Load Specifications
Load data in caliber .338 Rem. Ultra Mag. with .338 | 225gr | Hornady GMX bullet and 92 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-26, Norma MRP and Vihtavuori N560.
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: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2495 | <<locked>> | 82% | 56,594 psi | 89% | 2621 fps | 100% |
| Accurate 2700 | <<locked>> | 82% | 54,462 psi | 85% | 2654 fps | 99.2% |
| Accurate 3100ᴾ | <<locked>> | 100% | 56,753 psi | 89% | 2746 fps | 100% |
| Accurate 4064 | <<locked>> | 84% | 56,985 psi | 89% | 2677 fps | 100% |
| Accurate 4350 | <<locked>> | 90% | 54,868 psi | 86% | 2743 fps | 100% |
| Accurate MAGPRO | <<locked>> | 98% | 55,448 psi | 87% | 2835 fps | 97.2% |
| ADI AR 2208 | <<locked>> | 86% | 57,464 psi | 90% | 2717 fps | 100% |
| ADI AR 2209 | <<locked>> | 96% | 56,115 psi | 88% | 2789 fps | 99% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 57,537 psi | 90% | 2841 fps | 98.4% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 36,709 psi | 58% | 2510 fps | 96.5% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 57,290 psi | 90% | 2835 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 96% | 56,115 psi | 88% | 2785 fps | 99% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 54,665 psi | 86% | 2687 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 54,882 psi | 86% | 2710 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 92% | 55,767 psi | 87% | 2795 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 88% | 57,406 psi | 90% | 2815 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 96% | 55,361 psi | 87% | 2776 fps | 99% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 56,666 psi | 89% | 2835 fps | 99.3% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 53,534 psi | 84% | 2759 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 46,296 psi | 73% | 2700 fps | 99.9% |
| Alliant Reloder-26 | <<locked>> | 96% | 53,664 psi | 84% | 2841 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 51,938 psi | 81% | 2762 fps | 98.6% |
| Bofors RP3 | <<locked>> | 84% | 55,506 psi | 87% | 2703 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 56,666 psi | 89% | 2835 fps | 99.3% |
| Bofors RP7 | <<locked>> | 88% | 54,984 psi | 86% | 2697 fps | 99.4% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 45,890 psi | 72% | 2641 fps | 96.8% |
| Hodgdon H380 | <<locked>> | 84% | 55,927 psi | 88% | 2723 fps | 100% |
| Hodgdon H414 | <<locked>> | 90% | 57,203 psi | 90% | 2792 fps | 99.8% |
| Hodgdon H4350 | <<locked>> | 88% | 56,724 psi | 89% | 2756 fps | 99.2% |
| Hodgdon H4831 | <<locked>> | 98% | 57,667 psi | 90% | 2785 fps | 97.8% |
| Hodgdon H4831 SC | <<locked>> | 98% | 56,507 psi | 89% | 2769 fps | 97.6% |
| Hodgdon Hybrid 100V | <<locked>> | 94% | 56,188 psi | 88% | 2720 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 57,319 psi | 90% | 2749 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 45,411 psi | 71% | 2743 fps | 98.2% |
| Hodgdon Superformance | <<locked>> | 88% | 53,722 psi | 84% | 2772 fps | 99.5% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,419 psi | 57% | 1699 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 56,782 psi | 89% | 2700 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 55,811 psi | 87% | 2687 fps | 99.7% |
| IMR 4350 | <<locked>> | 92% | 56,246 psi | 88% | 2730 fps | 99.5% |
| IMR 4451 Enduron | <<locked>> | 88% | 56,768 psi | 89% | 2723 fps | 99.7% |
| IMR 4831 | <<locked>> | 92% | 55,390 psi | 87% | 2733 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 56,333 psi | 88% | 2736 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 55,390 psi | 87% | 2720 fps | 97.6% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 54,998 psi | 86% | 2815 fps | 98.1% |
| Lovex S062 | <<locked>> | 84% | 56,811 psi | 89% | 2687 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 56,695 psi | 89% | 2713 fps | 100% |
| Lovex S070 | <<locked>> | 90% | 54,549 psi | 85% | 2707 fps | 99.7% |
| Lovex S071ᴾ | <<locked>> | 100% | 46,876 psi | 73% | 2605 fps | 99.4% |
| Norma 203B | <<locked>> | 84% | 57,725 psi | 90% | 2743 fps | 100% |
| Norma 204 | <<locked>> | 92% | 57,246 psi | 90% | 2782 fps | 99% |
| Norma MRP | <<locked>> | 98% | 56,405 psi | 88% | 2858 fps | 99.9% |
| Norma URP | <<locked>> | 92% | 57,203 psi | 90% | 2776 fps | 100% |
| Ramshot Big Game | <<locked>> | 82% | 55,085 psi | 86% | 2720 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 55,579 psi | 87% | 2831 fps | 98.5% |
| Ramshot Hunter | <<locked>> | 92% | 56,231 psi | 88% | 2782 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 49,647 psi | 78% | 2710 fps | 98.9% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,144 psi | 58% | 1742 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 55,753 psi | 87% | 2707 fps | 99.9% |
| ReloadSwiss RS 60 | <<locked>> | 86% | 56,855 psi | 89% | 2805 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 54,940 psi | 86% | 2762 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 57,479 psi | 90% | 2844 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 45,397 psi | 71% | 2733 fps | 99.1% |
| Rottweil R 902 | <<locked>> | 82% | 55,347 psi | 87% | 2654 fps | 100% |
| Rottweil R 903 | <<locked>> | 86% | 55,579 psi | 87% | 2700 fps | 100% |
| Rottweil R 904 | <<locked>> | 96% | 57,711 psi | 90% | 2759 fps | 98.4% |
| Rottweil R 905 | <<locked>> | 96% | 54,621 psi | 86% | 2762 fps | 99% |
| Rottweil R 907 | <<locked>> | 88% | 54,984 psi | 86% | 2697 fps | 99.4% |
| Shooters World Long Rifle | <<locked>> | 90% | 56,695 psi | 89% | 2713 fps | 100% |
| Shooters World Precision | <<locked>> | 84% | 56,811 psi | 89% | 2687 fps | 100% |
| Shooters World SW4350 | <<locked>> | 90% | 54,549 psi | 85% | 2707 fps | 99.7% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 57,653 psi | 90% | 2759 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 56,478 psi | 89% | 2585 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 56,289 psi | 88% | 2671 fps | 99.7% |
| SNPE Vectan Tubal 8000 | <<locked>> | 96% | 54,172 psi | 85% | 2759 fps | 98.9% |
| Somchem S355 | <<locked>> | 86% | 55,492 psi | 87% | 2694 fps | 100% |
| Somchem S361 | <<locked>> | 94% | 55,796 psi | 87% | 2700 fps | 97.4% |
| Somchem S365 | <<locked>> | 94% | 57,029 psi | 89% | 2776 fps | 100% |
| Somchem S385 | <<locked>> | 96% | 55,129 psi | 86% | 2736 fps | 99.5% |
| Vihtavuori N135 | <<locked>> | 82% | 55,883 psi | 88% | 2612 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 55,999 psi | 88% | 2628 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 56,913 psi | 89% | 2667 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 55,753 psi | 87% | 2720 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 54,723 psi | 86% | 2713 fps | 99.2% |
| Vihtavuori N540 | <<locked>> | 82% | 54,172 psi | 85% | 2625 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 54,853 psi | 86% | 2726 fps | 100% |
| Vihtavuori N555 | <<locked>> | 98% | 55,883 psi | 88% | 2782 fps | 100% |
| Vihtavuori N560 | <<locked>> | 98% | 56,536 psi | 89% | 2851 fps | 98% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 48,182 psi | 76% | 2703 fps | 96.6% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 55,535 psi | 87% | 2687 fps | 100% |
| Winchester 760 | <<locked>> | 90% | 57,406 psi | 90% | 2795 fps | 99.8% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 49,385 psi | 77% | 2825 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 98% | 55,564 psi | 87% | 2736 fps | 98.9% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2495 | <<locked>> | 80% | 52,910 psi | 83% | 2579 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 50,937 psi | 80% | 2602 fps | 98.8% |
| Accurate 3100 | <<locked>> | 84% | 32,329 psi | 51% | 2326 fps | 95.9% |
| Accurate 4064 | <<locked>> | 80% | 50,198 psi | 79% | 2589 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 38,566 psi | 60% | 2477 fps | 99.1% |
| Accurate MAGPRO | <<locked>> | 94% | 47,848 psi | 75% | 2713 fps | 95.5% |
| ADI AR 2208 | <<locked>> | 80% | 47,442 psi | 74% | 2572 fps | 100% |
| ADI AR 2209 | <<locked>> | 86% | 40,045 psi | 63% | 2513 fps | 95.5% |
| ADI AR 2213 | <<locked>> | 92% | 43,801 psi | 69% | 2612 fps | 95.3% |
| ADI AR 2225 | <<locked>> | 98% | 34,316 psi | 54% | 2451 fps | 95.3% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 53,330 psi | 84% | 2782 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 86% | 40,205 psi | 63% | 2516 fps | 95.7% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 48,022 psi | 75% | 2592 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 51,459 psi | 81% | 2661 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 37,594 psi | 59% | 2490 fps | 99.2% |
| Alliant Reloder-17 | <<locked>> | 80% | 42,844 psi | 67% | 2602 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 86% | 39,798 psi | 62% | 2507 fps | 95.6% |
| Alliant Reloder-22 | <<locked>> | 88% | 37,521 psi | 59% | 2500 fps | 95% |
| Alliant Reloder-23 | <<locked>> | 80% | 27,354 psi | 43% | 2254 fps | 97.4% |
| Alliant Reloder-25 | <<locked>> | 88% | 31,140 psi | 49% | 2369 fps | 95.9% |
| Alliant Reloder-26 | 74 gr | 80% | 29,254 psi | 46% | 2356 fps | 95.9% |
| Bofors RP15 | <<locked>> | 92% | 39,581 psi | 62% | 2543 fps | 95.6% |
| Bofors RP3 | <<locked>> | 80% | 48,414 psi | 76% | 2605 fps | 100% |
| Bofors RP5 | <<locked>> | 88% | 37,521 psi | 59% | 2500 fps | 95% |
| Bofors RP7 | <<locked>> | 80% | 42,467 psi | 67% | 2490 fps | 97.4% |
| Hodgdon H1000 | <<locked>> | 98% | 42,873 psi | 67% | 2585 fps | 95.9% |
| Hodgdon H380 | <<locked>> | 80% | 48,907 psi | 77% | 2621 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 80% | 40,712 psi | 64% | 2523 fps | 97.5% |
| Hodgdon H4350 | <<locked>> | 80% | 43,555 psi | 68% | 2539 fps | 97% |
| Hodgdon H4831 | <<locked>> | 92% | 46,891 psi | 73% | 2618 fps | 95.5% |
| Hodgdon H4831 SC | <<locked>> | 92% | 45,977 psi | 72% | 2602 fps | 95.3% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 35,012 psi | 55% | 2382 fps | 99.5% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 53,548 psi | 84% | 2700 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 94% | 37,173 psi | 58% | 2556 fps | 95.2% |
| Hodgdon Superformance | <<locked>> | 80% | 39,740 psi | 62% | 2536 fps | 97% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,166 psi | 43% | 1522 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 49,908 psi | 78% | 2602 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 52,199 psi | 82% | 2635 fps | 99.4% |
| IMR 4350 | <<locked>> | 80% | 38,159 psi | 60% | 2421 fps | 96.2% |
| IMR 4451 Enduron | <<locked>> | 80% | 43,918 psi | 69% | 2520 fps | 98.1% |
| IMR 4831 | <<locked>> | 80% | 36,985 psi | 58% | 2431 fps | 98.9% |
| IMR 4895 | <<locked>> | 80% | 52,808 psi | 83% | 2687 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 45,774 psi | 72% | 2566 fps | 95.4% |
| IMR 7828 SSC | <<locked>> | 94% | 44,715 psi | 70% | 2641 fps | 95.7% |
| Lovex S062 | <<locked>> | 80% | 50,154 psi | 79% | 2598 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 41,394 psi | 65% | 2470 fps | 98.7% |
| Lovex S070 | <<locked>> | 80% | 39,566 psi | 62% | 2454 fps | 97.4% |
| Lovex S071 | <<locked>> | 88% | 31,401 psi | 49% | 2303 fps | 95.5% |
| Norma 203B | <<locked>> | 80% | 50,821 psi | 80% | 2648 fps | 100% |
| Norma 204 | <<locked>> | 82% | 40,437 psi | 63% | 2503 fps | 95.6% |
| Norma MRP | 75.5 gr | 84% | 34,200 psi | 54% | 2451 fps | 95.2% |
| Norma URP | <<locked>> | 80% | 38,319 psi | 60% | 2470 fps | 99% |
| Ramshot Big Game | <<locked>> | 80% | 51,474 psi | 81% | 2671 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 41,466 psi | 65% | 2589 fps | 95% |
| Ramshot Hunter | <<locked>> | 80% | 37,246 psi | 58% | 2461 fps | 97.4% |
| Ramshot Magnum | <<locked>> | 92% | 36,709 psi | 58% | 2470 fps | 95.5% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,731 psi | 43% | 1558 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 48,776 psi | 76% | 2602 fps | 99.3% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 45,542 psi | 71% | 2648 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 38,522 psi | 60% | 2493 fps | 98.9% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 37,318 psi | 58% | 2503 fps | 98.5% |
| ReloadSwiss RS 76 | <<locked>> | 92% | 33,982 psi | 53% | 2474 fps | 95% |
| Rottweil R 902 | <<locked>> | 80% | 51,880 psi | 81% | 2608 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 45,527 psi | 71% | 2556 fps | 100% |
| Rottweil R 904 | <<locked>> | 88% | 44,454 psi | 70% | 2549 fps | 95.7% |
| Rottweil R 905 | <<locked>> | 86% | 38,928 psi | 61% | 2493 fps | 95.5% |
| Rottweil R 907 | <<locked>> | 80% | 42,467 psi | 67% | 2490 fps | 97.4% |
| Shooters World Long Rifle | <<locked>> | 80% | 41,394 psi | 65% | 2470 fps | 98.7% |
| Shooters World Precision | <<locked>> | 80% | 50,154 psi | 79% | 2598 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 39,566 psi | 62% | 2454 fps | 97.4% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 46,963 psi | 74% | 2608 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 46,746 psi | 73% | 2461 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 40,451 psi | 63% | 2418 fps | 97.5% |
| SNPE Vectan Tubal 8000 | <<locked>> | 86% | 38,566 psi | 60% | 2487 fps | 95.4% |
| Somchem S355 | <<locked>> | 80% | 45,890 psi | 72% | 2552 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 45,513 psi | 71% | 2539 fps | 95.1% |
| Somchem S365 | <<locked>> | 80% | 34,824 psi | 55% | 2431 fps | 100% |
| Somchem S385 | <<locked>> | 84% | 36,883 psi | 58% | 2425 fps | 95.8% |
| Vihtavuori N135 | <<locked>> | 80% | 52,272 psi | 82% | 2569 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 52,533 psi | 82% | 2582 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 43,787 psi | 69% | 2484 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 39,842 psi | 62% | 2470 fps | 99.2% |
| Vihtavuori N165 | <<locked>> | 88% | 36,448 psi | 57% | 2405 fps | 95.2% |
| Vihtavuori N540 | <<locked>> | 80% | 50,865 psi | 80% | 2579 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 39,262 psi | 62% | 2470 fps | 99% |
| Vihtavuori N555 | <<locked>> | 80% | 30,226 psi | 47% | 2323 fps | 97.4% |
| Vihtavuori N560 | 82.6 gr | 92% | 45,730 psi | 72% | 2674 fps | 95.6% |
| Vihtavuori N565 | <<locked>> | 98% | 45,005 psi | 71% | 2648 fps | 95.7% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 38,957 psi | 61% | 2438 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 40,712 psi | 64% | 2523 fps | 97.5% |
| Winchester StaBALL HD | <<locked>> | 80% | 24,018 psi | 38% | 2224 fps | 96.3% |
| Winchester Supreme 780 | <<locked>> | 88% | 38,899 psi | 61% | 2461 fps | 95.3% |
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 .338 Rem. Ultra Mag. loaded with the .338 | 225gr | Hornady GMX. Norma MRP delivers the highest muzzle velocity at 2,858 fps; across all powders the maximum-charge window runs from 1,699 fps to 2,858 fps. Accurate 3100 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 225.0 gr projectile in 0.338" calls for a 1:12.0 twist; slower twists will usually not stabilise this weight. Accurate 3100, ADI AR 2213, 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. Alliant Reloder-26, Norma MRP, Vihtavuori N560 rank at the top here: for .338 Rem. Ultra Mag. with the .338 | 225gr | Hornady GMX 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.