Load Specifications
Load data in caliber .338-378 Weath. Mag. with .338 | 225gr | Barnes TAC-TX BT 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 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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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% | 55,941 psi | 88% | 2923 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 56,913 psi | 89% | 2949 fps | 100% |
| Accurate MAGPRO | <<locked>> | 90% | 54,810 psi | 86% | 3028 fps | 98.9% |
| ADI AR 2209 | <<locked>> | 88% | 54,346 psi | 85% | 2966 fps | 99.8% |
| ADI AR 2213 | <<locked>> | 92% | 55,999 psi | 88% | 3031 fps | 99.6% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 53,983 psi | 85% | 2992 fps | 99.6% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 48,399 psi | 76% | 2953 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 84% | 54,375 psi | 85% | 2956 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 90% | 57,522 psi | 90% | 3009 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 92% | 56,173 psi | 88% | 3022 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 94% | 57,537 psi | 90% | 2982 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 98% | 57,377 psi | 90% | 3054 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 88% | 54,244 psi | 85% | 3022 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 50,865 psi | 80% | 3009 fps | 96.7% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 57,188 psi | 90% | 2989 fps | 97.9% |
| Bofors RP15 | <<locked>> | 94% | 55,303 psi | 87% | 3009 fps | 99.9% |
| Bofors RP30ᴾ | <<locked>> | 100% | 57,014 psi | 89% | 3064 fps | 99.9% |
| Bofors RP5 | <<locked>> | 92% | 56,173 psi | 88% | 3022 fps | 100% |
| Bofors RP7 | <<locked>> | 82% | 55,085 psi | 86% | 2897 fps | 100% |
| Hodgdon H1000 | <<locked>> | 98% | 55,753 psi | 87% | 3022 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 82% | 54,781 psi | 86% | 2953 fps | 100% |
| Hodgdon H4350 | <<locked>> | 82% | 57,188 psi | 90% | 2966 fps | 100% |
| Hodgdon H4831 | <<locked>> | 90% | 55,593 psi | 87% | 2966 fps | 99.1% |
| Hodgdon H4831 SC | <<locked>> | 90% | 54,578 psi | 86% | 2946 fps | 99% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 54,636 psi | 86% | 2877 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 56,260 psi | 88% | 3140 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 55,434 psi | 87% | 2992 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,275 psi | 58% | 1867 fps | 100% |
| IMR 4350 | <<locked>> | 86% | 57,174 psi | 90% | 2943 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 82% | 56,579 psi | 89% | 2923 fps | 100% |
| IMR 4831 | <<locked>> | 86% | 57,334 psi | 90% | 2943 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 56,304 psi | 88% | 2946 fps | 99.3% |
| IMR 7828 SSC | <<locked>> | 92% | 53,969 psi | 85% | 3009 fps | 99.4% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 43,787 psi | 69% | 2858 fps | 98.2% |
| Lovex S065 | <<locked>> | 84% | 57,334 psi | 90% | 2917 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 55,622 psi | 87% | 2917 fps | 100% |
| Lovex S071 | <<locked>> | 98% | 57,130 psi | 90% | 2940 fps | 100% |
| Norma 204 | <<locked>> | 84% | 54,534 psi | 85% | 2943 fps | 99.8% |
| Norma 217ᴾ | <<locked>> | 100% | 44,121 psi | 69% | 2881 fps | 99.7% |
| Norma MRP | <<locked>> | 90% | 56,144 psi | 88% | 3045 fps | 100% |
| Norma URP | <<locked>> | 84% | 55,332 psi | 87% | 2936 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 54,839 psi | 86% | 3028 fps | 99.7% |
| Ramshot Hunter | <<locked>> | 84% | 54,259 psi | 85% | 2943 fps | 100% |
| Ramshot Magnum | <<locked>> | 96% | 57,566 psi | 90% | 3022 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,101 psi | 60% | 1913 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 57,116 psi | 90% | 2976 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 84% | 55,724 psi | 87% | 3005 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 57,188 psi | 90% | 3130 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 56,507 psi | 89% | 3094 fps | 99.3% |
| Rottweil R 904 | <<locked>> | 88% | 55,201 psi | 87% | 2933 fps | 99.4% |
| Rottweil R 905 | <<locked>> | 90% | 57,014 psi | 89% | 2995 fps | 100% |
| Rottweil R 907 | <<locked>> | 82% | 55,085 psi | 86% | 2897 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 84% | 57,334 psi | 90% | 2917 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 55,622 psi | 87% | 2917 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 56,420 psi | 88% | 2871 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 56,594 psi | 89% | 2992 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 56,695 psi | 89% | 2923 fps | 99.2% |
| Somchem S365 | <<locked>> | 86% | 56,246 psi | 88% | 2936 fps | 100% |
| Somchem S385 | <<locked>> | 90% | 57,493 psi | 90% | 2966 fps | 100% |
| Vihtavuori N150 | <<locked>> | 82% | 57,377 psi | 90% | 2851 fps | 100% |
| Vihtavuori N160 | <<locked>> | 84% | 57,029 psi | 89% | 2923 fps | 100% |
| Vihtavuori N165 | <<locked>> | 94% | 57,217 psi | 90% | 2946 fps | 100% |
| Vihtavuori N170 | <<locked>> | 98% | 55,985 psi | 88% | 2959 fps | 96% |
| Vihtavuori N550 | <<locked>> | 84% | 56,159 psi | 88% | 2930 fps | 100% |
| Vihtavuori N555 | <<locked>> | 90% | 55,767 psi | 87% | 2959 fps | 100% |
| Vihtavuori N560 | <<locked>> | 90% | 55,825 psi | 87% | 3045 fps | 99.4% |
| Vihtavuori N565 | <<locked>> | 96% | 55,999 psi | 88% | 3025 fps | 99.5% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 57,130 psi | 90% | 3091 fps | 99% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 53,940 psi | 85% | 3084 fps | 97% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 56,565 psi | 89% | 2877 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 54,940 psi | 86% | 2956 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 94% | 56,565 psi | 89% | 3074 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 92% | 57,493 psi | 90% | 2966 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% | 36,956 psi | 58% | 2589 fps | 99% |
| Accurate 4350 | <<locked>> | 80% | 49,530 psi | 78% | 2841 fps | 100% |
| Accurate MAGPRO | 96.2 gr | 82% | 41,104 psi | 64% | 2769 fps | 95.8% |
| ADI AR 2209 | <<locked>> | 80% | 41,321 psi | 65% | 2726 fps | 98% |
| ADI AR 2213 | <<locked>> | 80% | 36,767 psi | 58% | 2654 fps | 95.4% |
| ADI AR 2217 | <<locked>> | 88% | 35,665 psi | 56% | 2625 fps | 95.3% |
| ADI AR 2225 | <<locked>> | 86% | 30,095 psi | 47% | 2523 fps | 96.1% |
| Alliant Reloder-16 | <<locked>> | 80% | 47,688 psi | 75% | 2851 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 41,336 psi | 65% | 2720 fps | 98.1% |
| Alliant Reloder-22 | <<locked>> | 80% | 37,057 psi | 58% | 2661 fps | 97% |
| Alliant Reloder-23 | <<locked>> | 80% | 35,723 psi | 56% | 2615 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 30,864 psi | 48% | 2536 fps | 98.1% |
| Alliant Reloder-26 | <<locked>> | 80% | 39,798 psi | 62% | 2769 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 98% | 47,094 psi | 74% | 2940 fps | 95.6% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 47,413 psi | 74% | 2815 fps | 95.7% |
| Bofors RP15 | <<locked>> | 80% | 34,447 psi | 54% | 2595 fps | 95.9% |
| Bofors RP30 | <<locked>> | 86% | 34,954 psi | 55% | 2638 fps | 95.4% |
| Bofors RP5 | <<locked>> | 80% | 37,057 psi | 58% | 2661 fps | 97% |
| Bofors RP7 | <<locked>> | 80% | 51,619 psi | 81% | 2841 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 84% | 33,968 psi | 53% | 2582 fps | 95.2% |
| Hodgdon H414 | <<locked>> | 80% | 51,300 psi | 80% | 2897 fps | 100% |
| Hodgdon H4350 | <<locked>> | 80% | 53,606 psi | 84% | 2910 fps | 99.8% |
| Hodgdon H4831 | <<locked>> | 80% | 39,305 psi | 62% | 2661 fps | 95.6% |
| Hodgdon H4831 SC | <<locked>> | 80% | 38,566 psi | 60% | 2644 fps | 95.4% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 44,759 psi | 70% | 2726 fps | 100% |
| Hodgdon Retumbo | 91 gr | 82% | 32,285 psi | 51% | 2621 fps | 95.8% |
| Hodgdon Superformance | <<locked>> | 80% | 51,358 psi | 80% | 2927 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,833 psi | 44% | 1670 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 47,123 psi | 74% | 2779 fps | 99.6% |
| IMR 4451 Enduron | <<locked>> | 80% | 53,098 psi | 83% | 2867 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 46,978 psi | 74% | 2785 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 40,872 psi | 64% | 2661 fps | 96.3% |
| IMR 7828 SSC | <<locked>> | 82% | 38,087 psi | 60% | 2697 fps | 96% |
| IMR 8133 Enduron | <<locked>> | 94% | 35,520 psi | 56% | 2671 fps | 95.5% |
| Lovex S065 | <<locked>> | 80% | 50,444 psi | 79% | 2815 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 48,863 psi | 77% | 2808 fps | 99.9% |
| Lovex S071 | <<locked>> | 80% | 31,662 psi | 50% | 2464 fps | 97.6% |
| Norma 204 | <<locked>> | 80% | 47,413 psi | 74% | 2822 fps | 99% |
| Norma 217 | <<locked>> | 90% | 31,053 psi | 49% | 2572 fps | 96% |
| Norma MRP | <<locked>> | 80% | 39,059 psi | 61% | 2733 fps | 98.7% |
| Norma URP | <<locked>> | 80% | 48,443 psi | 76% | 2828 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 34,954 psi | 55% | 2631 fps | 95.2% |
| Ramshot Hunter | <<locked>> | 80% | 47,311 psi | 74% | 2828 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 31,096 psi | 49% | 2510 fps | 95.6% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,500 psi | 45% | 1709 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 49,705 psi | 78% | 2864 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 48,066 psi | 75% | 2887 fps | 100% |
| ReloadSwiss RS 76 | 95 gr | 80% | 29,138 psi | 46% | 2520 fps | 95.3% |
| ReloadSwiss RS 80 | <<locked>> | 90% | 38,116 psi | 60% | 2743 fps | 95% |
| Rottweil R 904 | <<locked>> | 80% | 42,453 psi | 67% | 2703 fps | 97.3% |
| Rottweil R 905 | <<locked>> | 80% | 40,640 psi | 64% | 2707 fps | 98.1% |
| Rottweil R 907 | <<locked>> | 80% | 51,619 psi | 81% | 2841 fps | 99.9% |
| Shooters World Long Rifle | <<locked>> | 80% | 50,444 psi | 79% | 2815 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 48,863 psi | 77% | 2808 fps | 99.9% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 49,371 psi | 77% | 2762 fps | 99.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 40,306 psi | 63% | 2700 fps | 98% |
| Somchem S361 | <<locked>> | 80% | 43,236 psi | 68% | 2690 fps | 96.8% |
| Somchem S365 | <<locked>> | 80% | 45,716 psi | 72% | 2779 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 41,075 psi | 64% | 2684 fps | 98.8% |
| Vihtavuori N150 | <<locked>> | 80% | 53,766 psi | 84% | 2805 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 49,966 psi | 78% | 2822 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 35,708 psi | 56% | 2559 fps | 97.1% |
| Vihtavuori N170 | <<locked>> | 96% | 52,243 psi | 82% | 2897 fps | 95.1% |
| Vihtavuori N550 | <<locked>> | 80% | 49,197 psi | 77% | 2822 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 39,900 psi | 63% | 2690 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 39,102 psi | 61% | 2723 fps | 95.8% |
| Vihtavuori N565 | <<locked>> | 84% | 36,796 psi | 58% | 2654 fps | 95.3% |
| Vihtavuori N568 | <<locked>> | 92% | 42,641 psi | 67% | 2828 fps | 95.9% |
| Vihtavuori N570 | <<locked>> | 96% | 46,586 psi | 73% | 2946 fps | 95% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 49,240 psi | 77% | 2772 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 51,445 psi | 81% | 2900 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 32,358 psi | 51% | 2651 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 37,710 psi | 59% | 2612 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 | Barnes TAC-TX BT. Hodgdon Retumbo delivers the highest muzzle velocity at 3,140 fps; across all powders the maximum-charge window runs from 1,867 fps to 3,140 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, Accurate MAGPRO rank at the top here: for .338-378 Weath. Mag. with the .338 | 225gr | Barnes TAC-TX BT they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Alliant Reloder-50, IMR 7977 Enduron, Lovex D100 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.