Load Specifications
Load data in caliber .30-378 Weath. Mag. with .308 | 170gr | Lapua Naturalis bullet and 53 powders. The key underlying parameters are shown in the table above.
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>> | 88% | 56,405 psi | 88% | 3114 fps | 100% |
| Accurate High Country | <<locked>> | 84% | 54,621 psi | 86% | 3222 fps | 99.7% |
| Accurate MAGPRO | <<locked>> | 86% | 55,651 psi | 87% | 3228 fps | 99.2% |
| ADI AR 2209 | <<locked>> | 84% | 54,114 psi | 85% | 3153 fps | 99.9% |
| ADI AR 2213 | <<locked>> | 88% | 56,420 psi | 88% | 3228 fps | 99.8% |
| ADI AR 2217 | <<locked>> | 96% | 55,245 psi | 87% | 3202 fps | 99.9% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 55,898 psi | 88% | 3327 fps | 98.3% |
| ADI AR 2225 | <<locked>> | 98% | 54,157 psi | 85% | 3222 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 86% | 57,522 psi | 90% | 3205 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 88% | 56,724 psi | 89% | 3222 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 88% | 54,926 psi | 86% | 3127 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 92% | 55,317 psi | 87% | 3199 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 84% | 55,361 psi | 87% | 3212 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 98% | 57,508 psi | 90% | 3301 fps | 98.3% |
| Alliant Reloder-50ᴾ | <<locked>> | 100% | 52,779 psi | 83% | 3202 fps | 96.9% |
| Baschieri & Pellagri 109 | <<locked>> | 90% | 57,087 psi | 89% | 3186 fps | 98.3% |
| Bofors RP15 | <<locked>> | 90% | 56,086 psi | 88% | 3212 fps | 100% |
| Bofors RP30 | <<locked>> | 94% | 55,071 psi | 86% | 3215 fps | 99.8% |
| Bofors RP5 | <<locked>> | 88% | 56,724 psi | 89% | 3222 fps | 100% |
| Hodgdon H1000 | <<locked>> | 94% | 56,884 psi | 89% | 3228 fps | 100% |
| Hodgdon H4831 | <<locked>> | 86% | 55,419 psi | 87% | 3156 fps | 99.4% |
| Hodgdon H4831 SC | <<locked>> | 86% | 54,433 psi | 85% | 3140 fps | 99.3% |
| Hodgdon Hybrid 100V | <<locked>> | 82% | 54,288 psi | 85% | 3058 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 92% | 54,418 psi | 85% | 3291 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,550 psi | 59% | 2051 fps | 100% |
| IMR 4350 | <<locked>> | 82% | 56,318 psi | 88% | 3130 fps | 100% |
| IMR 4831 | <<locked>> | 82% | 56,913 psi | 89% | 3127 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 86% | 55,796 psi | 87% | 3133 fps | 99.5% |
| IMR 7828 SSC | <<locked>> | 88% | 54,810 psi | 86% | 3209 fps | 99.7% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 53,011 psi | 83% | 3196 fps | 99.7% |
| Lovex S071 | <<locked>> | 92% | 54,534 psi | 85% | 3087 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 54,085 psi | 85% | 3219 fps | 100% |
| Norma MRP | <<locked>> | 86% | 56,942 psi | 89% | 3238 fps | 100% |
| Ramshot Grand | <<locked>> | 88% | 56,101 psi | 88% | 3232 fps | 99.9% |
| Ramshot Magnum | <<locked>> | 90% | 54,563 psi | 86% | 3156 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,580 psi | 60% | 2100 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 92% | 55,274 psi | 87% | 3274 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 94% | 54,505 psi | 85% | 3232 fps | 99.2% |
| Rottweil R 904 | <<locked>> | 84% | 54,679 psi | 86% | 3120 fps | 99.6% |
| Rottweil R 905 | <<locked>> | 86% | 57,116 psi | 90% | 3192 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 86% | 56,724 psi | 89% | 3189 fps | 100% |
| Somchem S361 | <<locked>> | 84% | 56,072 psi | 88% | 3110 fps | 99.4% |
| Somchem S365 | <<locked>> | 82% | 56,362 psi | 88% | 3120 fps | 100% |
| Somchem S385 | <<locked>> | 86% | 57,421 psi | 90% | 3159 fps | 100% |
| Vihtavuori N165 | <<locked>> | 90% | 57,522 psi | 90% | 3143 fps | 100% |
| Vihtavuori N170 | <<locked>> | 94% | 56,710 psi | 89% | 3163 fps | 96.7% |
| Vihtavuori N555 | <<locked>> | 86% | 56,536 psi | 89% | 3153 fps | 100% |
| Vihtavuori N560 | <<locked>> | 86% | 56,376 psi | 88% | 3241 fps | 99.6% |
| Vihtavuori N565 | <<locked>> | 92% | 57,276 psi | 90% | 3232 fps | 99.7% |
| Vihtavuori N568 | <<locked>> | 94% | 55,129 psi | 86% | 3238 fps | 99% |
| Vihtavuori N570 | <<locked>> | 96% | 56,391 psi | 88% | 3307 fps | 97.8% |
| Winchester StaBALL HD | <<locked>> | 88% | 54,955 psi | 86% | 3215 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 88% | 57,464 psi | 90% | 3156 fps | 100% |
Start Load - Barrel Length: 26"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 80% | 42,757 psi | 67% | 2874 fps | 99.8% |
| Accurate High Country | <<locked>> | 80% | 47,355 psi | 74% | 3084 fps | 98.7% |
| Accurate MAGPRO | <<locked>> | 80% | 44,730 psi | 70% | 3015 fps | 97.1% |
| ADI AR 2209 | <<locked>> | 80% | 47,181 psi | 74% | 3022 fps | 99.3% |
| ADI AR 2213 | <<locked>> | 80% | 42,467 psi | 67% | 2959 fps | 97.6% |
| ADI AR 2217 | <<locked>> | 84% | 36,071 psi | 57% | 2799 fps | 95.9% |
| ADI AR 2218 | <<locked>> | 96% | 47,906 psi | 75% | 3159 fps | 96.2% |
| ADI AR 2225 | <<locked>> | 80% | 28,674 psi | 45% | 2621 fps | 95.4% |
| Alliant Reloder-19 | <<locked>> | 80% | 47,079 psi | 74% | 3018 fps | 99.3% |
| Alliant Reloder-22 | <<locked>> | 80% | 43,105 psi | 68% | 2963 fps | 98.7% |
| Alliant Reloder-23 | <<locked>> | 80% | 41,814 psi | 66% | 2900 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 36,071 psi | 57% | 2825 fps | 99.5% |
| Alliant Reloder-26 | <<locked>> | 80% | 47,587 psi | 75% | 3077 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 92% | 45,600 psi | 71% | 3071 fps | 95.4% |
| Alliant Reloder-50 | <<locked>> | 98% | 48,834 psi | 77% | 3127 fps | 95.9% |
| Baschieri & Pellagri 109 | <<locked>> | 82% | 43,932 psi | 69% | 2930 fps | 95.2% |
| Bofors RP15 | <<locked>> | 80% | 39,972 psi | 63% | 2890 fps | 97.9% |
| Bofors RP30 | <<locked>> | 82% | 35,984 psi | 56% | 2812 fps | 95.9% |
| Bofors RP5 | <<locked>> | 80% | 43,105 psi | 68% | 2963 fps | 98.7% |
| Hodgdon H1000 | <<locked>> | 80% | 34,185 psi | 54% | 2749 fps | 95.7% |
| Hodgdon H4831 | <<locked>> | 80% | 44,933 psi | 70% | 2959 fps | 97.6% |
| Hodgdon H4831 SC | <<locked>> | 80% | 44,237 psi | 69% | 2943 fps | 97.4% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 50,894 psi | 80% | 3005 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 80% | 35,230 psi | 55% | 2864 fps | 97.4% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,239 psi | 44% | 1841 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 52,808 psi | 83% | 3068 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 53,287 psi | 84% | 3071 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 45,977 psi | 72% | 2953 fps | 98% |
| IMR 7828 SSC | <<locked>> | 80% | 41,133 psi | 64% | 2936 fps | 97.2% |
| IMR 8133 Enduron | <<locked>> | 88% | 34,737 psi | 54% | 2792 fps | 95.2% |
| Lovex S071 | <<locked>> | 80% | 36,709 psi | 58% | 2740 fps | 99% |
| Norma 217 | <<locked>> | 84% | 30,240 psi | 47% | 2684 fps | 95.5% |
| Norma MRP | <<locked>> | 80% | 45,905 psi | 72% | 3041 fps | 99.8% |
| Ramshot Grand | <<locked>> | 80% | 41,220 psi | 65% | 2949 fps | 97.7% |
| Ramshot Magnum | <<locked>> | 80% | 36,941 psi | 58% | 2808 fps | 98% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,848 psi | 45% | 1880 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 34,534 psi | 54% | 2835 fps | 98.2% |
| ReloadSwiss RS 80 | <<locked>> | 86% | 39,885 psi | 63% | 2930 fps | 95.7% |
| Rottweil R 904 | <<locked>> | 80% | 47,906 psi | 75% | 2995 fps | 98.8% |
| Rottweil R 905 | <<locked>> | 80% | 46,586 psi | 73% | 3002 fps | 99.3% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 46,253 psi | 72% | 2999 fps | 99.3% |
| Somchem S361 | <<locked>> | 80% | 48,965 psi | 77% | 2982 fps | 98.5% |
| Somchem S365 | <<locked>> | 80% | 52,620 psi | 82% | 3064 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 47,021 psi | 74% | 2976 fps | 99.7% |
| Vihtavuori N165 | <<locked>> | 80% | 41,031 psi | 64% | 2844 fps | 98.7% |
| Vihtavuori N170 | <<locked>> | 92% | 52,953 psi | 83% | 3097 fps | 95.8% |
| Vihtavuori N555 | <<locked>> | 80% | 46,296 psi | 73% | 2982 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 45,585 psi | 71% | 3035 fps | 97.9% |
| Vihtavuori N565 | <<locked>> | 80% | 37,536 psi | 59% | 2825 fps | 95.6% |
| Vihtavuori N568 | <<locked>> | 86% | 40,944 psi | 64% | 2949 fps | 95.5% |
| Vihtavuori N570 | <<locked>> | 92% | 48,675 psi | 76% | 3156 fps | 95.9% |
| Winchester StaBALL HD | <<locked>> | 80% | 40,074 psi | 63% | 2956 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 43,308 psi | 68% | 2900 fps | 98.7% |
ᴾ possible press load - work up slowly to this load while watching for signs of excessive pressure.
This overview compares 60 powders for .30-378 Weath. Mag. loaded with the .308 | 170gr | Lapua Naturalis. ADI AR 2218 delivers the highest muzzle velocity at 3,327 fps; across all powders the maximum-charge window runs from 2,051 fps to 3,327 fps. Accurate 8700 gives the best case fill at 100 %, and 60 of the 60 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 59–90 %, leaving at least 10 % headroom. The 170.0 gr projectile in 0.308" calls for a 1:11.5 twist; slower twists will usually not stabilise this weight. Accurate 8700, ADI AR 2218, Alliant Reloder-50 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. As outliers, Accurate 8700, 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.