Load Specifications
Load data in caliber .338-378 Weath. Mag. with .338 | 200gr | Alaska Bullet Works Kodiak SP SPBC bullet and 71 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% | 56,217 psi | 88% | 3081 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 56,927 psi | 89% | 3114 fps | 100% |
| Accurate MAGPRO | <<locked>> | 90% | 54,955 psi | 86% | 3179 fps | 98.2% |
| ADI AR 2209 | <<locked>> | 88% | 54,070 psi | 85% | 3114 fps | 99.5% |
| ADI AR 2213 | <<locked>> | 92% | 55,738 psi | 87% | 3179 fps | 99.1% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 53,998 psi | 85% | 3140 fps | 99.2% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 48,530 psi | 76% | 3100 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 84% | 54,143 psi | 85% | 3114 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 90% | 57,319 psi | 90% | 3163 fps | 99.8% |
| Alliant Reloder-22 | <<locked>> | 92% | 56,028 psi | 88% | 3176 fps | 99.7% |
| Alliant Reloder-23 | <<locked>> | 94% | 57,508 psi | 90% | 3143 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 98% | 57,290 psi | 90% | 3212 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 88% | 54,201 psi | 85% | 3179 fps | 100% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 57,145 psi | 90% | 3133 fps | 97.1% |
| Bofors RP15 | <<locked>> | 94% | 55,216 psi | 87% | 3159 fps | 99.6% |
| Bofors RP30ᴾ | <<locked>> | 100% | 56,971 psi | 89% | 3212 fps | 99.6% |
| Bofors RP5 | <<locked>> | 92% | 56,028 psi | 88% | 3176 fps | 99.7% |
| Bofors RP7 | <<locked>> | 82% | 55,056 psi | 86% | 3054 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 98% | 55,564 psi | 87% | 3169 fps | 99.7% |
| Hodgdon H414 | <<locked>> | 82% | 54,766 psi | 86% | 3110 fps | 100% |
| Hodgdon H4350 | <<locked>> | 82% | 57,058 psi | 89% | 3123 fps | 99.8% |
| Hodgdon H4831 | <<locked>> | 90% | 55,564 psi | 87% | 3117 fps | 98.6% |
| Hodgdon H4831 SC | <<locked>> | 90% | 54,476 psi | 85% | 3097 fps | 98.4% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 54,549 psi | 85% | 3035 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 56,057 psi | 88% | 3291 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 55,332 psi | 87% | 3143 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,289 psi | 58% | 1995 fps | 100% |
| IMR 4350 | <<locked>> | 86% | 56,927 psi | 89% | 3097 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 82% | 56,347 psi | 88% | 3077 fps | 100% |
| IMR 4831 | <<locked>> | 86% | 57,261 psi | 90% | 3100 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 56,333 psi | 88% | 3097 fps | 98.8% |
| IMR 7828 SSC | <<locked>> | 92% | 53,780 psi | 84% | 3156 fps | 98.9% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 43,990 psi | 69% | 2999 fps | 97.4% |
| Lovex S065 | <<locked>> | 84% | 57,319 psi | 90% | 3077 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 55,535 psi | 87% | 3074 fps | 100% |
| Lovex S071 | <<locked>> | 98% | 57,537 psi | 90% | 3100 fps | 100% |
| Norma 204 | <<locked>> | 84% | 54,360 psi | 85% | 3097 fps | 99.4% |
| Norma 217ᴾ | <<locked>> | 100% | 44,396 psi | 70% | 3025 fps | 99.2% |
| Norma MRP | <<locked>> | 90% | 56,057 psi | 88% | 3199 fps | 100% |
| Norma URP | <<locked>> | 84% | 55,129 psi | 86% | 3091 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 54,650 psi | 86% | 3179 fps | 99.3% |
| Ramshot Hunter | <<locked>> | 84% | 54,128 psi | 85% | 3097 fps | 100% |
| Ramshot Magnum | <<locked>> | 96% | 57,493 psi | 90% | 3173 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,072 psi | 60% | 2041 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 57,087 psi | 89% | 3133 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 84% | 55,492 psi | 87% | 3163 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 57,159 psi | 90% | 3287 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 56,608 psi | 89% | 3238 fps | 98.8% |
| Rottweil R 904 | <<locked>> | 88% | 55,042 psi | 86% | 3081 fps | 99% |
| Rottweil R 905 | <<locked>> | 90% | 56,913 psi | 89% | 3150 fps | 99.8% |
| Rottweil R 907 | <<locked>> | 82% | 55,056 psi | 86% | 3054 fps | 99.9% |
| Shooters World Long Rifle | <<locked>> | 84% | 57,319 psi | 90% | 3077 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 55,535 psi | 87% | 3074 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 56,420 psi | 88% | 3028 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 56,492 psi | 89% | 3146 fps | 99.7% |
| Somchem S361 | <<locked>> | 88% | 56,681 psi | 89% | 3071 fps | 98.7% |
| Somchem S365 | <<locked>> | 86% | 56,072 psi | 88% | 3094 fps | 100% |
| Somchem S385 | <<locked>> | 90% | 57,479 psi | 90% | 3120 fps | 100% |
| Vihtavuori N150 | <<locked>> | 82% | 57,276 psi | 90% | 3012 fps | 100% |
| Vihtavuori N160 | <<locked>> | 84% | 56,855 psi | 89% | 3081 fps | 100% |
| Vihtavuori N165 | <<locked>> | 94% | 57,130 psi | 90% | 3100 fps | 99.9% |
| Vihtavuori N550 | <<locked>> | 84% | 56,072 psi | 88% | 3087 fps | 100% |
| Vihtavuori N555 | <<locked>> | 90% | 55,999 psi | 88% | 3120 fps | 100% |
| Vihtavuori N560 | <<locked>> | 90% | 55,709 psi | 87% | 3196 fps | 98.8% |
| Vihtavuori N565 | <<locked>> | 96% | 56,057 psi | 88% | 3176 fps | 99% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 57,203 psi | 90% | 3241 fps | 98.4% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 53,969 psi | 85% | 3228 fps | 96% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 56,536 psi | 89% | 3031 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 54,911 psi | 86% | 3114 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 94% | 56,376 psi | 88% | 3232 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 92% | 57,435 psi | 90% | 3117 fps | 99.8% |
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% | 37,304 psi | 58% | 2730 fps | 98.4% |
| Accurate 4350 | <<locked>> | 80% | 49,661 psi | 78% | 2995 fps | 100% |
| Accurate MAGPRO | <<locked>> | 84% | 44,280 psi | 69% | 2972 fps | 95.7% |
| ADI AR 2209 | <<locked>> | 80% | 41,249 psi | 65% | 2864 fps | 97.2% |
| ADI AR 2213 | <<locked>> | 82% | 39,494 psi | 62% | 2854 fps | 95.3% |
| ADI AR 2217 | <<locked>> | 90% | 38,392 psi | 60% | 2818 fps | 95.2% |
| ADI AR 2225 | <<locked>> | 88% | 32,532 psi | 51% | 2713 fps | 96.1% |
| Alliant Reloder-16 | <<locked>> | 80% | 47,471 psi | 74% | 3002 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 41,307 psi | 65% | 2858 fps | 97.2% |
| Alliant Reloder-22 | <<locked>> | 80% | 37,173 psi | 58% | 2799 fps | 96% |
| Alliant Reloder-23 | <<locked>> | 80% | 35,926 psi | 56% | 2759 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 31,082 psi | 49% | 2664 fps | 97.2% |
| Alliant Reloder-26 | <<locked>> | 80% | 39,842 psi | 62% | 2913 fps | 99.8% |
| Baschieri & Pellagri 109 | <<locked>> | 90% | 50,459 psi | 79% | 3015 fps | 95.6% |
| Bofors RP15 | <<locked>> | 82% | 37,028 psi | 58% | 2792 fps | 95.8% |
| Bofors RP30 | <<locked>> | 88% | 37,695 psi | 59% | 2835 fps | 95.4% |
| Bofors RP5 | <<locked>> | 80% | 37,173 psi | 58% | 2799 fps | 96% |
| Bofors RP7 | <<locked>> | 80% | 51,677 psi | 81% | 2999 fps | 99.6% |
| Hodgdon H1000 | <<locked>> | 86% | 36,550 psi | 57% | 2772 fps | 95.1% |
| Hodgdon H414 | <<locked>> | 80% | 51,198 psi | 80% | 3051 fps | 99.8% |
| Hodgdon H4350 | <<locked>> | 80% | 53,417 psi | 84% | 3064 fps | 99.5% |
| Hodgdon H4831 | <<locked>> | 82% | 42,134 psi | 66% | 2858 fps | 95.5% |
| Hodgdon H4831 SC | <<locked>> | 82% | 41,423 psi | 65% | 2841 fps | 95.3% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 44,759 psi | 70% | 2874 fps | 100% |
| Hodgdon Retumbo | 98.9 gr | 84% | 34,708 psi | 54% | 2815 fps | 95.6% |
| Hodgdon Superformance | <<locked>> | 80% | 51,343 psi | 80% | 3077 fps | 99.8% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,934 psi | 44% | 1788 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 47,036 psi | 74% | 2927 fps | 99.2% |
| IMR 4451 Enduron | <<locked>> | 80% | 52,968 psi | 83% | 3022 fps | 99.9% |
| IMR 4831 | <<locked>> | 80% | 47,007 psi | 74% | 2936 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 40,886 psi | 64% | 2799 fps | 95.3% |
| IMR 7828 SSC | <<locked>> | 84% | 40,770 psi | 64% | 2894 fps | 95.8% |
| IMR 8133 Enduron | <<locked>> | 96% | 38,348 psi | 60% | 2867 fps | 95.5% |
| Lovex S065 | <<locked>> | 80% | 50,575 psi | 79% | 2969 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 48,965 psi | 77% | 2959 fps | 99.7% |
| Lovex S071 | <<locked>> | 80% | 32,082 psi | 50% | 2598 fps | 96.8% |
| Norma 204 | <<locked>> | 80% | 47,442 psi | 74% | 2972 fps | 98.5% |
| Norma 217 | <<locked>> | 92% | 33,576 psi | 53% | 2766 fps | 95.9% |
| Norma MRP | <<locked>> | 80% | 39,175 psi | 61% | 2874 fps | 98% |
| Norma URP | <<locked>> | 80% | 48,428 psi | 76% | 2979 fps | 100% |
| Ramshot Grand | <<locked>> | 82% | 37,782 psi | 59% | 2831 fps | 95.1% |
| Ramshot Hunter | <<locked>> | 80% | 47,384 psi | 74% | 2979 fps | 99.8% |
| Ramshot Magnum | <<locked>> | 82% | 33,852 psi | 53% | 2703 fps | 95.7% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,587 psi | 45% | 1831 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 49,734 psi | 78% | 3015 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 47,906 psi | 75% | 3038 fps | 100% |
| ReloadSwiss RS 76 | 103.4 gr | 82% | 31,676 psi | 50% | 2717 fps | 95.4% |
| ReloadSwiss RS 80 | <<locked>> | 92% | 41,437 psi | 65% | 2949 fps | 95% |
| Rottweil R 904 | <<locked>> | 80% | 42,496 psi | 67% | 2841 fps | 96.4% |
| Rottweil R 905 | <<locked>> | 80% | 40,698 psi | 64% | 2844 fps | 97.2% |
| Rottweil R 907 | <<locked>> | 80% | 51,677 psi | 81% | 2999 fps | 99.6% |
| Shooters World Long Rifle | <<locked>> | 80% | 50,575 psi | 79% | 2969 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 48,965 psi | 77% | 2959 fps | 99.7% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 49,487 psi | 78% | 2913 fps | 99.7% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 40,364 psi | 63% | 2841 fps | 97.1% |
| Somchem S361 | <<locked>> | 80% | 43,323 psi | 68% | 2828 fps | 95.9% |
| Somchem S365 | <<locked>> | 80% | 45,701 psi | 72% | 2933 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 41,249 psi | 65% | 2825 fps | 98.1% |
| Vihtavuori N150 | <<locked>> | 80% | 53,722 psi | 84% | 2963 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 49,835 psi | 78% | 2972 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 35,810 psi | 56% | 2690 fps | 96.1% |
| Vihtavuori N550 | <<locked>> | 80% | 49,284 psi | 77% | 2976 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 40,205 psi | 63% | 2841 fps | 99.9% |
| Vihtavuori N560 | 100.2 gr | 82% | 42,047 psi | 66% | 2927 fps | 95.7% |
| Vihtavuori N565 | <<locked>> | 86% | 39,755 psi | 62% | 2854 fps | 95.2% |
| Vihtavuori N568 | <<locked>> | 94% | 45,963 psi | 72% | 3035 fps | 95.9% |
| Vihtavuori N570 | <<locked>> | 98% | 50,212 psi | 79% | 3159 fps | 95% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 49,226 psi | 77% | 2923 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 51,358 psi | 80% | 3054 fps | 99.8% |
| Winchester StaBALL HD | <<locked>> | 80% | 32,489 psi | 51% | 2789 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 37,840 psi | 59% | 2746 fps | 96.2% |
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 76 powders for .338-378 Weath. Mag. loaded with the .338 | 200gr | Alaska Bullet Works Kodiak SP SPBC. Hodgdon Retumbo delivers the highest muzzle velocity at 3,291 fps; across all powders the maximum-charge window runs from 1,995 fps to 3,291 fps. ADI AR 2217 gives the best case fill at 100 %, and 76 of the 76 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 200.0 gr projectile in 0.338" calls for a 1:16.0 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 | 200gr | Alaska Bullet Works Kodiak SP SPBC 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.