori N165 | <<locked>> | 94% | 57,363 psi | 90% | 3038 fps | 100% |
| Vihtavuori N550 | <<locked>> | 84% | 56,318 psi | 88% | 3025 fps | 100% |
| Vihtavuori N555 | <<locked>> | 90% | 56,231 psi | 88% | 3054 fps | 100% |
| Vihtavuori N560 | <<locked>> | 90% | 55,898 psi | 88% | 3133 fps | 99% |
| Vihtavuori N565 | <<locked>> | 96% | 56,289 psi | 88% | 3117 fps | 99.2% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 57,305 psi | 90% | 3182 fps | 98.7% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 54,172 psi | 85% | 3173 fps | 96.5% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 56,666 psi | 89% | 2966 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 55,085 psi | 86% | 3048 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 94% | 56,594 psi | 89% | 3166 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 92% | 57,609 psi | 90% | 3054 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% | 37,521 psi | 59% | 2677 fps | 98.7% |
| Accurate 4350 | <<locked>> | 80% | 49,908 psi | 78% | 2936 fps | 100% |
| Accurate MAGPRO | 99.2 gr | 82% | 41,452 psi | 65% | 2854 fps | 95.2% |
| ADI AR 2209 | <<locked>> | 80% | 41,466 psi | 65% | 2808 fps | 97.6% |
| ADI AR 2213 | <<locked>> | 82% | 39,726 psi | 62% | 2799 fps | 95.8% |
| ADI AR 2217 | <<locked>> | 90% | 38,566 psi | 60% | 2766 fps | 95.8% |
| ADI AR 2225 | <<locked>> | 86% | 30,618 psi | 48% | 2602 fps | 95.6% |
| Alliant Reloder-16 | <<locked>> | 80% | 47,645 psi | 75% | 2940 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 41,510 psi | 65% | 2805 fps | 97.6% |
| Alliant Reloder-22 | <<locked>> | 80% | 37,449 psi | 59% | 2746 fps | 96.5% |
| Alliant Reloder-23 | <<locked>> | 80% | 36,085 psi | 57% | 2703 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 31,270 psi | 49% | 2615 fps | 97.7% |
| Alliant Reloder-26 | <<locked>> | 80% | 40,118 psi | 63% | 2858 fps | 99.9% |
| Alliant Reloder-33 | <<locked>> | 98% | 47,340 psi | 74% | 3022 fps | 95% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 47,442 psi | 74% | 2894 fps | 95.1% |
| Bofors RP15 | <<locked>> | 80% | 34,809 psi | 55% | 2680 fps | 95.3% |
| Bofors RP30 | <<locked>> | 88% | 37,898 psi | 59% | 2782 fps | 95.9% |
| Bofors RP5 | <<locked>> | 80% | 37,449 psi | 59% | 2746 fps | 96.5% |
| Bofors RP7 | <<locked>> | 80% | 51,822 psi | 81% | 2936 fps | 99.8% |
| Hodgdon H1000 | <<locked>> | 86% | 36,753 psi | 58% | 2726 fps | 95.7% |
| Hodgdon H414 | <<locked>> | 80% | 51,430 psi | 81% | 2989 fps | 99.9% |
| Hodgdon H4350 | <<locked>> | 80% | 53,722 psi | 84% | 3002 fps | 99.7% |
| Hodgdon H4831 | <<locked>> | 80% | 39,552 psi | 62% | 2743 fps | 95.1% |
| Hodgdon H4831 SC | <<locked>> | 82% | 41,611 psi | 65% | 2789 fps | 95.7% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 44,904 psi | 70% | 2815 fps | 100% |
| Hodgdon Retumbo | 93.8 gr | 82% | 32,692 psi | 51% | 2700 fps | 95.1% |
| Hodgdon Superformance | <<locked>> | 80% | 51,590 psi | 81% | 3018 fps | 99.9% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,992 psi | 44% | 1739 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 47,253 psi | 74% | 2864 fps | 99.4% |
| IMR 4451 Enduron | <<locked>> | 80% | 53,156 psi | 83% | 2959 fps | 99.9% |
| IMR 4831 | <<locked>> | 80% | 47,239 psi | 74% | 2874 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 41,104 psi | 64% | 2746 fps | 95.8% |
| IMR 7828 SSC | <<locked>> | 82% | 38,319 psi | 60% | 2779 fps | 95.4% |
| IMR 8133 Enduron | <<locked>> | 94% | 36,027 psi | 56% | 2756 fps | 95% |
| Lovex S065 | <<locked>> | 80% | 50,749 psi | 80% | 2904 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 49,182 psi | 77% | 2900 fps | 99.8% |
| Lovex S071 | <<locked>> | 80% | 32,343 psi | 51% | 2549 fps | 97.3% |
| Norma 204 | <<locked>> | 80% | 47,674 psi | 75% | 2913 fps | 98.7% |
| Norma 217 | <<locked>> | 90% | 31,560 psi | 49% | 2657 fps | 95.4% |
| Norma MRP | <<locked>> | 80% | 39,436 psi | 62% | 2822 fps | 98.4% |
| Norma URP | <<locked>> | 80% | 48,631 psi | 76% | 2917 fps | 100% |
| Ramshot Grand | <<locked>> | 82% | 38,000 psi | 60% | 2782 fps | 95.7% |
| Ramshot Hunter | <<locked>> | 80% | 47,616 psi | 75% | 2920 fps | 99.9% |
| Ramshot Magnum | <<locked>> | 80% | 31,647 psi | 50% | 2592 fps | 95.1% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,674 psi | 45% | 1781 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 50,053 psi | 78% | 2959 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 48,153 psi | 75% | 2979 fps | 100% |
| ReloadSwiss RS 76 | 100.4 gr | 82% | 31,821 psi | 50% | 2671 fps | 96.1% |
| ReloadSwiss RS 80 | <<locked>> | 92% | 41,597 psi | 65% | 2897 fps | 95.6% |
| Rottweil R 904 | <<locked>> | 80% | 42,685 psi | 67% | 2789 fps | 96.8% |
| Rottweil R 905 | <<locked>> | 80% | 40,901 psi | 64% | 2792 fps | 97.6% |
| Rottweil R 907 | <<locked>> | 80% | 51,822 psi | 81% | 2936 fps | 99.8% |
| Shooters World Long Rifle | <<locked>> | 80% | 50,749 psi | 80% | 2904 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 49,182 psi | 77% | 2900 fps | 99.8% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 49,734 psi | 78% | 2854 fps | 99.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 40,596 psi | 64% | 2785 fps | 97.5% |
| Somchem S361 | <<locked>> | 80% | 43,497 psi | 68% | 2772 fps | 96.3% |
| Somchem S365 | <<locked>> | 80% | 45,963 psi | 72% | 2871 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 41,495 psi | 65% | 2769 fps | 98.4% |
| Vihtavuori N150 | <<locked>> | 80% | 53,969 psi | 85% | 2897 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 50,111 psi | 79% | 2910 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 36,042 psi | 56% | 2638 fps | 96.6% |
| Vihtavuori N550 | <<locked>> | 80% | 49,501 psi | 78% | 2917 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 40,393 psi | 63% | 2782 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 39,436 psi | 62% | 2808 fps | 95.2% |
| Vihtavuori N565 | <<locked>> | 86% | 39,943 psi | 63% | 2805 fps | 95.7% |
| Vihtavuori N568 | <<locked>> | 92% | 42,960 psi | 67% | 2913 fps | 95.3% |
| Vihtavuori N570 | <<locked>> | 98% | 50,314 psi | 79% | 3100 fps | 95.4% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 49,298 psi | 77% | 2861 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 51,576 psi | 81% | 2992 fps | 99.9% |
| Winchester StaBALL HD | <<locked>> | 80% | 32,750 psi | 51% | 2740 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 38,043 psi | 60% | 2694 fps | 96.6% |
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 72 powders for .338-378 Weath. Mag. loaded with the .338 | 210gr | Swift Scirocco. Hodgdon Retumbo delivers the highest muzzle velocity at 3,232 fps; across all powders the maximum-charge window runs from 1,939 fps to 3,232 fps. ADI AR 2217 gives the best case fill at 100 %, and 72 of the 72 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 58–90 %, leaving at least 10 % headroom. The 210.0 gr projectile in 0.338" calls for a 1:13.5 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2225, Alliant Reloder-33 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. Hodgdon Retumbo, ReloadSwiss RS 76, Accurate MAGPRO rank at the top here: for .338-378 Weath. Mag. with the .338 | 210gr | Swift Scirocco 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.