Load Specifications
Bullet:.375 | 225gr | Hornady SP
Bullet Manufacturer:Hornady
Bullet Weight:225 gr
Bullet Diameter:0.375"
Bullet Length:<<locked>>
Caliber:.378 Weath. Mag. load data
Case Length (l3):2.913"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:137 Grains of Water
Primer Size:Large Rifle Magnum (LRM)
Barrel Length:26"
Max. allowed Pressure:63,817 psi
Load data in caliber .378 Weath. Mag. with .375 | 225gr | Hornady SP bullet and 101 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ReloadSwiss RS 70, Alliant Reloder-16 and Alliant Reloder-26.
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.
A valid access license is required to use the Personalized Load Calculator.
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 2495 | <<locked>> | 84% | 56,811 psi | 89% | 3038 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 54,607 psi | 86% | 3051 fps | 98.2% |
| Accurate 3100ᴾ | <<locked>> | 100% | 52,083 psi | 82% | 3087 fps | 99.2% |
| Accurate 4064 | <<locked>> | 86% | 57,217 psi | 90% | 3097 fps | 100% |
| Accurate 4350 | <<locked>> | 92% | 54,143 psi | 85% | 3146 fps | 99.9% |
| Accurate High Countryᴾ | <<locked>> | 100% | 56,985 psi | 89% | 3301 fps | 97.3% |
| ADI AR 2206H | <<locked>> | 82% | 56,130 psi | 88% | 3127 fps | 100% |
| ADI AR 2208 | <<locked>> | 88% | 57,276 psi | 90% | 3130 fps | 100% |
| ADI AR 2209 | <<locked>> | 98% | 55,434 psi | 87% | 3189 fps | 97.7% |
| Alliant Power Pro 2000-MR | <<locked>> | 84% | 56,666 psi | 89% | 3264 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 98% | 55,463 psi | 87% | 3186 fps | 97.8% |
| Alliant Power Pro Varmint | <<locked>> | 98% | 55,463 psi | 87% | 3186 fps | 97.8% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 54,592 psi | 86% | 3100 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 84% | 54,781 psi | 86% | 3123 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 94% | 54,926 psi | 86% | 3212 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 90% | 56,333 psi | 88% | 3238 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 98% | 54,665 psi | 86% | 3176 fps | 97.7% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 51,706 psi | 81% | 3173 fps | 97.3% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 48,834 psi | 77% | 3110 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 42,685 psi | 67% | 3015 fps | 98.3% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 56,246 psi | 88% | 3317 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 82% | 56,159 psi | 88% | 3143 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 47,384 psi | 74% | 3087 fps | 96.1% |
| Bofors RP3 | <<locked>> | 86% | 55,434 psi | 87% | 3120 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 51,706 psi | 81% | 3173 fps | 97.3% |
| Bofors RP7 | <<locked>> | 90% | 54,882 psi | 86% | 3097 fps | 98.4% |
| Hodgdon H380 | <<locked>> | 86% | 55,927 psi | 88% | 3136 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 92% | 56,536 psi | 89% | 3205 fps | 99.1% |
| Hodgdon H4350 | <<locked>> | 90% | 56,405 psi | 88% | 3163 fps | 98.2% |
| Hodgdon H4831ᴾ | <<locked>> | 100% | 56,971 psi | 89% | 3182 fps | 96.1% |
| Hodgdon H4895 | <<locked>> | 82% | 56,753 psi | 89% | 3136 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 55,158 psi | 86% | 3127 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 84% | 57,072 psi | 89% | 3176 fps | 100% |
| Hodgdon Superformance | <<locked>> | 92% | 57,029 psi | 89% | 3245 fps | 99% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,201 psi | 57% | 1959 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 54,317 psi | 85% | 3084 fps | 100% |
| IMR 3031 | <<locked>> | 82% | 57,392 psi | 90% | 3114 fps | 100% |
| IMR 4064 | <<locked>> | 86% | 56,768 psi | 89% | 3114 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 84% | 56,101 psi | 88% | 3094 fps | 99% |
| IMR 4350 | <<locked>> | 94% | 55,840 psi | 88% | 3130 fps | 98.6% |
| IMR 4451 Enduron | <<locked>> | 90% | 56,594 psi | 89% | 3130 fps | 99% |
| IMR 4831 | <<locked>> | 94% | 54,621 psi | 86% | 3140 fps | 100% |
| IMR 4895 | <<locked>> | 84% | 56,231 psi | 88% | 3153 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 98% | 54,984 psi | 86% | 3110 fps | 95.9% |
| Lovex D073.6 | <<locked>> | 82% | 56,608 psi | 89% | 3097 fps | 100% |
| Lovex S060 | <<locked>> | 82% | 54,926 psi | 86% | 3045 fps | 100% |
| Lovex S062 | <<locked>> | 86% | 56,927 psi | 89% | 3107 fps | 100% |
| Lovex S065 | <<locked>> | 92% | 56,507 psi | 89% | 3120 fps | 99.7% |
| Lovex S070 | <<locked>> | 92% | 54,404 psi | 85% | 3107 fps | 98.9% |
| Lovex S071ᴾ | <<locked>> | 100% | 43,120 psi | 68% | 2923 fps | 97.6% |
| Norma 201 | <<locked>> | 82% | 54,795 psi | 86% | 3064 fps | 100% |
| Norma 202 | <<locked>> | 82% | 55,593 psi | 87% | 3064 fps | 100% |
| Norma 203B | <<locked>> | 86% | 57,638 psi | 90% | 3163 fps | 100% |
| Norma 204 | <<locked>> | 94% | 56,666 psi | 89% | 3186 fps | 97.8% |
| Norma MRPᴾ | <<locked>> | 100% | 55,013 psi | 86% | 3264 fps | 99% |
| Norma URP | <<locked>> | 94% | 56,579 psi | 89% | 3192 fps | 100% |
| Ramshot Big Game | <<locked>> | 84% | 54,781 psi | 86% | 3133 fps | 100% |
| Ramshot Hunter | <<locked>> | 94% | 55,419 psi | 87% | 3189 fps | 99.5% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 45,223 psi | 71% | 3018 fps | 96.3% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,883 psi | 58% | 2005 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 86% | 55,840 psi | 88% | 3117 fps | 99.3% |
| ReloadSwiss RS 52 | <<locked>> | 82% | 55,738 psi | 87% | 3196 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 88% | 55,840 psi | 88% | 3232 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 54,070 psi | 85% | 3169 fps | 99.9% |
| ReloadSwiss RS 70 | <<locked>> | 94% | 56,521 psi | 89% | 3261 fps | 100% |
| Rottweil R 902 | <<locked>> | 84% | 55,463 psi | 87% | 3064 fps | 100% |
| Rottweil R 903 | <<locked>> | 88% | 55,405 psi | 87% | 3110 fps | 100% |
| Rottweil R 904 | <<locked>> | 98% | 57,188 psi | 90% | 3159 fps | 96.9% |
| Rottweil R 905ᴾ | <<locked>> | 100% | 57,479 psi | 90% | 3219 fps | 98.3% |
| Rottweil R 907 | <<locked>> | 90% | 54,882 psi | 86% | 3097 fps | 98.4% |
| Shooters World Long Rifle | <<locked>> | 92% | 56,507 psi | 89% | 3120 fps | 99.7% |
| Shooters World Match Rifle | <<locked>> | 82% | 56,608 psi | 89% | 3097 fps | 100% |
| Shooters World Precision | <<locked>> | 86% | 56,927 psi | 89% | 3107 fps | 100% |
| Shooters World SW4350 | <<locked>> | 92% | 54,404 psi | 85% | 3107 fps | 98.9% |
| SNPE Vectan SP 11 | <<locked>> | 88% | 57,058 psi | 89% | 3176 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 82% | 57,508 psi | 90% | 3130 fps | 99.9% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 54,621 psi | 86% | 3094 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 82% | 55,753 psi | 87% | 2992 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 88% | 56,565 psi | 89% | 2992 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 92% | 56,463 psi | 88% | 3071 fps | 99% |
| SNPE Vectan Tubal 8000ᴾ | <<locked>> | 100% | 56,971 psi | 89% | 3215 fps | 98.2% |
| Somchem S335 | <<locked>> | 82% | 55,317 psi | 87% | 2989 fps | 100% |
| Somchem S341 | <<locked>> | 82% | 57,159 psi | 90% | 3114 fps | 100% |
| Somchem S355 | <<locked>> | 88% | 55,376 psi | 87% | 3107 fps | 100% |
| Somchem S365 | <<locked>> | 96% | 55,796 psi | 87% | 3192 fps | 100% |
| Somchem S385 | <<locked>> | 98% | 54,491 psi | 85% | 3133 fps | 98.4% |
| Vihtavuori N133 | <<locked>> | 82% | 56,260 psi | 88% | 2976 fps | 100% |
| Vihtavuori N135 | <<locked>> | 84% | 55,709 psi | 87% | 3022 fps | 100% |
| Vihtavuori N140 | <<locked>> | 84% | 56,202 psi | 88% | 3041 fps | 100% |
| Vihtavuori N150 | <<locked>> | 90% | 56,826 psi | 89% | 3081 fps | 100% |
| Vihtavuori N160 | <<locked>> | 92% | 55,100 psi | 86% | 3127 fps | 99.9% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 50,314 psi | 79% | 3045 fps | 97.3% |
| Vihtavuori N540 | <<locked>> | 84% | 54,346 psi | 85% | 3035 fps | 100% |
| Vihtavuori N550 | <<locked>> | 92% | 54,418 psi | 85% | 3133 fps | 99.9% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 54,592 psi | 86% | 3192 fps | 100% |
| Vihtavuori N560ᴾ | <<locked>> | 100% | 55,434 psi | 87% | 3251 fps | 96.2% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 54,897 psi | 86% | 3091 fps | 100% |
| Winchester 760 | <<locked>> | 92% | 56,681 psi | 89% | 3209 fps | 99.2% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 44,063 psi | 69% | 3159 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 82% | 54,665 psi | 86% | 3100 fps | 100% |
| Winchester Supreme 780ᴾ | <<locked>> | 100% | 54,679 psi | 86% | 3127 fps | 97.6% |
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 2495 | <<locked>> | 80% | 49,922 psi | 78% | 2940 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 47,863 psi | 75% | 2930 fps | 96.9% |
| Accurate 3100 | <<locked>> | 90% | 36,854 psi | 58% | 2785 fps | 95.8% |
| Accurate 4064 | <<locked>> | 80% | 47,253 psi | 74% | 2943 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 35,766 psi | 56% | 2779 fps | 97.2% |
| Accurate High Country | <<locked>> | 96% | 49,443 psi | 77% | 3163 fps | 95.6% |
| ADI AR 2206H | <<locked>> | 80% | 52,692 psi | 83% | 3071 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 44,744 psi | 70% | 2910 fps | 99.4% |
| ADI AR 2209 | <<locked>> | 92% | 45,498 psi | 71% | 3002 fps | 95.3% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 49,168 psi | 77% | 3133 fps | 99.9% |
| Alliant Power Pro Varmint | <<locked>> | 92% | 45,440 psi | 71% | 2999 fps | 95.4% |
| Alliant Power Pro Varmint | <<locked>> | 92% | 45,440 psi | 71% | 2999 fps | 95.4% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 45,136 psi | 71% | 2936 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 48,254 psi | 76% | 3009 fps | 99.8% |
| Alliant Reloder-16 | 90 gr | 80% | 35,085 psi | 55% | 2792 fps | 97.2% |
| Alliant Reloder-17 | <<locked>> | 80% | 39,639 psi | 62% | 2927 fps | 99.6% |
| Alliant Reloder-19 | <<locked>> | 92% | 44,933 psi | 70% | 2992 fps | 95.4% |
| Alliant Reloder-22 | <<locked>> | 96% | 45,295 psi | 71% | 3045 fps | 95.7% |
| Alliant Reloder-23 | <<locked>> | 82% | 27,311 psi | 43% | 2575 fps | 95.3% |
| Alliant Reloder-25 | <<locked>> | 94% | 35,244 psi | 55% | 2825 fps | 95.7% |
| Alliant Reloder-26 | 106.8 gr | 86% | 33,707 psi | 53% | 2831 fps | 96% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 52,504 psi | 82% | 3084 fps | 99.9% |
| Bofors RP15 | <<locked>> | 98% | 44,425 psi | 70% | 3025 fps | 95.2% |
| Bofors RP3 | <<locked>> | 80% | 45,368 psi | 71% | 2946 fps | 100% |
| Bofors RP5 | <<locked>> | 96% | 45,295 psi | 71% | 3045 fps | 95.7% |
| Bofors RP7 | <<locked>> | 80% | 40,059 psi | 63% | 2802 fps | 95% |
| Hodgdon H380 | <<locked>> | 80% | 45,803 psi | 72% | 2953 fps | 99% |
| Hodgdon H414 | <<locked>> | 82% | 40,480 psi | 63% | 2890 fps | 95.8% |
| Hodgdon H4350 | <<locked>> | 82% | 43,482 psi | 68% | 2917 fps | 95.2% |
| Hodgdon H4831 | <<locked>> | 98% | 53,156 psi | 83% | 3117 fps | 95.2% |
| Hodgdon H4895 | <<locked>> | 80% | 53,287 psi | 84% | 3081 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 32,576 psi | 51% | 2677 fps | 97.9% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 49,864 psi | 78% | 3058 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 39,610 psi | 62% | 2900 fps | 95% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,992 psi | 42% | 1752 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 50,937 psi | 80% | 3028 fps | 100% |
| IMR 3031 | <<locked>> | 80% | 53,824 psi | 84% | 3061 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 47,065 psi | 74% | 2946 fps | 99.7% |
| IMR 4166 Enduron | <<locked>> | 80% | 49,371 psi | 77% | 2976 fps | 97.9% |
| IMR 4350 | <<locked>> | 84% | 40,698 psi | 64% | 2838 fps | 95.2% |
| IMR 4451 Enduron | <<locked>> | 80% | 41,495 psi | 65% | 2838 fps | 96% |
| IMR 4831 | <<locked>> | 80% | 34,476 psi | 54% | 2730 fps | 96.8% |
| IMR 4895 | <<locked>> | 80% | 49,472 psi | 78% | 3041 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 51,634 psi | 81% | 3051 fps | 95.1% |
| Lovex D073.6 | <<locked>> | 80% | 52,953 psi | 83% | 3045 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 51,735 psi | 81% | 2992 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 47,268 psi | 74% | 2946 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 39,001 psi | 61% | 2782 fps | 96.8% |
| Lovex S070 | <<locked>> | 82% | 39,740 psi | 62% | 2818 fps | 95.8% |
| Lovex S071 | <<locked>> | 94% | 35,563 psi | 56% | 2753 fps | 95.3% |
| Norma 201 | <<locked>> | 80% | 51,547 psi | 81% | 3012 fps | 100% |
| Norma 202 | <<locked>> | 80% | 52,127 psi | 82% | 3012 fps | 100% |
| Norma 203B | <<locked>> | 80% | 47,601 psi | 75% | 2995 fps | 99.9% |
| Norma 204 | <<locked>> | 88% | 46,079 psi | 72% | 2992 fps | 95.4% |
| Norma MRP | <<locked>> | 90% | 38,870 psi | 61% | 2930 fps | 95.1% |
| Norma URP | <<locked>> | 80% | 35,708 psi | 56% | 2776 fps | 97% |
| Ramshot Big Game | <<locked>> | 80% | 47,819 psi | 75% | 3015 fps | 99.9% |
| Ramshot Hunter | <<locked>> | 82% | 37,057 psi | 58% | 2818 fps | 95.7% |
| Ramshot Magnum | <<locked>> | 98% | 41,989 psi | 66% | 2946 fps | 95.3% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,456 psi | 43% | 1795 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 45,876 psi | 72% | 2933 fps | 97.8% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 51,982 psi | 81% | 3133 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 42,105 psi | 66% | 2992 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 35,476 psi | 56% | 2795 fps | 96.7% |
| ReloadSwiss RS 70 | 98.4 gr | 80% | 34,693 psi | 54% | 2795 fps | 95.8% |
| Rottweil R 902 | <<locked>> | 80% | 49,110 psi | 77% | 2959 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 42,685 psi | 67% | 2887 fps | 99.8% |
| Rottweil R 904 | <<locked>> | 94% | 50,212 psi | 79% | 3035 fps | 95.4% |
| Rottweil R 905 | <<locked>> | 92% | 43,932 psi | 69% | 2969 fps | 95.3% |
| Rottweil R 907 | <<locked>> | 80% | 40,059 psi | 63% | 2802 fps | 95% |
| Shooters World Long Rifle | <<locked>> | 80% | 39,001 psi | 61% | 2782 fps | 96.8% |
| Shooters World Match Rifle | <<locked>> | 80% | 52,953 psi | 83% | 3045 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 47,268 psi | 74% | 2946 fps | 100% |
| Shooters World SW4350 | <<locked>> | 82% | 39,740 psi | 62% | 2818 fps | 95.8% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 43,772 psi | 69% | 2943 fps | 99.6% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 53,679 psi | 84% | 3071 fps | 99.7% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 51,198 psi | 80% | 3038 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 52,417 psi | 82% | 2946 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 44,193 psi | 69% | 2799 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 38,203 psi | 60% | 2720 fps | 95.1% |
| SNPE Vectan Tubal 8000 | <<locked>> | 92% | 43,511 psi | 68% | 2966 fps | 95.1% |
| Somchem S335 | <<locked>> | 80% | 52,127 psi | 82% | 2940 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 53,388 psi | 84% | 3054 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 43,105 psi | 68% | 2887 fps | 99.7% |
| Somchem S365 | <<locked>> | 80% | 32,169 psi | 50% | 2726 fps | 99% |
| Somchem S385 | <<locked>> | 90% | 41,887 psi | 66% | 2894 fps | 95.6% |
| Vihtavuori N133 | <<locked>> | 80% | 52,910 psi | 83% | 2927 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 49,226 psi | 77% | 2927 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 49,472 psi | 78% | 2940 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 41,118 psi | 64% | 2815 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 37,072 psi | 58% | 2776 fps | 97.4% |
| Vihtavuori N165 | <<locked>> | 96% | 44,019 psi | 69% | 2927 fps | 95.8% |
| Vihtavuori N540 | <<locked>> | 80% | 47,819 psi | 75% | 2930 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 36,593 psi | 57% | 2776 fps | 97% |
| Vihtavuori N555 | <<locked>> | 82% | 29,907 psi | 47% | 2661 fps | 95.5% |
| Vihtavuori N560 | <<locked>> | 98% | 51,779 psi | 81% | 3182 fps | 95.3% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 36,361 psi | 57% | 2746 fps | 99.1% |
| Winchester 760 | <<locked>> | 82% | 40,582 psi | 64% | 2894 fps | 95.9% |
| Winchester StaBALL HD | <<locked>> | 86% | 27,572 psi | 43% | 2671 fps | 96.3% |
| Winchester StaBALL Match | <<locked>> | 80% | 51,140 psi | 80% | 3045 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 94% | 44,280 psi | 69% | 2936 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 101 powders for .378 Weath. Mag. loaded with the .375 | 225gr | Hornady SP. Alliant Reloder-26 delivers the highest muzzle velocity at 3,317 fps; across all powders the maximum-charge window runs from 1,959 fps to 3,317 fps. Accurate 3100 gives the best case fill at 100 %, and 101 of the 101 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 57–90 %, leaving at least 10 % headroom. Accurate 3100, Accurate High Country, Alliant Reloder-22 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. ReloadSwiss RS 70, Alliant Reloder-16, Alliant Reloder-26 rank at the top here: for .378 Weath. Mag. with the .375 | 225gr | Hornady SP 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.