Load Specifications
Load data in caliber .338-378 Weath. Mag. with .338 | 225gr | CutEdge MTH 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 Vihtavuori N560.
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% | 55,303 psi | 87% | 2913 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 56,362 psi | 88% | 2943 fps | 100% |
| Accurate MAGPRO | <<locked>> | 90% | 54,230 psi | 85% | 3018 fps | 98.8% |
| ADI AR 2209 | <<locked>> | 90% | 57,551 psi | 90% | 3012 fps | 100% |
| ADI AR 2213 | <<locked>> | 92% | 55,434 psi | 87% | 3022 fps | 99.5% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 53,476 psi | 84% | 2982 fps | 99.6% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 47,921 psi | 75% | 2946 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 86% | 57,624 psi | 90% | 3002 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 90% | 56,927 psi | 89% | 2999 fps | 99.9% |
| Alliant Reloder-22 | <<locked>> | 92% | 55,564 psi | 87% | 3015 fps | 99.9% |
| Alliant Reloder-23 | <<locked>> | 94% | 57,058 psi | 89% | 2976 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 98% | 56,739 psi | 89% | 3045 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 90% | 57,740 psi | 90% | 3071 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 50,038 psi | 78% | 2995 fps | 96.4% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 56,753 psi | 89% | 2982 fps | 97.8% |
| Bofors RP15 | <<locked>> | 94% | 54,752 psi | 86% | 2999 fps | 99.9% |
| Bofors RP30ᴾ | <<locked>> | 100% | 56,434 psi | 88% | 3054 fps | 99.8% |
| Bofors RP5 | <<locked>> | 92% | 55,564 psi | 87% | 3015 fps | 99.9% |
| Bofors RP7 | <<locked>> | 82% | 54,607 psi | 86% | 2890 fps | 100% |
| Hodgdon H1000 | <<locked>> | 98% | 55,042 psi | 86% | 3009 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 82% | 54,302 psi | 85% | 2946 fps | 100% |
| Hodgdon H4350 | <<locked>> | 82% | 56,855 psi | 89% | 2959 fps | 100% |
| Hodgdon H4831 | <<locked>> | 90% | 54,998 psi | 86% | 2953 fps | 99% |
| Hodgdon H4831 SC | <<locked>> | 90% | 53,998 psi | 85% | 2940 fps | 98.9% |
| Hodgdon Hybrid 100V | <<locked>> | 88% | 57,740 psi | 90% | 2917 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 55,680 psi | 87% | 3130 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 54,853 psi | 86% | 2982 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,275 psi | 58% | 1864 fps | 100% |
| IMR 4350 | <<locked>> | 86% | 56,536 psi | 89% | 2933 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 82% | 56,115 psi | 88% | 2913 fps | 100% |
| IMR 4831 | <<locked>> | 86% | 56,637 psi | 89% | 2933 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 55,941 psi | 88% | 2940 fps | 99.2% |
| IMR 7828 SSC | <<locked>> | 94% | 57,464 psi | 90% | 3061 fps | 99.7% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 43,250 psi | 68% | 2844 fps | 98% |
| Lovex S065 | <<locked>> | 84% | 56,855 psi | 89% | 2910 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 55,158 psi | 86% | 2910 fps | 100% |
| Lovex S071 | <<locked>> | 98% | 56,724 psi | 89% | 2933 fps | 100% |
| Norma 204 | <<locked>> | 84% | 54,099 psi | 85% | 2936 fps | 99.7% |
| Norma 217ᴾ | <<locked>> | 100% | 43,569 psi | 68% | 2874 fps | 99.6% |
| Norma MRP | <<locked>> | 90% | 55,506 psi | 87% | 3035 fps | 100% |
| Norma URP | <<locked>> | 84% | 54,868 psi | 86% | 2927 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 54,201 psi | 85% | 3018 fps | 99.6% |
| Ramshot Hunter | <<locked>> | 86% | 57,450 psi | 90% | 2989 fps | 100% |
| Ramshot Magnum | <<locked>> | 96% | 56,797 psi | 89% | 3009 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,101 psi | 60% | 1909 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 56,652 psi | 89% | 2969 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 84% | 55,201 psi | 87% | 2999 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 56,449 psi | 88% | 3120 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 55,608 psi | 87% | 3077 fps | 99.2% |
| Rottweil R 904 | <<locked>> | 88% | 54,781 psi | 86% | 2923 fps | 99.4% |
| Rottweil R 905 | <<locked>> | 90% | 56,536 psi | 89% | 2989 fps | 100% |
| Rottweil R 907 | <<locked>> | 82% | 54,607 psi | 86% | 2890 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 84% | 56,855 psi | 89% | 2910 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 55,158 psi | 86% | 2910 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 56,028 psi | 88% | 2864 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 56,115 psi | 88% | 2986 fps | 99.9% |
| Somchem S361 | <<locked>> | 88% | 56,188 psi | 88% | 2917 fps | 99.1% |
| Somchem S365 | <<locked>> | 86% | 55,535 psi | 87% | 2927 fps | 100% |
| Somchem S385 | <<locked>> | 90% | 56,884 psi | 89% | 2959 fps | 100% |
| Vihtavuori N150 | <<locked>> | 82% | 56,884 psi | 89% | 2844 fps | 100% |
| Vihtavuori N160 | <<locked>> | 84% | 56,550 psi | 89% | 2917 fps | 100% |
| Vihtavuori N165 | <<locked>> | 94% | 56,652 psi | 89% | 2940 fps | 100% |
| Vihtavuori N550 | <<locked>> | 84% | 55,709 psi | 87% | 2923 fps | 100% |
| Vihtavuori N555 | <<locked>> | 90% | 55,274 psi | 87% | 2953 fps | 100% |
| Vihtavuori N560 | <<locked>> | 90% | 55,216 psi | 87% | 3035 fps | 99.3% |
| Vihtavuori N565 | <<locked>> | 96% | 55,405 psi | 87% | 3018 fps | 99.4% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 56,391 psi | 88% | 3081 fps | 98.9% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 53,258 psi | 83% | 3074 fps | 96.8% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 56,173 psi | 88% | 2871 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 54,447 psi | 85% | 2946 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 94% | 55,825 psi | 87% | 3064 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 92% | 56,942 psi | 89% | 2956 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% | 36,506 psi | 57% | 2579 fps | 98.9% |
| Accurate 4350 | <<locked>> | 80% | 49,008 psi | 77% | 2831 fps | 100% |
| Accurate MAGPRO | <<locked>> | 82% | 40,567 psi | 64% | 2759 fps | 95.6% |
| ADI AR 2209 | <<locked>> | 80% | 40,872 psi | 64% | 2717 fps | 97.9% |
| ADI AR 2213 | <<locked>> | 80% | 36,361 psi | 57% | 2644 fps | 95.2% |
| ADI AR 2217 | <<locked>> | 88% | 35,346 psi | 55% | 2615 fps | 95.1% |
| ADI AR 2225 | <<locked>> | 86% | 29,791 psi | 47% | 2513 fps | 95.9% |
| Alliant Reloder-16 | <<locked>> | 80% | 47,137 psi | 74% | 2841 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 40,915 psi | 64% | 2713 fps | 97.9% |
| Alliant Reloder-22 | <<locked>> | 80% | 36,637 psi | 57% | 2651 fps | 96.8% |
| Alliant Reloder-23 | <<locked>> | 80% | 35,389 psi | 55% | 2612 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 30,516 psi | 48% | 2526 fps | 98% |
| Alliant Reloder-26 | <<locked>> | 80% | 39,334 psi | 62% | 2762 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 98% | 46,485 psi | 73% | 2927 fps | 95.4% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 46,992 psi | 74% | 2808 fps | 95.5% |
| Bofors RP15 | <<locked>> | 80% | 34,040 psi | 53% | 2585 fps | 95.7% |
| Bofors RP30 | <<locked>> | 86% | 34,534 psi | 54% | 2628 fps | 95.2% |
| Bofors RP5 | <<locked>> | 80% | 36,637 psi | 57% | 2651 fps | 96.8% |
| Bofors RP7 | <<locked>> | 80% | 51,285 psi | 80% | 2838 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 84% | 33,634 psi | 53% | 2572 fps | 95% |
| Hodgdon H414 | <<locked>> | 80% | 50,792 psi | 80% | 2887 fps | 100% |
| Hodgdon H4350 | <<locked>> | 80% | 53,113 psi | 83% | 2900 fps | 99.8% |
| Hodgdon H4831 | <<locked>> | 80% | 38,899 psi | 61% | 2651 fps | 95.5% |
| Hodgdon H4831 SC | <<locked>> | 80% | 38,159 psi | 60% | 2635 fps | 95.2% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 44,237 psi | 69% | 2717 fps | 100% |
| Hodgdon Retumbo | 90.2 gr | 82% | 31,937 psi | 50% | 2608 fps | 95.5% |
| Hodgdon Superformance | <<locked>> | 80% | 50,908 psi | 80% | 2920 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,862 psi | 44% | 1670 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 46,688 psi | 73% | 2769 fps | 99.6% |
| IMR 4451 Enduron | <<locked>> | 80% | 52,808 psi | 83% | 2861 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 46,470 psi | 73% | 2776 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 40,495 psi | 63% | 2654 fps | 96.2% |
| IMR 7828 SSC | <<locked>> | 82% | 37,666 psi | 59% | 2687 fps | 95.8% |
| IMR 8133 Enduron | <<locked>> | 94% | 35,157 psi | 55% | 2664 fps | 95.3% |
| Lovex S065 | <<locked>> | 80% | 50,125 psi | 79% | 2808 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 48,399 psi | 76% | 2799 fps | 99.9% |
| Lovex S071 | <<locked>> | 80% | 31,256 psi | 49% | 2454 fps | 97.4% |
| Norma 204 | <<locked>> | 80% | 47,123 psi | 74% | 2818 fps | 99% |
| Norma 217 | <<locked>> | 90% | 30,574 psi | 48% | 2562 fps | 95.7% |
| Norma MRP | <<locked>> | 80% | 38,638 psi | 61% | 2726 fps | 98.6% |
| Norma URP | <<locked>> | 80% | 47,935 psi | 75% | 2818 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 34,563 psi | 54% | 2621 fps | 95% |
| Ramshot Hunter | <<locked>> | 80% | 46,992 psi | 74% | 2822 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 30,734 psi | 48% | 2500 fps | 95.4% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,543 psi | 45% | 1709 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 49,211 psi | 77% | 2854 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 47,587 psi | 75% | 2877 fps | 100% |
| ReloadSwiss RS 76 | 94.2 gr | 80% | 28,805 psi | 45% | 2510 fps | 95% |
| ReloadSwiss RS 80 | <<locked>> | 92% | 40,712 psi | 64% | 2805 fps | 95.9% |
| Rottweil R 904 | <<locked>> | 80% | 42,163 psi | 66% | 2697 fps | 97.2% |
| Rottweil R 905 | <<locked>> | 80% | 40,190 psi | 63% | 2697 fps | 97.9% |
| Rottweil R 907 | <<locked>> | 80% | 51,285 psi | 80% | 2838 fps | 99.9% |
| Shooters World Long Rifle | <<locked>> | 80% | 50,125 psi | 79% | 2808 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 48,399 psi | 76% | 2799 fps | 99.9% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 49,066 psi | 77% | 2756 fps | 99.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 39,856 psi | 62% | 2690 fps | 97.8% |
| Somchem S361 | <<locked>> | 80% | 42,844 psi | 67% | 2680 fps | 96.7% |
| Somchem S365 | <<locked>> | 80% | 45,208 psi | 71% | 2769 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 40,640 psi | 64% | 2677 fps | 98.6% |
| Vihtavuori N150 | <<locked>> | 80% | 53,258 psi | 83% | 2795 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 49,472 psi | 78% | 2812 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 35,331 psi | 55% | 2549 fps | 97% |
| Vihtavuori N550 | <<locked>> | 80% | 48,762 psi | 76% | 2815 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 39,552 psi | 62% | 2687 fps | 100% |
| Vihtavuori N560 | 91.3 gr | 80% | 38,667 psi | 61% | 2713 fps | 95.6% |
| Vihtavuori N565 | <<locked>> | 84% | 36,405 psi | 57% | 2648 fps | 95.1% |
| Vihtavuori N568 | <<locked>> | 92% | 42,003 psi | 66% | 2818 fps | 95.7% |
| Vihtavuori N570 | <<locked>> | 98% | 49,414 psi | 77% | 3002 fps | 95.8% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 48,834 psi | 77% | 2766 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 50,952 psi | 80% | 2890 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 31,937 psi | 50% | 2641 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 37,289 psi | 58% | 2602 fps | 97% |
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 | 225gr | CutEdge MTH. Hodgdon Retumbo delivers the highest muzzle velocity at 3,130 fps; across all powders the maximum-charge window runs from 1,864 fps to 3,130 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 225.0 gr projectile in 0.338" calls for a 1:11.0 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, Vihtavuori N560 rank at the top here: for .338-378 Weath. Mag. with the .338 | 225gr | CutEdge MTH 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.