Load Specifications
Bullet:.338 | 254gr | CutEdge MTAC
Bullet Manufacturer:Cutting Edge
Bullet Weight:254 gr
Bullet Diameter:0.338"
Bullet Length:<<locked>>
Caliber:.338-378 Weath. Mag. load data
Case Length (l3):2.91"
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
Recommended Twist Rate:1:10.5
Load data in caliber .338-378 Weath. Mag. with .338 | 254gr | CutEdge MTAC bullet and 138 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 N570.
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 3100 | <<locked>> | 90% | 55,738 psi | 87% | 2762 fps | 100% |
| Accurate 3100 | <<locked>> | 90% | 56,115 psi | 88% | 2769 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 56,434 psi | 88% | 2779 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 56,869 psi | 89% | 2785 fps | 100% |
| Accurate High Country | <<locked>> | 88% | 57,711 psi | 90% | 2923 fps | 100% |
| Accurate High Country | <<locked>> | 86% | 54,230 psi | 85% | 2871 fps | 99.9% |
| Accurate MAGPRO | <<locked>> | 88% | 54,781 psi | 86% | 2871 fps | 99.5% |
| Accurate MAGPRO | <<locked>> | 88% | 55,143 psi | 86% | 2881 fps | 99.6% |
| ADI AR 2209 | <<locked>> | 88% | 57,595 psi | 90% | 2851 fps | 100% |
| ADI AR 2209 | <<locked>> | 86% | 54,288 psi | 85% | 2805 fps | 100% |
| ADI AR 2213 | <<locked>> | 90% | 55,738 psi | 87% | 2867 fps | 99.9% |
| ADI AR 2213 | <<locked>> | 90% | 56,115 psi | 88% | 2874 fps | 99.9% |
| ADI AR 2217 | <<locked>> | 98% | 53,940 psi | 85% | 2841 fps | 100% |
| ADI AR 2217 | <<locked>> | 98% | 54,288 psi | 85% | 2844 fps | 100% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 50,067 psi | 78% | 2881 fps | 97.7% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 50,604 psi | 79% | 2890 fps | 97.8% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 52,243 psi | 82% | 2861 fps | 100% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 52,547 psi | 82% | 2867 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 88% | 57,725 psi | 90% | 2848 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 86% | 54,505 psi | 85% | 2802 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 82% | 54,157 psi | 85% | 2782 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 82% | 54,621 psi | 86% | 2792 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 57,029 psi | 89% | 2841 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 57,406 psi | 90% | 2848 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 90% | 55,970 psi | 88% | 2861 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 90% | 56,333 psi | 88% | 2867 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 92% | 57,696 psi | 90% | 2815 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 90% | 54,418 psi | 85% | 2776 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 96% | 57,580 psi | 90% | 2887 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 94% | 54,215 psi | 85% | 2844 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 86% | 54,215 psi | 85% | 2854 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 86% | 54,665 psi | 86% | 2861 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 54,998 psi | 86% | 2933 fps | 98.6% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 55,680 psi | 87% | 2943 fps | 98.7% |
| Alliant Reloder-50ᴾ | <<locked>> | 100% | 46,224 psi | 72% | 2779 fps | 96.2% |
| Alliant Reloder-50ᴾ | <<locked>> | 100% | 46,644 psi | 73% | 2789 fps | 96.4% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 56,637 psi | 89% | 2835 fps | 98.7% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 56,927 psi | 89% | 2838 fps | 98.8% |
| Bofors RP15 | <<locked>> | 92% | 55,158 psi | 86% | 2848 fps | 100% |
| Bofors RP15 | <<locked>> | 92% | 55,695 psi | 87% | 2858 fps | 100% |
| Bofors RP30 | <<locked>> | 98% | 57,188 psi | 90% | 2907 fps | 100% |
| Bofors RP30 | <<locked>> | 98% | 57,696 psi | 90% | 2917 fps | 100% |
| Bofors RP5 | <<locked>> | 90% | 55,970 psi | 88% | 2861 fps | 100% |
| Bofors RP5 | <<locked>> | 90% | 56,333 psi | 88% | 2867 fps | 100% |
| Hodgdon H1000 | <<locked>> | 96% | 55,550 psi | 87% | 2861 fps | 100% |
| Hodgdon H1000 | <<locked>> | 96% | 55,883 psi | 88% | 2867 fps | 100% |
| Hodgdon H4831 | <<locked>> | 88% | 55,172 psi | 86% | 2805 fps | 99.7% |
| Hodgdon H4831 | <<locked>> | 88% | 55,535 psi | 87% | 2812 fps | 99.7% |
| Hodgdon H4831 SC | <<locked>> | 88% | 54,157 psi | 85% | 2789 fps | 99.6% |
| Hodgdon H4831 SC | <<locked>> | 88% | 54,520 psi | 85% | 2795 fps | 99.6% |
| Hodgdon Hybrid 100V | <<locked>> | 84% | 54,244 psi | 85% | 2707 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 84% | 54,679 psi | 86% | 2713 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 96% | 56,695 psi | 89% | 2979 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 96% | 57,101 psi | 89% | 2986 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,420 psi | 59% | 1755 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,536 psi | 59% | 1759 fps | 100% |
| IMR 4350 | <<locked>> | 84% | 56,550 psi | 89% | 2772 fps | 100% |
| IMR 4350 | <<locked>> | 84% | 56,753 psi | 89% | 2779 fps | 100% |
| IMR 4831 | <<locked>> | 84% | 56,898 psi | 89% | 2769 fps | 100% |
| IMR 4831 | <<locked>> | 84% | 57,116 psi | 90% | 2776 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 88% | 55,738 psi | 87% | 2782 fps | 99.7% |
| IMR 4955 Enduron | <<locked>> | 88% | 56,086 psi | 88% | 2789 fps | 99.8% |
| IMR 7828 SSC | <<locked>> | 90% | 54,012 psi | 85% | 2851 fps | 99.9% |
| IMR 7828 SSC | <<locked>> | 90% | 54,404 psi | 85% | 2858 fps | 99.9% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 47,442 psi | 74% | 2776 fps | 99.5% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 47,950 psi | 75% | 2789 fps | 99.6% |
| Lovex S065 | <<locked>> | 82% | 56,594 psi | 89% | 2743 fps | 100% |
| Lovex S065 | <<locked>> | 82% | 56,811 psi | 89% | 2749 fps | 100% |
| Lovex S070 | <<locked>> | 82% | 55,042 psi | 86% | 2749 fps | 100% |
| Lovex S070 | <<locked>> | 82% | 55,274 psi | 87% | 2753 fps | 100% |
| Lovex S071 | <<locked>> | 96% | 57,159 psi | 90% | 2779 fps | 100% |
| Lovex S071 | <<locked>> | 96% | 57,551 psi | 90% | 2785 fps | 100% |
| Norma 204 | <<locked>> | 82% | 53,983 psi | 85% | 2779 fps | 100% |
| Norma 204 | <<locked>> | 82% | 54,186 psi | 85% | 2782 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 48,124 psi | 75% | 2799 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 48,675 psi | 76% | 2808 fps | 100% |
| Norma MRP | <<locked>> | 88% | 55,970 psi | 88% | 2877 fps | 100% |
| Norma MRP | <<locked>> | 88% | 56,362 psi | 88% | 2881 fps | 100% |
| Norma URP | <<locked>> | 82% | 54,926 psi | 86% | 2762 fps | 100% |
| Norma URP | <<locked>> | 82% | 55,172 psi | 86% | 2769 fps | 100% |
| Ramshot Grand | <<locked>> | 90% | 54,897 psi | 86% | 2871 fps | 100% |
| Ramshot Grand | <<locked>> | 90% | 55,288 psi | 87% | 2877 fps | 100% |
| Ramshot Hunter | <<locked>> | 84% | 57,551 psi | 90% | 2828 fps | 100% |
| Ramshot Hunter | <<locked>> | 82% | 54,085 psi | 85% | 2779 fps | 100% |
| Ramshot Magnum | <<locked>> | 94% | 57,305 psi | 90% | 2858 fps | 100% |
| Ramshot Magnum | <<locked>> | 92% | 53,563 psi | 84% | 2805 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,319 psi | 60% | 1795 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,435 psi | 60% | 1801 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 56,724 psi | 89% | 2802 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 57,116 psi | 90% | 2808 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 82% | 55,332 psi | 87% | 2831 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 82% | 55,709 psi | 87% | 2838 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 57,406 psi | 90% | 2969 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 94% | 53,679 psi | 84% | 2920 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 56,521 psi | 89% | 2936 fps | 99.8% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 57,029 psi | 89% | 2946 fps | 99.8% |
| Rottweil R 904 | <<locked>> | 86% | 54,723 psi | 86% | 2769 fps | 99.8% |
| Rottweil R 904 | <<locked>> | 86% | 55,071 psi | 86% | 2776 fps | 99.9% |
| Rottweil R 905 | <<locked>> | 88% | 56,710 psi | 89% | 2831 fps | 100% |
| Rottweil R 905 | <<locked>> | 88% | 57,116 psi | 90% | 2838 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 82% | 56,594 psi | 89% | 2743 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 82% | 56,811 psi | 89% | 2749 fps | 100% |
| Shooters World SW4350 | <<locked>> | 82% | 55,042 psi | 86% | 2749 fps | 100% |
| Shooters World SW4350 | <<locked>> | 82% | 55,274 psi | 87% | 2753 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 82% | 55,550 psi | 87% | 2700 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 82% | 55,898 psi | 88% | 2710 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 56,304 psi | 88% | 2828 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 56,695 psi | 89% | 2835 fps | 100% |
| Somchem S361 | <<locked>> | 86% | 55,999 psi | 88% | 2762 fps | 99.7% |
| Somchem S361 | <<locked>> | 86% | 56,304 psi | 88% | 2769 fps | 99.7% |
| Somchem S365 | <<locked>> | 84% | 56,043 psi | 88% | 2762 fps | 100% |
| Somchem S365 | <<locked>> | 84% | 56,318 psi | 88% | 2769 fps | 100% |
| Somchem S385 | <<locked>> | 88% | 57,101 psi | 89% | 2802 fps | 100% |
| Somchem S385 | <<locked>> | 88% | 57,464 psi | 90% | 2808 fps | 100% |
| Vihtavuori N160 | <<locked>> | 82% | 56,434 psi | 88% | 2753 fps | 100% |
| Vihtavuori N160 | <<locked>> | 82% | 56,826 psi | 89% | 2759 fps | 100% |
| Vihtavuori N165 | <<locked>> | 92% | 56,884 psi | 89% | 2785 fps | 100% |
| Vihtavuori N165 | <<locked>> | 92% | 57,217 psi | 90% | 2792 fps | 100% |
| Vihtavuori N170 | <<locked>> | 96% | 55,753 psi | 87% | 2808 fps | 97.1% |
| Vihtavuori N170 | <<locked>> | 96% | 55,999 psi | 88% | 2815 fps | 97.2% |
| Vihtavuori N550 | <<locked>> | 82% | 55,564 psi | 87% | 2759 fps | 100% |
| Vihtavuori N550 | <<locked>> | 82% | 55,956 psi | 88% | 2762 fps | 100% |
| Vihtavuori N555 | <<locked>> | 88% | 55,840 psi | 88% | 2792 fps | 100% |
| Vihtavuori N555 | <<locked>> | 88% | 56,275 psi | 88% | 2799 fps | 100% |
| Vihtavuori N560 | <<locked>> | 88% | 55,593 psi | 87% | 2881 fps | 99.8% |
| Vihtavuori N560 | <<locked>> | 88% | 55,956 psi | 88% | 2887 fps | 99.8% |
| Vihtavuori N565 | <<locked>> | 94% | 55,941 psi | 88% | 2867 fps | 99.9% |
| Vihtavuori N565 | <<locked>> | 94% | 56,304 psi | 88% | 2874 fps | 99.9% |
| Vihtavuori N568 | <<locked>> | 98% | 57,348 psi | 90% | 2940 fps | 99.6% |
| Vihtavuori N568 | <<locked>> | 96% | 53,766 psi | 84% | 2884 fps | 99.3% |
| Vihtavuori N570 | <<locked>> | 98% | 54,302 psi | 85% | 2936 fps | 98.1% |
| Vihtavuori N570 | <<locked>> | 98% | 54,824 psi | 86% | 2946 fps | 98.3% |
| Winchester 6.5 StaBALL | <<locked>> | 82% | 55,883 psi | 88% | 2707 fps | 100% |
| Winchester 6.5 StaBALL | <<locked>> | 82% | 56,246 psi | 88% | 2710 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 92% | 57,072 psi | 89% | 2904 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 90% | 53,403 psi | 84% | 2858 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 90% | 57,072 psi | 89% | 2802 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 90% | 57,406 psi | 90% | 2808 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% | 39,595 psi | 62% | 2503 fps | 99.9% |
| Accurate 3100 | <<locked>> | 80% | 39,842 psi | 62% | 2507 fps | 99.9% |
| Accurate 4350 | <<locked>> | 80% | 52,750 psi | 83% | 2726 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 53,011 psi | 83% | 2733 fps | 100% |
| Accurate High Country | <<locked>> | 80% | 43,511 psi | 68% | 2684 fps | 98.7% |
| Accurate High Country | <<locked>> | 80% | 43,903 psi | 69% | 2690 fps | 98.8% |
| Accurate MAGPRO | <<locked>> | 80% | 41,075 psi | 64% | 2625 fps | 97.1% |
| Accurate MAGPRO | <<locked>> | 80% | 41,307 psi | 65% | 2631 fps | 97.2% |
| ADI AR 2209 | <<locked>> | 80% | 43,961 psi | 69% | 2631 fps | 99.3% |
| ADI AR 2209 | <<locked>> | 80% | 44,208 psi | 69% | 2638 fps | 99.4% |
| ADI AR 2213 | <<locked>> | 80% | 39,276 psi | 62% | 2572 fps | 97.6% |
| ADI AR 2213 | <<locked>> | 80% | 39,595 psi | 62% | 2582 fps | 97.7% |
| ADI AR 2217 | <<locked>> | 84% | 33,330 psi | 52% | 2438 fps | 95.9% |
| ADI AR 2217 | <<locked>> | 84% | 33,504 psi | 53% | 2441 fps | 96% |
| ADI AR 2218 | <<locked>> | 96% | 43,265 psi | 68% | 2740 fps | 95.5% |
| ADI AR 2218 | <<locked>> | 96% | 43,642 psi | 68% | 2749 fps | 95.7% |
| ADI AR 2225 | <<locked>> | 80% | 26,353 psi | 41% | 2283 fps | 95.5% |
| ADI AR 2225 | <<locked>> | 80% | 26,600 psi | 42% | 2293 fps | 95.7% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 44,367 psi | 70% | 2635 fps | 99.4% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 44,599 psi | 70% | 2638 fps | 99.4% |
| Alliant Reloder-16 | <<locked>> | 80% | 50,647 psi | 79% | 2733 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 51,111 psi | 80% | 2740 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 43,961 psi | 69% | 2628 fps | 99.4% |
| Alliant Reloder-19 | <<locked>> | 80% | 44,179 psi | 69% | 2631 fps | 99.4% |
| Alliant Reloder-22 | <<locked>> | 80% | 39,784 psi | 62% | 2579 fps | 98.8% |
| Alliant Reloder-22 | <<locked>> | 80% | 40,132 psi | 63% | 2589 fps | 98.9% |
| Alliant Reloder-23 | <<locked>> | 80% | 38,508 psi | 60% | 2523 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 80% | 38,769 psi | 61% | 2530 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 33,156 psi | 52% | 2464 fps | 99.6% |
| Alliant Reloder-25 | <<locked>> | 80% | 33,359 psi | 52% | 2470 fps | 99.7% |
| Alliant Reloder-26 | <<locked>> | 80% | 43,163 psi | 68% | 2680 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 80% | 43,569 psi | 68% | 2690 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 94% | 43,801 psi | 69% | 2733 fps | 96% |
| Alliant Reloder-33 | <<locked>> | 92% | 40,959 psi | 64% | 2677 fps | 95.1% |
| Alliant Reloder-50 | <<locked>> | 98% | 42,801 psi | 67% | 2710 fps | 95.1% |
| Alliant Reloder-50 | <<locked>> | 98% | 43,221 psi | 68% | 2720 fps | 95.3% |
| Baschieri & Pellagri 109 | <<locked>> | 82% | 41,191 psi | 65% | 2552 fps | 95.1% |
| Baschieri & Pellagri 109 | <<locked>> | 82% | 41,452 psi | 65% | 2562 fps | 95.3% |
| Bofors RP15 | <<locked>> | 80% | 36,941 psi | 58% | 2516 fps | 98% |
| Bofors RP15 | <<locked>> | 80% | 37,275 psi | 58% | 2526 fps | 98.1% |
| Bofors RP30 | <<locked>> | 82% | 32,793 psi | 51% | 2448 fps | 96% |
| Bofors RP30 | <<locked>> | 80% | 30,777 psi | 48% | 2398 fps | 95.1% |
| Bofors RP5 | <<locked>> | 80% | 39,784 psi | 62% | 2579 fps | 98.8% |
| Bofors RP5 | <<locked>> | 80% | 40,132 psi | 63% | 2589 fps | 98.9% |
| Hodgdon H1000 | <<locked>> | 80% | 31,560 psi | 49% | 2392 fps | 95.7% |
| Hodgdon H1000 | <<locked>> | 80% | 31,836 psi | 50% | 2402 fps | 95.9% |
| Hodgdon H4831 | <<locked>> | 80% | 41,930 psi | 66% | 2575 fps | 97.7% |
| Hodgdon H4831 | <<locked>> | 80% | 42,134 psi | 66% | 2582 fps | 97.7% |
| Hodgdon H4831 SC | <<locked>> | 80% | 41,118 psi | 64% | 2559 fps | 97.5% |
| Hodgdon H4831 SC | <<locked>> | 80% | 41,452 psi | 65% | 2569 fps | 97.6% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 47,630 psi | 75% | 2612 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 47,877 psi | 75% | 2618 fps | 100% |
| Hodgdon Retumbo | 86.6 gr | 80% | 32,314 psi | 51% | 2493 fps | 97.4% |
| Hodgdon Retumbo | 86.6 gr | 80% | 32,619 psi | 51% | 2503 fps | 97.6% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,036 psi | 44% | 1568 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,079 psi | 44% | 1572 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 49,690 psi | 78% | 2671 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 49,937 psi | 78% | 2674 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 49,835 psi | 78% | 2671 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 50,270 psi | 79% | 2677 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 43,178 psi | 68% | 2569 fps | 98.1% |
| IMR 4955 Enduron | <<locked>> | 80% | 43,381 psi | 68% | 2575 fps | 98.1% |
| IMR 7828 SSC | <<locked>> | 80% | 37,884 psi | 59% | 2556 fps | 97.3% |
| IMR 7828 SSC | <<locked>> | 80% | 38,232 psi | 60% | 2562 fps | 97.4% |
| IMR 8133 Enduron | <<locked>> | 88% | 31,386 psi | 49% | 2434 fps | 95.1% |
| IMR 8133 Enduron | <<locked>> | 88% | 31,662 psi | 50% | 2441 fps | 95.3% |
| Lovex S065 | <<locked>> | 80% | 53,142 psi | 83% | 2697 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 53,388 psi | 84% | 2700 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 51,517 psi | 81% | 2697 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 51,924 psi | 81% | 2703 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 33,953 psi | 53% | 2385 fps | 99.1% |
| Lovex S071 | <<locked>> | 80% | 34,185 psi | 54% | 2388 fps | 99.2% |
| Norma 204 | <<locked>> | 80% | 50,386 psi | 79% | 2723 fps | 99.9% |
| Norma 204 | <<locked>> | 80% | 50,633 psi | 79% | 2726 fps | 99.9% |
| Norma 217 | <<locked>> | 84% | 27,369 psi | 43% | 2339 fps | 95.5% |
| Norma 217 | <<locked>> | 84% | 27,572 psi | 43% | 2346 fps | 95.7% |
| Norma MRP | <<locked>> | 80% | 42,076 psi | 66% | 2648 fps | 99.8% |
| Norma MRP | <<locked>> | 80% | 42,453 psi | 67% | 2654 fps | 99.8% |
| Norma URP | <<locked>> | 80% | 51,314 psi | 80% | 2710 fps | 100% |
| Norma URP | <<locked>> | 80% | 51,706 psi | 81% | 2720 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 37,753 psi | 59% | 2566 fps | 97.7% |
| Ramshot Grand | <<locked>> | 80% | 38,000 psi | 60% | 2572 fps | 97.8% |
| Ramshot Hunter | <<locked>> | 80% | 50,372 psi | 79% | 2723 fps | 100% |
| Ramshot Hunter | <<locked>> | 80% | 50,604 psi | 79% | 2726 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 33,591 psi | 53% | 2444 fps | 98% |
| Ramshot Magnum | <<locked>> | 80% | 33,910 psi | 53% | 2454 fps | 98.1% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,790 psi | 45% | 1608 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,819 psi | 45% | 1611 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 52,982 psi | 83% | 2753 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 53,243 psi | 83% | 2756 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 51,547 psi | 81% | 2779 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 51,822 psi | 81% | 2782 fps | 100% |
| ReloadSwiss RS 76 | 92.7 gr | 80% | 31,372 psi | 49% | 2467 fps | 98.2% |
| ReloadSwiss RS 76 | 92.7 gr | 80% | 31,676 psi | 50% | 2477 fps | 98.3% |
| ReloadSwiss RS 80 | <<locked>> | 86% | 35,549 psi | 56% | 2549 fps | 95.4% |
| ReloadSwiss RS 80 | <<locked>> | 86% | 35,824 psi | 56% | 2556 fps | 95.6% |
| Rottweil R 904 | <<locked>> | 80% | 45,034 psi | 71% | 2608 fps | 98.8% |
| Rottweil R 904 | <<locked>> | 80% | 45,266 psi | 71% | 2615 fps | 98.9% |
| Rottweil R 905 | <<locked>> | 80% | 43,337 psi | 68% | 2615 fps | 99.4% |
| Rottweil R 905 | <<locked>> | 80% | 43,714 psi | 69% | 2621 fps | 99.4% |
| Shooters World Long Rifle | <<locked>> | 80% | 53,142 psi | 83% | 2697 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 80% | 53,388 psi | 84% | 2700 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 51,517 psi | 81% | 2697 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 51,924 psi | 81% | 2703 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 52,083 psi | 82% | 2654 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 52,315 psi | 82% | 2657 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 43,004 psi | 67% | 2608 fps | 99.3% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 43,381 psi | 68% | 2618 fps | 99.4% |
| Somchem S361 | <<locked>> | 80% | 45,832 psi | 72% | 2598 fps | 98.4% |
| Somchem S361 | <<locked>> | 80% | 46,006 psi | 72% | 2602 fps | 98.5% |
| Somchem S365 | <<locked>> | 80% | 48,849 psi | 77% | 2664 fps | 100% |
| Somchem S365 | <<locked>> | 80% | 49,153 psi | 77% | 2671 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 43,743 psi | 69% | 2592 fps | 99.7% |
| Somchem S385 | <<locked>> | 80% | 44,106 psi | 69% | 2598 fps | 99.8% |
| Vihtavuori N160 | <<locked>> | 80% | 52,895 psi | 83% | 2703 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 53,127 psi | 83% | 2707 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 38,116 psi | 60% | 2474 fps | 98.8% |
| Vihtavuori N165 | <<locked>> | 80% | 38,348 psi | 60% | 2480 fps | 98.8% |
| Vihtavuori N170 | <<locked>> | 92% | 48,530 psi | 76% | 2694 fps | 95.5% |
| Vihtavuori N170 | <<locked>> | 92% | 48,805 psi | 76% | 2700 fps | 95.6% |
| Vihtavuori N550 | <<locked>> | 80% | 52,011 psi | 82% | 2710 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 52,417 psi | 82% | 2713 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 42,859 psi | 67% | 2595 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 43,105 psi | 68% | 2602 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 41,959 psi | 66% | 2641 fps | 97.9% |
| Vihtavuori N560 | <<locked>> | 80% | 42,322 psi | 66% | 2651 fps | 98% |
| Vihtavuori N565 | <<locked>> | 80% | 34,403 psi | 54% | 2464 fps | 95.7% |
| Vihtavuori N565 | <<locked>> | 80% | 34,722 psi | 54% | 2470 fps | 95.9% |
| Vihtavuori N568 | <<locked>> | 86% | 37,028 psi | 58% | 2569 fps | 95.3% |
| Vihtavuori N568 | <<locked>> | 86% | 37,333 psi | 59% | 2575 fps | 95.5% |
| Vihtavuori N570 | 103.3 gr | 92% | 43,598 psi | 68% | 2743 fps | 95.5% |
| Vihtavuori N570 | 103.3 gr | 92% | 43,947 psi | 69% | 2753 fps | 95.7% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 52,156 psi | 82% | 2657 fps | 100% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 52,518 psi | 82% | 2664 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 35,897 psi | 56% | 2575 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 36,187 psi | 57% | 2579 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 40,161 psi | 63% | 2526 fps | 98.8% |
| Winchester Supreme 780 | <<locked>> | 80% | 40,509 psi | 63% | 2533 fps | 98.9% |
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 138 powders for .338-378 Weath. Mag. loaded with the .338 | 254gr | CutEdge MTAC. Hodgdon Retumbo delivers the highest muzzle velocity at 2,986 fps; across all powders the maximum-charge window runs from 1,755 fps to 2,986 fps. ADI AR 2218 gives the best case fill at 100 %, and 138 of the 138 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 254.0 gr projectile in 0.338" calls for a 1:10.5 twist; slower twists will usually not stabilise this weight. ADI AR 2218, 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 N570 rank at the top here: for .338-378 Weath. Mag. with the .338 | 254gr | CutEdge MTAC 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.