Load Specifications
Load data in caliber .338-378 Weath. Mag. with .338 | 172gr | Sax KDG-S bullet and 76 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-26, SNPE Vectan Tubal 8000 and Bofors RP5.
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 2700 | <<locked>> | 84% | 56,159 psi | 88% | 3202 fps | 99.2% |
| Accurate 3100 | <<locked>> | 94% | 54,302 psi | 85% | 3163 fps | 99.6% |
| Accurate 4350 | <<locked>> | 86% | 55,347 psi | 87% | 3278 fps | 100% |
| ADI AR 2208 | <<locked>> | 82% | 55,825 psi | 87% | 3172 fps | 100% |
| ADI AR 2209 | <<locked>> | 92% | 55,666 psi | 87% | 3249 fps | 98.1% |
| ADI AR 2213 | <<locked>> | 96% | 57,116 psi | 90% | 3305 fps | 97.4% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 43,801 psi | 69% | 3070 fps | 97.4% |
| Alliant Reloder- TS 15.5 | <<locked>> | 82% | 57,522 psi | 90% | 3204 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 88% | 55,405 psi | 87% | 3266 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 84% | 56,768 psi | 89% | 3285 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 92% | 55,201 psi | 87% | 3236 fps | 98.1% |
| Alliant Reloder-22 | <<locked>> | 96% | 57,145 psi | 90% | 3307 fps | 98.6% |
| Alliant Reloder-23 | <<locked>> | 96% | 54,578 psi | 86% | 3232 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 54,766 psi | 86% | 3282 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 92% | 55,085 psi | 86% | 3318 fps | 100% |
| Bofors RP15 | <<locked>> | 98% | 56,159 psi | 88% | 3356 fps | 98.8% |
| Bofors RP30ᴾ | <<locked>> | 100% | 51,111 psi | 80% | 3199 fps | 96.6% |
| Bofors RP5 | <<locked>> | 96% | 57,145 psi | 90% | 3376 fps | 99% |
| Bofors RP7 | <<locked>> | 86% | 57,566 psi | 90% | 3206 fps | 99.1% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 47,297 psi | 74% | 3182 fps | 96.8% |
| Hodgdon H414 | <<locked>> | 84% | 57,638 psi | 90% | 3274 fps | 99.4% |
| Hodgdon H4350 | <<locked>> | 88% | 55,622 psi | 87% | 3284 fps | 98.8% |
| Hodgdon H4831 | <<locked>> | 98% | 56,753 psi | 89% | 3229 fps | 96.5% |
| Hodgdon H4831 SC | <<locked>> | 94% | 56,115 psi | 88% | 3224 fps | 96.5% |
| Hodgdon Hybrid 100V | <<locked>> | 90% | 55,999 psi | 88% | 3187 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 50,415 psi | 79% | 3369 fps | 98.9% |
| Hodgdon Superformance | <<locked>> | 86% | 57,159 psi | 90% | 3291 fps | 99.3% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 38,029 psi | 60% | 2084 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 56,913 psi | 89% | 3258 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 54,998 psi | 86% | 3212 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 84% | 56,840 psi | 89% | 3180 fps | 99.3% |
| IMR 4350 | <<locked>> | 88% | 55,317 psi | 87% | 3248 fps | 99.2% |
| IMR 4451 Enduron | <<locked>> | 86% | 56,797 psi | 89% | 3271 fps | 99.6% |
| IMR 4831 | <<locked>> | 92% | 56,710 psi | 89% | 3220 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 94% | 56,173 psi | 88% | 3268 fps | 97.3% |
| IMR 7828 SSC | <<locked>> | 94% | 55,172 psi | 86% | 3282 fps | 97.1% |
| Lovex S065 | <<locked>> | 86% | 56,217 psi | 88% | 3178 fps | 99.8% |
| Lovex S070 | <<locked>> | 86% | 54,505 psi | 85% | 3168 fps | 99.2% |
| Lovex S071ᴾ | <<locked>> | 100% | 55,970 psi | 88% | 3178 fps | 99.6% |
| Norma 204 | <<locked>> | 88% | 56,304 psi | 88% | 3234 fps | 98.1% |
| Norma MRP | <<locked>> | 94% | 57,072 psi | 89% | 3334 fps | 99.4% |
| Norma URP | <<locked>> | 88% | 57,014 psi | 89% | 3247 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 55,027 psi | 86% | 3287 fps | 97.4% |
| Ramshot Hunter | <<locked>> | 88% | 55,840 psi | 88% | 3243 fps | 99.7% |
| Ramshot Magnum | <<locked>> | 96% | 56,434 psi | 88% | 3266 fps | 99.1% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,957 psi | 61% | 2134 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 82% | 56,043 psi | 88% | 3274 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 86% | 55,172 psi | 86% | 3228 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 88% | 56,927 psi | 89% | 3312 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 54,027 psi | 85% | 3334 fps | 99.6% |
| Rottweil R 903 | <<locked>> | 82% | 55,593 psi | 87% | 3168 fps | 100% |
| Rottweil R 904 | <<locked>> | 92% | 56,840 psi | 89% | 3215 fps | 97.4% |
| Rottweil R 905 | <<locked>> | 92% | 54,737 psi | 86% | 3224 fps | 98.1% |
| Rottweil R 907 | <<locked>> | 86% | 57,566 psi | 90% | 3206 fps | 99.1% |
| Shooters World Long Rifle | <<locked>> | 86% | 56,217 psi | 88% | 3178 fps | 99.8% |
| Shooters World SW4350 | <<locked>> | 88% | 55,521 psi | 87% | 3258 fps | 99.6% |
| SNPE Vectan SP 11 | <<locked>> | 82% | 56,565 psi | 89% | 3220 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 82% | 55,042 psi | 86% | 3034 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 55,521 psi | 87% | 3121 fps | 99.2% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 55,637 psi | 87% | 3320 fps | 98.8% |
| Somchem S355 | <<locked>> | 82% | 55,172 psi | 86% | 3161 fps | 100% |
| Somchem S361 | <<locked>> | 90% | 55,201 psi | 87% | 3141 fps | 96.3% |
| Somchem S365 | <<locked>> | 90% | 57,406 psi | 90% | 3251 fps | 100% |
| Somchem S385 | <<locked>> | 92% | 55,666 psi | 87% | 3202 fps | 98.9% |
| Unknown powder | <<locked>> | 86% | 57,145 psi | 90% | 3250 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 56,811 psi | 89% | 3142 fps | 100% |
| Vihtavuori N160 | <<locked>> | 86% | 57,566 psi | 90% | 3213 fps | 100% |
| Vihtavuori N165 | <<locked>> | 98% | 56,594 psi | 89% | 3199 fps | 98.8% |
| Vihtavuori N550 | <<locked>> | 84% | 54,665 psi | 86% | 3207 fps | 100% |
| Vihtavuori N555 | <<locked>> | 94% | 57,188 psi | 90% | 3268 fps | 100% |
| Vihtavuori N560 | <<locked>> | 96% | 57,377 psi | 90% | 3330 fps | 97% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 57,174 psi | 90% | 3295 fps | 97.3% |
| Winchester 6.5 StaBALL | <<locked>> | 86% | 54,694 psi | 86% | 3133 fps | 100% |
| Winchester 760 | <<locked>> | 84% | 57,638 psi | 90% | 3274 fps | 99.4% |
| Winchester StaBALL HD | <<locked>> | 98% | 56,260 psi | 88% | 3371 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 92% | 57,014 psi | 89% | 3215 fps | 98.4% |
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 2700 | <<locked>> | 80% | 49,211 psi | 77% | 3077 fps | 98.2% |
| Accurate 3100 | <<locked>> | 82% | 36,637 psi | 57% | 2804 fps | 95.9% |
| Accurate 4350 | <<locked>> | 80% | 45,324 psi | 71% | 3094 fps | 99.6% |
| ADI AR 2208 | <<locked>> | 80% | 52,562 psi | 82% | 3117 fps | 100% |
| ADI AR 2209 | <<locked>> | 86% | 45,730 psi | 72% | 3058 fps | 95.8% |
| ADI AR 2213 | <<locked>> | 92% | 50,096 psi | 79% | 3174 fps | 95.7% |
| ADI AR 2225 | <<locked>> | 96% | 38,174 psi | 60% | 2935 fps | 95.3% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 53,969 psi | 85% | 3148 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 42,757 psi | 67% | 3024 fps | 99.3% |
| Alliant Reloder-17 | <<locked>> | 80% | 49,313 psi | 77% | 3161 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 84% | 42,743 psi | 67% | 2984 fps | 95% |
| Alliant Reloder-22 | <<locked>> | 88% | 43,947 psi | 69% | 3051 fps | 95.5% |
| Alliant Reloder-23 | <<locked>> | 80% | 32,460 psi | 51% | 2766 fps | 97.9% |
| Alliant Reloder-25 | <<locked>> | 86% | 34,505 psi | 54% | 2837 fps | 95.6% |
| Alliant Reloder-26 | 97.6 gr | 80% | 35,462 psi | 56% | 2903 fps | 96.9% |
| Bofors RP15 | <<locked>> | 88% | 40,698 psi | 64% | 3045 fps | 95.1% |
| Bofors RP30 | <<locked>> | 98% | 46,847 psi | 73% | 3133 fps | 95.6% |
| Bofors RP5 | 98.7 gr | 86% | 41,133 psi | 64% | 3058 fps | 95.5% |
| Bofors RP7 | <<locked>> | 80% | 47,805 psi | 75% | 3027 fps | 97.5% |
| Hodgdon H1000 | <<locked>> | 98% | 44,135 psi | 69% | 3110 fps | 95.7% |
| Hodgdon H414 | <<locked>> | 80% | 50,401 psi | 79% | 3145 fps | 98.5% |
| Hodgdon H4350 | <<locked>> | 80% | 43,076 psi | 68% | 3038 fps | 96.2% |
| Hodgdon H4831 | <<locked>> | 96% | 52,939 psi | 83% | 3168 fps | 95.8% |
| Hodgdon H4831 SC | <<locked>> | 92% | 52,475 psi | 82% | 3159 fps | 95.6% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 40,553 psi | 64% | 2906 fps | 99.6% |
| Hodgdon Retumbo | <<locked>> | 94% | 41,234 psi | 65% | 3153 fps | 96.2% |
| Hodgdon Superformance | <<locked>> | 80% | 45,992 psi | 72% | 3082 fps | 97.3% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,789 psi | 44% | 1870 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 53,417 psi | 84% | 3202 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 51,851 psi | 81% | 3159 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 50,517 psi | 79% | 3067 fps | 98.5% |
| IMR 4350 | <<locked>> | 80% | 43,221 psi | 68% | 3009 fps | 97% |
| IMR 4451 Enduron | <<locked>> | 80% | 47,079 psi | 74% | 3091 fps | 98.3% |
| IMR 4831 | <<locked>> | 80% | 39,204 psi | 61% | 2880 fps | 98.3% |
| IMR 4955 Enduron | <<locked>> | 90% | 49,458 psi | 78% | 3143 fps | 95.8% |
| IMR 7828 SSC | <<locked>> | 90% | 48,109 psi | 75% | 3143 fps | 95.2% |
| Lovex S065 | <<locked>> | 80% | 46,833 psi | 73% | 3007 fps | 98.8% |
| Lovex S070 | <<locked>> | 80% | 45,223 psi | 71% | 2988 fps | 97.6% |
| Lovex S071 | <<locked>> | 86% | 35,781 psi | 56% | 2781 fps | 95.5% |
| Norma 204 | <<locked>> | 82% | 46,137 psi | 72% | 3042 fps | 95.8% |
| Norma MRP | <<locked>> | 84% | 40,364 psi | 63% | 2995 fps | 95.8% |
| Norma URP | <<locked>> | 80% | 44,164 psi | 69% | 3009 fps | 99.1% |
| Ramshot Grand | <<locked>> | 88% | 47,485 psi | 74% | 3139 fps | 95.4% |
| Ramshot Hunter | <<locked>> | 80% | 43,062 psi | 67% | 2996 fps | 97.7% |
| Ramshot Magnum | <<locked>> | 88% | 41,785 psi | 65% | 2983 fps | 95.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,413 psi | 45% | 1915 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 52,156 psi | 82% | 3214 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 44,933 psi | 70% | 3039 fps | 99.1% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 43,004 psi | 67% | 3046 fps | 98.7% |
| ReloadSwiss RS 76 | <<locked>> | 92% | 40,625 psi | 64% | 3037 fps | 96.3% |
| Rottweil R 903 | <<locked>> | 80% | 52,083 psi | 82% | 3110 fps | 100% |
| Rottweil R 904 | <<locked>> | 86% | 47,123 psi | 74% | 3032 fps | 95% |
| Rottweil R 905 | <<locked>> | 84% | 42,177 psi | 66% | 2972 fps | 95% |
| Rottweil R 907 | <<locked>> | 80% | 47,805 psi | 75% | 3027 fps | 97.5% |
| Shooters World Long Rifle | <<locked>> | 80% | 46,833 psi | 73% | 3007 fps | 98.8% |
| Shooters World SW4350 | <<locked>> | 80% | 42,946 psi | 67% | 3015 fps | 97.6% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 53,040 psi | 83% | 3162 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 51,866 psi | 81% | 2987 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 45,963 psi | 72% | 2946 fps | 97.7% |
| SNPE Vectan Tubal 8000 | 96.9 gr | 86% | 42,438 psi | 67% | 3061 fps | 95.9% |
| Somchem S355 | <<locked>> | 80% | 51,750 psi | 81% | 3103 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 51,764 psi | 81% | 3080 fps | 95.5% |
| Somchem S365 | <<locked>> | 80% | 41,060 psi | 64% | 2967 fps | 100% |
| Somchem S385 | <<locked>> | 82% | 40,350 psi | 63% | 2896 fps | 95.3% |
| Unknown powder | <<locked>> | 80% | 47,094 psi | 74% | 3069 fps | 99.2% |
| Vihtavuori N150 | <<locked>> | 80% | 44,672 psi | 70% | 2936 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 47,355 psi | 74% | 3038 fps | 99.5% |
| Vihtavuori N165 | <<locked>> | 88% | 41,104 psi | 64% | 2901 fps | 95.2% |
| Vihtavuori N550 | <<locked>> | 80% | 48,138 psi | 75% | 3089 fps | 99.5% |
| Vihtavuori N555 | <<locked>> | 80% | 36,448 psi | 57% | 2855 fps | 98% |
| Vihtavuori N560 | <<locked>> | 92% | 50,227 psi | 79% | 3197 fps | 95.3% |
| Vihtavuori N565 | <<locked>> | 96% | 49,879 psi | 78% | 3162 fps | 95.5% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 44,585 psi | 70% | 2961 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 50,401 psi | 79% | 3145 fps | 98.5% |
| Winchester StaBALL HD | <<locked>> | 80% | 29,240 psi | 46% | 2760 fps | 97.7% |
| Winchester Supreme 780 | <<locked>> | 84% | 43,004 psi | 67% | 2951 fps | 95.1% |
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 76 powders for .338-378 Weath. Mag. loaded with the .338 | 172gr | Sax KDG-S. Bofors RP5 delivers the highest muzzle velocity at 3,376 fps; across all powders the maximum-charge window runs from 2,084 fps to 3,376 fps. ADI AR 2225 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 60–90 %, leaving at least 10 % headroom. The 172.0 gr projectile in 0.338" calls for a 1:14.5 twist; slower twists will usually not stabilise this weight. ADI AR 2225, Alliant Reloder-25, Bofors RP30 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. Alliant Reloder-26, SNPE Vectan Tubal 8000, Bofors RP5 rank at the top here: for .338-378 Weath. Mag. with the .338 | 172gr | Sax KDG-S 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.