Load Specifications
Load data in caliber .338-378 Weath. Mag. with .338 | 225gr | Nosler Expansion Tip bullet and 73 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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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>> | 92% | 55,811 psi | 87% | 2920 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 56,753 psi | 89% | 2949 fps | 100% |
| Accurate MAGPRO | <<locked>> | 90% | 54,708 psi | 86% | 3028 fps | 98.8% |
| ADI AR 2209 | <<locked>> | 88% | 54,215 psi | 85% | 2963 fps | 99.8% |
| ADI AR 2213 | <<locked>> | 92% | 55,883 psi | 88% | 3028 fps | 99.6% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 53,882 psi | 84% | 2992 fps | 99.6% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 48,298 psi | 76% | 2953 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 84% | 54,389 psi | 85% | 2956 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 90% | 57,406 psi | 90% | 3009 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 92% | 56,057 psi | 88% | 3022 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 94% | 57,406 psi | 90% | 2982 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 98% | 57,246 psi | 90% | 3051 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 88% | 54,114 psi | 85% | 3018 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 50,589 psi | 79% | 3005 fps | 96.6% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 57,072 psi | 89% | 2989 fps | 97.9% |
| Bofors RP15 | <<locked>> | 94% | 55,187 psi | 86% | 3009 fps | 99.9% |
| Bofors RP30ᴾ | <<locked>> | 100% | 56,884 psi | 89% | 3061 fps | 99.9% |
| Bofors RP5 | <<locked>> | 92% | 56,057 psi | 88% | 3022 fps | 100% |
| Bofors RP7 | <<locked>> | 82% | 54,940 psi | 86% | 2897 fps | 100% |
| Hodgdon H1000 | <<locked>> | 98% | 55,463 psi | 87% | 3015 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 82% | 54,650 psi | 86% | 2949 fps | 100% |
| Hodgdon H4350 | <<locked>> | 82% | 57,203 psi | 90% | 2966 fps | 100% |
| Hodgdon H4831 | <<locked>> | 90% | 55,477 psi | 87% | 2963 fps | 99.1% |
| Hodgdon H4831 SC | <<locked>> | 90% | 54,462 psi | 85% | 2946 fps | 99% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 54,491 psi | 85% | 2874 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 56,159 psi | 88% | 3136 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 55,317 psi | 87% | 2989 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,231 psi | 58% | 1867 fps | 100% |
| IMR 4350 | <<locked>> | 86% | 57,043 psi | 89% | 2940 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 82% | 56,449 psi | 88% | 2920 fps | 100% |
| IMR 4831 | <<locked>> | 86% | 57,188 psi | 90% | 2940 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 56,188 psi | 88% | 2943 fps | 99.3% |
| IMR 7828 SSC | <<locked>> | 92% | 53,838 psi | 84% | 3005 fps | 99.4% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 43,671 psi | 68% | 2854 fps | 98.1% |
| Lovex S065 | <<locked>> | 84% | 57,203 psi | 90% | 2917 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 55,492 psi | 87% | 2913 fps | 100% |
| Lovex S071 | <<locked>> | 98% | 57,014 psi | 89% | 2940 fps | 100% |
| Norma 204 | <<locked>> | 84% | 54,404 psi | 85% | 2943 fps | 99.8% |
| Norma 217ᴾ | <<locked>> | 100% | 44,019 psi | 69% | 2881 fps | 99.6% |
| Norma MRP | <<locked>> | 90% | 56,028 psi | 88% | 3041 fps | 100% |
| Norma URP | <<locked>> | 84% | 55,230 psi | 87% | 2933 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 54,723 psi | 86% | 3028 fps | 99.7% |
| Ramshot Hunter | <<locked>> | 84% | 54,128 psi | 85% | 2940 fps | 100% |
| Ramshot Magnum | <<locked>> | 96% | 57,464 psi | 90% | 3018 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,058 psi | 60% | 1909 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 57,000 psi | 89% | 2972 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 84% | 55,579 psi | 87% | 3002 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 57,101 psi | 89% | 3130 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 56,231 psi | 88% | 3091 fps | 99.3% |
| Rottweil R 904 | <<locked>> | 88% | 55,071 psi | 86% | 2930 fps | 99.4% |
| Rottweil R 905 | <<locked>> | 90% | 56,884 psi | 89% | 2995 fps | 100% |
| Rottweil R 907 | <<locked>> | 82% | 54,940 psi | 86% | 2897 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 84% | 57,203 psi | 90% | 2917 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 55,492 psi | 87% | 2913 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 56,318 psi | 88% | 2871 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 56,463 psi | 88% | 2989 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 56,608 psi | 89% | 2920 fps | 99.2% |
| Somchem S365 | <<locked>> | 86% | 56,101 psi | 88% | 2933 fps | 100% |
| Somchem S385 | <<locked>> | 90% | 57,377 psi | 90% | 2966 fps | 100% |
| Vihtavuori N150 | <<locked>> | 82% | 57,246 psi | 90% | 2851 fps | 100% |
| Vihtavuori N160 | <<locked>> | 84% | 56,927 psi | 89% | 2923 fps | 100% |
| Vihtavuori N165 | <<locked>> | 94% | 57,101 psi | 89% | 2946 fps | 100% |
| Vihtavuori N170 | <<locked>> | 98% | 55,912 psi | 88% | 2956 fps | 95.9% |
| Vihtavuori N550 | <<locked>> | 84% | 56,028 psi | 88% | 2930 fps | 100% |
| Vihtavuori N555 | <<locked>> | 90% | 55,637 psi | 87% | 2956 fps | 100% |
| Vihtavuori N560 | <<locked>> | 90% | 55,709 psi | 87% | 3041 fps | 99.3% |
| Vihtavuori N565 | <<locked>> | 96% | 55,840 psi | 88% | 3025 fps | 99.5% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 57,043 psi | 89% | 3091 fps | 99% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 53,853 psi | 84% | 3084 fps | 97% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 56,449 psi | 88% | 2874 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 54,795 psi | 86% | 2956 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 94% | 56,434 psi | 88% | 3074 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 92% | 57,392 psi | 90% | 2963 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% | 36,840 psi | 58% | 2589 fps | 99% |
| Accurate 4350 | <<locked>> | 80% | 49,400 psi | 77% | 2838 fps | 100% |
| Accurate MAGPRO | <<locked>> | 82% | 41,017 psi | 64% | 2769 fps | 95.7% |
| ADI AR 2209 | <<locked>> | 80% | 41,191 psi | 65% | 2723 fps | 98% |
| ADI AR 2213 | <<locked>> | 80% | 36,651 psi | 57% | 2651 fps | 95.3% |
| ADI AR 2217 | <<locked>> | 88% | 35,563 psi | 56% | 2621 fps | 95.3% |
| ADI AR 2225 | <<locked>> | 86% | 30,008 psi | 47% | 2520 fps | 96.1% |
| Alliant Reloder-16 | <<locked>> | 80% | 47,529 psi | 74% | 2848 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 41,234 psi | 65% | 2720 fps | 98% |
| Alliant Reloder-22 | <<locked>> | 80% | 36,956 psi | 58% | 2661 fps | 97% |
| Alliant Reloder-23 | <<locked>> | 80% | 35,723 psi | 56% | 2618 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 30,792 psi | 48% | 2533 fps | 98.1% |
| Alliant Reloder-26 | <<locked>> | 80% | 39,682 psi | 62% | 2769 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 98% | 46,833 psi | 73% | 2933 fps | 95.6% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 47,181 psi | 74% | 2812 fps | 95.6% |
| Bofors RP15 | <<locked>> | 80% | 34,345 psi | 54% | 2592 fps | 95.8% |
| Bofors RP30 | <<locked>> | 86% | 34,853 psi | 55% | 2635 fps | 95.4% |
| Bofors RP5 | <<locked>> | 80% | 36,956 psi | 58% | 2661 fps | 97% |
| Bofors RP7 | <<locked>> | 80% | 51,474 psi | 81% | 2841 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 84% | 33,881 psi | 53% | 2582 fps | 95.2% |
| Hodgdon H414 | <<locked>> | 80% | 51,155 psi | 80% | 2894 fps | 100% |
| Hodgdon H4350 | <<locked>> | 80% | 53,461 psi | 84% | 2907 fps | 99.8% |
| Hodgdon H4831 | <<locked>> | 80% | 39,189 psi | 61% | 2657 fps | 95.6% |
| Hodgdon H4831 SC | <<locked>> | 80% | 38,464 psi | 60% | 2644 fps | 95.3% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 44,614 psi | 70% | 2723 fps | 100% |
| Hodgdon Retumbo | 90.8 gr | 82% | 32,198 psi | 50% | 2618 fps | 95.7% |
| Hodgdon Superformance | <<locked>> | 80% | 51,387 psi | 81% | 2927 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,891 psi | 44% | 1670 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 46,992 psi | 74% | 2776 fps | 99.6% |
| IMR 4451 Enduron | <<locked>> | 80% | 52,968 psi | 83% | 2864 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 46,847 psi | 73% | 2782 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 40,785 psi | 64% | 2661 fps | 96.3% |
| IMR 7828 SSC | <<locked>> | 82% | 37,956 psi | 59% | 2694 fps | 96% |
| IMR 8133 Enduron | <<locked>> | 94% | 35,433 psi | 56% | 2667 fps | 95.4% |
| Lovex S065 | <<locked>> | 80% | 50,459 psi | 79% | 2812 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 48,718 psi | 76% | 2805 fps | 99.9% |
| Lovex S071 | <<locked>> | 80% | 31,546 psi | 49% | 2461 fps | 97.5% |
| Norma 204 | <<locked>> | 80% | 47,282 psi | 74% | 2822 fps | 99% |
| Norma 217 | <<locked>> | 90% | 30,951 psi | 49% | 2572 fps | 95.9% |
| Norma MRP | <<locked>> | 80% | 38,957 psi | 61% | 2730 fps | 98.7% |
| Norma URP | <<locked>> | 80% | 48,283 psi | 76% | 2825 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 34,838 psi | 55% | 2628 fps | 95.1% |
| Ramshot Hunter | <<locked>> | 80% | 47,181 psi | 74% | 2825 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 31,096 psi | 49% | 2510 fps | 95.6% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,558 psi | 45% | 1713 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 49,559 psi | 78% | 2861 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 47,935 psi | 75% | 2884 fps | 100% |
| ReloadSwiss RS 76 | 94.8 gr | 80% | 29,051 psi | 46% | 2516 fps | 95.2% |
| ReloadSwiss RS 80 | <<locked>> | 92% | 41,104 psi | 64% | 2812 fps | 96.1% |
| Rottweil R 904 | <<locked>> | 80% | 42,366 psi | 66% | 2700 fps | 97.3% |
| Rottweil R 905 | <<locked>> | 80% | 40,538 psi | 64% | 2703 fps | 98% |
| Rottweil R 907 | <<locked>> | 80% | 51,474 psi | 81% | 2841 fps | 99.9% |
| Shooters World Long Rifle | <<locked>> | 80% | 50,459 psi | 79% | 2812 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 48,718 psi | 76% | 2805 fps | 99.9% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 49,385 psi | 77% | 2762 fps | 99.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 40,205 psi | 63% | 2700 fps | 97.9% |
| Somchem S361 | <<locked>> | 80% | 43,134 psi | 68% | 2687 fps | 96.8% |
| Somchem S365 | <<locked>> | 80% | 45,571 psi | 71% | 2776 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 40,944 psi | 64% | 2680 fps | 98.7% |
| Vihtavuori N150 | <<locked>> | 80% | 53,606 psi | 84% | 2802 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 49,835 psi | 78% | 2818 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 35,592 psi | 56% | 2556 fps | 97.1% |
| Vihtavuori N170 | <<locked>> | 96% | 52,141 psi | 82% | 2894 fps | 95% |
| Vihtavuori N550 | <<locked>> | 80% | 49,095 psi | 77% | 2822 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 39,885 psi | 63% | 2694 fps | 100% |
| Vihtavuori N560 | 91.9 gr | 80% | 38,986 psi | 61% | 2723 fps | 95.7% |
| Vihtavuori N565 | <<locked>> | 84% | 36,680 psi | 57% | 2654 fps | 95.2% |
| Vihtavuori N568 | <<locked>> | 92% | 42,409 psi | 66% | 2825 fps | 95.9% |
| Vihtavuori N570 | <<locked>> | 96% | 46,441 psi | 73% | 2946 fps | 95% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 49,124 psi | 77% | 2772 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 51,300 psi | 80% | 2897 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 32,227 psi | 51% | 2648 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 37,579 psi | 59% | 2608 fps | 97.1% |
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 78 powders for .338-378 Weath. Mag. loaded with the .338 | 225gr | Nosler Expansion Tip. Hodgdon Retumbo delivers the highest muzzle velocity at 3,136 fps; across all powders the maximum-charge window runs from 1,867 fps to 3,136 fps. ADI AR 2217 gives the best case fill at 100 %, and 78 of the 78 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 1:12.0 twist; slower twists will usually not stabilise this weight. ADI AR 2217, 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. Hodgdon Retumbo, ReloadSwiss RS 76, Vihtavuori N560 rank at the top here: for .338-378 Weath. Mag. with the .338 | 225gr | Nosler Expansion Tip they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, ADI AR 2218, Alliant Reloder-50, IMR 7977 Enduron 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.