Load Specifications
Load data in caliber .340 Weath. Mag. with .338 | 250gr | Speer Grand Slam bullet and 92 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Accurate High Country, Alliant Reloder-26 and Norma MRP.
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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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 2700 | <<locked>> | 82% | 55,593 psi | 87% | 2628 fps | 99.7% |
| Accurate 3100 | <<locked>> | 98% | 54,273 psi | 85% | 2684 fps | 100% |
| Accurate 4064 | <<locked>> | 82% | 55,506 psi | 87% | 2605 fps | 100% |
| Accurate 4350 | <<locked>> | 90% | 56,405 psi | 88% | 2720 fps | 100% |
| Accurate High Country | <<locked>> | 96% | 55,448 psi | 87% | 2828 fps | 98.9% |
| Accurate MAGPRO | <<locked>> | 98% | 56,521 psi | 89% | 2831 fps | 98.1% |
| ADI AR 2208 | <<locked>> | 84% | 55,158 psi | 86% | 2638 fps | 100% |
| ADI AR 2209 | <<locked>> | 96% | 57,029 psi | 89% | 2772 fps | 99.5% |
| ADI AR 2213 | <<locked>> | 98% | 54,636 psi | 86% | 2772 fps | 98.6% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 42,670 psi | 67% | 2556 fps | 96.1% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 37,623 psi | 59% | 2520 fps | 97.9% |
| Alliant Power Pro Varmint | <<locked>> | 96% | 57,319 psi | 90% | 2769 fps | 99.5% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 56,159 psi | 88% | 2657 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 56,318 psi | 88% | 2680 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 92% | 57,159 psi | 90% | 2772 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 86% | 54,737 psi | 86% | 2743 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 96% | 56,536 psi | 89% | 2762 fps | 99.5% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 57,725 psi | 90% | 2825 fps | 99.7% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 54,766 psi | 86% | 2743 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 47,326 psi | 74% | 2694 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 96% | 55,013 psi | 86% | 2835 fps | 100% |
| Baschieri & Pellagri 109ᴾ | <<locked>> | 100% | 57,188 psi | 90% | 2736 fps | 96.2% |
| Bofors RP15ᴾ | <<locked>> | 100% | 52,953 psi | 83% | 2753 fps | 99.2% |
| Bofors RP3 | <<locked>> | 84% | 57,101 psi | 89% | 2674 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 43,279 psi | 68% | 2628 fps | 97.1% |
| Bofors RP5ᴾ | <<locked>> | 100% | 57,725 psi | 90% | 2825 fps | 99.7% |
| Bofors RP7 | <<locked>> | 88% | 56,231 psi | 88% | 2674 fps | 99.8% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 46,934 psi | 74% | 2641 fps | 97.9% |
| Hodgdon H380 | <<locked>> | 84% | 57,188 psi | 90% | 2694 fps | 100% |
| Hodgdon H414 | <<locked>> | 88% | 54,839 psi | 86% | 2726 fps | 99.9% |
| Hodgdon H4350 | <<locked>> | 86% | 54,418 psi | 85% | 2684 fps | 99.4% |
| Hodgdon H4831 | <<locked>> | 96% | 54,926 psi | 86% | 2720 fps | 98% |
| Hodgdon H4831 SC | <<locked>> | 98% | 57,363 psi | 90% | 2753 fps | 98.4% |
| Hodgdon Hybrid 100V | <<locked>> | 94% | 57,493 psi | 90% | 2694 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 46,325 psi | 73% | 2743 fps | 99.1% |
| Hodgdon Superformance | <<locked>> | 88% | 54,853 psi | 86% | 2762 fps | 99.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,666 psi | 57% | 1640 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 54,665 psi | 86% | 2621 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 56,884 psi | 89% | 2657 fps | 99.9% |
| IMR 4350 | <<locked>> | 92% | 57,435 psi | 90% | 2710 fps | 99.9% |
| IMR 4451 Enduron | <<locked>> | 86% | 54,259 psi | 85% | 2644 fps | 99.8% |
| IMR 4831 | <<locked>> | 92% | 56,768 psi | 89% | 2713 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 56,202 psi | 88% | 2700 fps | 98.3% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 55,999 psi | 88% | 2805 fps | 98.9% |
| Lovex S062 | <<locked>> | 82% | 54,911 psi | 86% | 2612 fps | 100% |
| Lovex S065 | <<locked>> | 88% | 54,723 psi | 86% | 2644 fps | 100% |
| Lovex S070 | <<locked>> | 90% | 55,956 psi | 88% | 2687 fps | 100% |
| Lovex S071ᴾ | <<locked>> | 100% | 48,428 psi | 76% | 2598 fps | 99.8% |
| Norma 203B | <<locked>> | 82% | 55,666 psi | 87% | 2667 fps | 100% |
| Norma 204 | <<locked>> | 90% | 54,418 psi | 85% | 2710 fps | 99.2% |
| Norma MRP | <<locked>> | 98% | 57,580 psi | 90% | 2851 fps | 100% |
| Norma URP | <<locked>> | 90% | 54,998 psi | 86% | 2707 fps | 100% |
| Ramshot Big Game | <<locked>> | 82% | 56,376 psi | 88% | 2694 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 56,594 psi | 89% | 2825 fps | 99.2% |
| Ramshot Hunter | <<locked>> | 92% | 57,421 psi | 90% | 2766 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 50,517 psi | 79% | 2707 fps | 99.5% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,521 psi | 59% | 1680 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 57,000 psi | 89% | 2684 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 54,012 psi | 85% | 2726 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 56,289 psi | 88% | 2746 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 54,563 psi | 86% | 2776 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 46,383 psi | 73% | 2740 fps | 99.7% |
| Rottweil R 902 | <<locked>> | 82% | 56,724 psi | 89% | 2618 fps | 100% |
| Rottweil R 903 | <<locked>> | 86% | 57,217 psi | 90% | 2671 fps | 100% |
| Rottweil R 904 | <<locked>> | 94% | 55,085 psi | 86% | 2690 fps | 98.6% |
| Rottweil R 905 | <<locked>> | 96% | 55,927 psi | 88% | 2749 fps | 99.5% |
| Rottweil R 907 | <<locked>> | 88% | 56,231 psi | 88% | 2674 fps | 99.8% |
| Shooters World Long Rifle | <<locked>> | 88% | 54,723 psi | 86% | 2644 fps | 100% |
| Shooters World Precision | <<locked>> | 82% | 54,911 psi | 86% | 2612 fps | 100% |
| Shooters World SW4350 | <<locked>> | 90% | 55,956 psi | 88% | 2687 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 55,100 psi | 86% | 2684 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 57,740 psi | 90% | 2549 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 57,653 psi | 90% | 2651 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 96% | 55,448 psi | 87% | 2746 fps | 99.5% |
| Somchem S355 | <<locked>> | 86% | 56,898 psi | 89% | 2664 fps | 100% |
| Somchem S361 | <<locked>> | 94% | 56,739 psi | 89% | 2687 fps | 98.2% |
| Somchem S365 | <<locked>> | 92% | 54,737 psi | 86% | 2707 fps | 100% |
| Somchem S385 | <<locked>> | 96% | 56,333 psi | 88% | 2723 fps | 99.8% |
| Vihtavuori N135 | <<locked>> | 82% | 57,421 psi | 90% | 2575 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 57,334 psi | 90% | 2592 fps | 100% |
| Vihtavuori N150 | <<locked>> | 86% | 54,694 psi | 86% | 2595 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 56,985 psi | 89% | 2697 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 55,753 psi | 87% | 2703 fps | 99.7% |
| Vihtavuori N540 | <<locked>> | 82% | 55,622 psi | 87% | 2595 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 55,970 psi | 88% | 2703 fps | 100% |
| Vihtavuori N555 | <<locked>> | 98% | 57,479 psi | 90% | 2769 fps | 100% |
| Vihtavuori N560 | <<locked>> | 98% | 57,667 psi | 90% | 2844 fps | 98.7% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 49,487 psi | 78% | 2707 fps | 97.7% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 56,521 psi | 89% | 2664 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 54,839 psi | 86% | 2726 fps | 99.9% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 50,517 psi | 79% | 2818 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 98% | 56,521 psi | 89% | 2720 fps | 99.4% |
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% | 52,170 psi | 82% | 2579 fps | 99.4% |
| Accurate 3100 | <<locked>> | 80% | 29,689 psi | 47% | 2231 fps | 95.9% |
| Accurate 4064 | <<locked>> | 80% | 52,199 psi | 82% | 2562 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 40,234 psi | 63% | 2467 fps | 99.7% |
| Accurate High Country | 74.4 gr | 86% | 39,305 psi | 62% | 2543 fps | 95.4% |
| Accurate MAGPRO | <<locked>> | 92% | 45,759 psi | 72% | 2657 fps | 95.9% |
| ADI AR 2208 | <<locked>> | 80% | 48,849 psi | 77% | 2546 fps | 100% |
| ADI AR 2209 | <<locked>> | 82% | 36,260 psi | 57% | 2402 fps | 95.2% |
| ADI AR 2213 | <<locked>> | 90% | 41,974 psi | 66% | 2549 fps | 95.7% |
| ADI AR 2217 | <<locked>> | 98% | 40,059 psi | 63% | 2503 fps | 95.2% |
| ADI AR 2225 | <<locked>> | 96% | 33,257 psi | 52% | 2408 fps | 96% |
| Alliant Power Pro Varmint | <<locked>> | 82% | 36,492 psi | 57% | 2405 fps | 95.4% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 49,516 psi | 78% | 2566 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 52,808 psi | 83% | 2631 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 38,914 psi | 61% | 2477 fps | 99.8% |
| Alliant Reloder-17 | <<locked>> | 80% | 44,353 psi | 70% | 2589 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 82% | 36,143 psi | 57% | 2398 fps | 95.4% |
| Alliant Reloder-22 | <<locked>> | 86% | 36,347 psi | 57% | 2448 fps | 95.7% |
| Alliant Reloder-23 | <<locked>> | 80% | 28,703 psi | 45% | 2260 fps | 98.9% |
| Alliant Reloder-25 | <<locked>> | 84% | 28,660 psi | 45% | 2277 fps | 95.8% |
| Alliant Reloder-26 | 71.3 gr | 80% | 30,719 psi | 48% | 2375 fps | 97.8% |
| Baschieri & Pellagri 109 | <<locked>> | 98% | 53,896 psi | 84% | 2684 fps | 95.4% |
| Bofors RP15 | <<locked>> | 88% | 36,042 psi | 56% | 2441 fps | 95.3% |
| Bofors RP3 | <<locked>> | 80% | 50,038 psi | 78% | 2579 fps | 100% |
| Bofors RP30 | <<locked>> | 96% | 38,000 psi | 60% | 2520 fps | 95.4% |
| Bofors RP5 | <<locked>> | 86% | 36,347 psi | 57% | 2448 fps | 95.7% |
| Bofors RP7 | <<locked>> | 80% | 43,874 psi | 69% | 2474 fps | 98.4% |
| Hodgdon H1000 | <<locked>> | 94% | 38,450 psi | 60% | 2474 fps | 95.3% |
| Hodgdon H380 | <<locked>> | 80% | 50,415 psi | 79% | 2598 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 41,974 psi | 66% | 2513 fps | 98.6% |
| Hodgdon H4350 | <<locked>> | 80% | 44,817 psi | 70% | 2526 fps | 98% |
| Hodgdon H4831 | <<locked>> | 88% | 41,945 psi | 66% | 2500 fps | 95% |
| Hodgdon H4831 SC | <<locked>> | 90% | 43,990 psi | 69% | 2539 fps | 95.7% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 36,593 psi | 57% | 2372 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 92% | 35,955 psi | 56% | 2510 fps | 96% |
| Hodgdon Superformance | <<locked>> | 80% | 40,872 psi | 64% | 2530 fps | 98.1% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,412 psi | 43% | 1463 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 51,416 psi | 81% | 2575 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 53,592 psi | 84% | 2608 fps | 99.8% |
| IMR 4350 | <<locked>> | 80% | 39,479 psi | 62% | 2411 fps | 97.5% |
| IMR 4451 Enduron | <<locked>> | 80% | 45,179 psi | 71% | 2500 fps | 98.9% |
| IMR 4831 | <<locked>> | 80% | 38,580 psi | 60% | 2421 fps | 99.6% |
| IMR 4955 Enduron | <<locked>> | 86% | 41,307 psi | 65% | 2451 fps | 95% |
| IMR 7828 SSC | <<locked>> | 90% | 40,118 psi | 63% | 2523 fps | 95.2% |
| Lovex S062 | <<locked>> | 80% | 51,663 psi | 81% | 2566 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 42,830 psi | 67% | 2454 fps | 99.4% |
| Lovex S070 | <<locked>> | 80% | 41,060 psi | 64% | 2441 fps | 98.5% |
| Lovex S071 | <<locked>> | 84% | 29,095 psi | 46% | 2215 fps | 95.6% |
| Norma 203B | <<locked>> | 80% | 52,199 psi | 82% | 2618 fps | 100% |
| Norma 204 | <<locked>> | 80% | 38,986 psi | 61% | 2441 fps | 96.1% |
| Norma MRP | 70.9 gr | 82% | 33,069 psi | 52% | 2398 fps | 95.9% |
| Norma URP | <<locked>> | 80% | 39,842 psi | 62% | 2461 fps | 99.7% |
| Ramshot Big Game | <<locked>> | 80% | 52,634 psi | 82% | 2644 fps | 100% |
| Ramshot Grand | <<locked>> | 90% | 39,711 psi | 62% | 2530 fps | 95.5% |
| Ramshot Hunter | <<locked>> | 80% | 38,638 psi | 61% | 2454 fps | 98.5% |
| Ramshot Magnum | <<locked>> | 90% | 35,215 psi | 55% | 2418 fps | 96% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,079 psi | 44% | 1499 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 50,227 psi | 79% | 2585 fps | 99.8% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 47,094 psi | 74% | 2628 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 40,001 psi | 63% | 2487 fps | 99.6% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 38,464 psi | 60% | 2497 fps | 99.4% |
| ReloadSwiss RS 76 | <<locked>> | 90% | 32,822 psi | 51% | 2428 fps | 95.7% |
| Rottweil R 902 | <<locked>> | 80% | 53,388 psi | 84% | 2575 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 47,253 psi | 74% | 2533 fps | 100% |
| Rottweil R 904 | <<locked>> | 84% | 40,263 psi | 63% | 2438 fps | 95.4% |
| Rottweil R 905 | <<locked>> | 82% | 35,302 psi | 55% | 2385 fps | 95.3% |
| Rottweil R 907 | <<locked>> | 80% | 43,874 psi | 69% | 2474 fps | 98.4% |
| Shooters World Long Rifle | <<locked>> | 80% | 42,830 psi | 67% | 2454 fps | 99.4% |
| Shooters World Precision | <<locked>> | 80% | 51,663 psi | 81% | 2566 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 41,060 psi | 64% | 2441 fps | 98.5% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 48,385 psi | 76% | 2585 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 48,109 psi | 75% | 2428 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 41,930 psi | 66% | 2405 fps | 98.5% |
| SNPE Vectan Tubal 8000 | <<locked>> | 82% | 34,969 psi | 55% | 2379 fps | 95.2% |
| Somchem S355 | <<locked>> | 80% | 47,398 psi | 74% | 2530 fps | 100% |
| Somchem S361 | <<locked>> | 86% | 43,598 psi | 68% | 2477 fps | 95.5% |
| Somchem S365 | <<locked>> | 80% | 36,463 psi | 57% | 2425 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 33,533 psi | 53% | 2316 fps | 95.6% |
| Vihtavuori N135 | <<locked>> | 80% | 53,940 psi | 85% | 2533 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 53,969 psi | 85% | 2549 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 45,252 psi | 71% | 2461 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 41,205 psi | 65% | 2454 fps | 99.8% |
| Vihtavuori N165 | <<locked>> | 86% | 35,302 psi | 55% | 2352 fps | 95.8% |
| Vihtavuori N540 | <<locked>> | 80% | 52,214 psi | 82% | 2549 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 40,683 psi | 64% | 2461 fps | 99.6% |
| Vihtavuori N555 | <<locked>> | 80% | 31,894 psi | 50% | 2329 fps | 98.8% |
| Vihtavuori N560 | <<locked>> | 88% | 41,017 psi | 64% | 2559 fps | 95.1% |
| Vihtavuori N565 | <<locked>> | 94% | 40,234 psi | 63% | 2539 fps | 95.2% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 40,205 psi | 63% | 2425 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 42,148 psi | 66% | 2513 fps | 98.6% |
| Winchester StaBALL HD | <<locked>> | 80% | 25,396 psi | 40% | 2257 fps | 98.6% |
| Winchester Supreme 780 | <<locked>> | 86% | 37,420 psi | 59% | 2402 fps | 95.8% |
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 92 powders for .340 Weath. Mag. loaded with the .338 | 250gr | Speer Grand Slam. Norma MRP delivers the highest muzzle velocity at 2,851 fps; across all powders the maximum-charge window runs from 1,640 fps to 2,851 fps. ADI AR 2217 gives the best case fill at 100 %, and 92 of the 92 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. The 250.0 gr projectile in 0.338" calls for a 1:6.0 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2225, 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. Accurate High Country, Alliant Reloder-26, Norma MRP rank at the top here: for .340 Weath. Mag. with the .338 | 250gr | Speer Grand Slam 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.