Load Specifications
Load data in caliber .338 Rem. Ultra Mag. with .338 | 250gr | Lapua Lock Base bullet and 79 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 Winchester StaBALL HD.
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: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 96% | 57,566 psi | 90% | 2631 fps | 100% |
| Accurate 4350 | <<locked>> | 86% | 55,303 psi | 87% | 2618 fps | 100% |
| Accurate High Country | <<locked>> | 92% | 55,201 psi | 87% | 2726 fps | 99.2% |
| Accurate MAGPRO | <<locked>> | 94% | 56,202 psi | 88% | 2726 fps | 98.5% |
| ADI AR 2208 | <<locked>> | 82% | 56,333 psi | 88% | 2575 fps | 100% |
| ADI AR 2209 | <<locked>> | 92% | 56,144 psi | 88% | 2671 fps | 99.7% |
| ADI AR 2213 | <<locked>> | 96% | 57,638 psi | 90% | 2730 fps | 99.4% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 48,167 psi | 75% | 2579 fps | 98.3% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 42,960 psi | 67% | 2546 fps | 99.6% |
| Alliant Power Pro Varmint | <<locked>> | 92% | 56,260 psi | 88% | 2667 fps | 99.7% |
| Alliant Power Pro Varmint | <<locked>> | 92% | 56,260 psi | 88% | 2667 fps | 99.7% |
| Alliant Reloder-16 | <<locked>> | 88% | 56,043 psi | 88% | 2664 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 84% | 57,435 psi | 90% | 2680 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 92% | 55,564 psi | 87% | 2661 fps | 99.7% |
| Alliant Reloder-22 | <<locked>> | 96% | 57,508 psi | 90% | 2723 fps | 99.9% |
| Alliant Reloder-23 | <<locked>> | 96% | 54,868 psi | 86% | 2644 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 54,099 psi | 85% | 2697 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 92% | 55,172 psi | 86% | 2726 fps | 100% |
| Baschieri & Pellagri 109 | <<locked>> | 96% | 55,666 psi | 87% | 2635 fps | 96.7% |
| Bofors RP15 | <<locked>> | 98% | 56,434 psi | 88% | 2707 fps | 99.8% |
| Bofors RP30ᴾ | <<locked>> | 100% | 50,198 psi | 79% | 2648 fps | 98.9% |
| Bofors RP5 | <<locked>> | 96% | 57,508 psi | 90% | 2723 fps | 99.9% |
| Bofors RP7 | <<locked>> | 84% | 54,375 psi | 85% | 2572 fps | 99.9% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 53,026 psi | 83% | 2657 fps | 99.4% |
| Hodgdon H414 | <<locked>> | 86% | 57,043 psi | 89% | 2667 fps | 100% |
| Hodgdon H4350 | <<locked>> | 84% | 55,999 psi | 88% | 2625 fps | 99.8% |
| Hodgdon H4831 | <<locked>> | 94% | 57,508 psi | 90% | 2667 fps | 98.9% |
| Hodgdon H4831 SC | <<locked>> | 94% | 56,420 psi | 88% | 2654 fps | 98.7% |
| Hodgdon Hybrid 100V | <<locked>> | 90% | 56,347 psi | 88% | 2592 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 53,098 psi | 83% | 2762 fps | 100% |
| Hodgdon Superformance | <<locked>> | 86% | 57,711 psi | 90% | 2703 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,072 psi | 58% | 1634 fps | 100% |
| IMR 4350 | <<locked>> | 88% | 55,680 psi | 87% | 2602 fps | 99.9% |
| IMR 4451 Enduron | <<locked>> | 84% | 55,622 psi | 87% | 2589 fps | 100% |
| IMR 4831 | <<locked>> | 88% | 55,753 psi | 87% | 2608 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 92% | 55,042 psi | 86% | 2605 fps | 98.6% |
| IMR 7828 SSC | <<locked>> | 96% | 55,259 psi | 87% | 2707 fps | 99.2% |
| Lovex S065 | <<locked>> | 86% | 56,217 psi | 88% | 2585 fps | 100% |
| Lovex S070 | <<locked>> | 86% | 54,563 psi | 86% | 2585 fps | 100% |
| Lovex S071ᴾ | <<locked>> | 100% | 54,984 psi | 86% | 2602 fps | 100% |
| Norma 204 | <<locked>> | 88% | 56,768 psi | 89% | 2657 fps | 99.7% |
| Norma 217ᴾ | <<locked>> | 100% | 38,435 psi | 60% | 2480 fps | 98.2% |
| Norma MRP | <<locked>> | 94% | 57,377 psi | 90% | 2743 fps | 100% |
| Norma URP | <<locked>> | 88% | 57,334 psi | 90% | 2648 fps | 100% |
| Ramshot Grand | <<locked>> | 96% | 56,072 psi | 88% | 2726 fps | 99.5% |
| Ramshot Hunter | <<locked>> | 88% | 56,231 psi | 88% | 2657 fps | 100% |
| Ramshot Magnum | <<locked>> | 98% | 54,201 psi | 85% | 2661 fps | 99.9% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,927 psi | 59% | 1673 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 82% | 56,884 psi | 89% | 2664 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 86% | 55,201 psi | 87% | 2638 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 88% | 57,406 psi | 90% | 2713 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 53,679 psi | 84% | 2759 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 48,602 psi | 76% | 2654 fps | 97.4% |
| Rottweil R 903 | <<locked>> | 82% | 55,608 psi | 87% | 2569 fps | 100% |
| Rottweil R 904 | <<locked>> | 92% | 57,406 psi | 90% | 2641 fps | 99.3% |
| Rottweil R 905 | <<locked>> | 92% | 55,085 psi | 86% | 2648 fps | 99.7% |
| Rottweil R 907 | <<locked>> | 84% | 54,375 psi | 85% | 2572 fps | 99.9% |
| Shooters World Long Rifle | <<locked>> | 86% | 56,217 psi | 88% | 2585 fps | 100% |
| Shooters World SW4350 | <<locked>> | 86% | 54,563 psi | 86% | 2585 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 82% | 56,942 psi | 89% | 2621 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 82% | 55,390 psi | 87% | 2448 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 55,651 psi | 87% | 2546 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 92% | 54,650 psi | 86% | 2648 fps | 99.7% |
| Somchem S355 | <<locked>> | 82% | 55,245 psi | 87% | 2562 fps | 100% |
| Somchem S361 | <<locked>> | 90% | 55,216 psi | 87% | 2585 fps | 98.5% |
| Somchem S365 | <<locked>> | 88% | 53,969 psi | 85% | 2602 fps | 100% |
| Somchem S385 | <<locked>> | 92% | 55,608 psi | 87% | 2625 fps | 99.9% |
| Vihtavuori N150 | <<locked>> | 84% | 56,391 psi | 88% | 2536 fps | 100% |
| Vihtavuori N160 | <<locked>> | 86% | 55,593 psi | 87% | 2592 fps | 100% |
| Vihtavuori N165 | <<locked>> | 96% | 54,984 psi | 86% | 2605 fps | 99.8% |
| Vihtavuori N550 | <<locked>> | 86% | 54,839 psi | 86% | 2602 fps | 100% |
| Vihtavuori N555 | <<locked>> | 94% | 57,087 psi | 89% | 2667 fps | 100% |
| Vihtavuori N560 | <<locked>> | 94% | 57,217 psi | 90% | 2740 fps | 99.1% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 56,898 psi | 89% | 2720 fps | 99.2% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 49,777 psi | 78% | 2661 fps | 97.1% |
| Winchester 6.5 StaBALL | <<locked>> | 86% | 55,042 psi | 86% | 2556 fps | 100% |
| Winchester 760 | <<locked>> | 86% | 57,246 psi | 90% | 2671 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 98% | 56,188 psi | 88% | 2766 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 94% | 55,579 psi | 87% | 2621 fps | 99.6% |
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 3100 | <<locked>> | 80% | 33,605 psi | 53% | 2244 fps | 97.7% |
| Accurate 4350 | <<locked>> | 80% | 45,092 psi | 71% | 2470 fps | 100% |
| Accurate High Country | 75.6 gr | 82% | 38,943 psi | 61% | 2444 fps | 95.7% |
| Accurate MAGPRO | <<locked>> | 86% | 42,366 psi | 66% | 2503 fps | 95.4% |
| ADI AR 2208 | <<locked>> | 80% | 52,997 psi | 83% | 2533 fps | 100% |
| ADI AR 2209 | <<locked>> | 80% | 37,608 psi | 59% | 2359 fps | 96.3% |
| ADI AR 2213 | <<locked>> | 84% | 38,334 psi | 60% | 2398 fps | 95.1% |
| ADI AR 2217 | <<locked>> | 94% | 39,494 psi | 62% | 2418 fps | 95.8% |
| ADI AR 2225 | <<locked>> | 90% | 31,125 psi | 49% | 2277 fps | 95.7% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 37,985 psi | 60% | 2362 fps | 96.5% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 37,985 psi | 60% | 2362 fps | 96.5% |
| Alliant Reloder-16 | <<locked>> | 80% | 43,250 psi | 68% | 2477 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 80% | 49,922 psi | 78% | 2582 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 37,637 psi | 59% | 2356 fps | 96.4% |
| Alliant Reloder-22 | <<locked>> | 80% | 33,518 psi | 53% | 2303 fps | 95% |
| Alliant Reloder-23 | <<locked>> | 80% | 32,285 psi | 51% | 2274 fps | 99.8% |
| Alliant Reloder-25 | <<locked>> | 80% | 28,123 psi | 44% | 2188 fps | 96.1% |
| Alliant Reloder-26 | 76 gr | 80% | 35,128 psi | 55% | 2395 fps | 99.3% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 49,240 psi | 77% | 2533 fps | 95.1% |
| Bofors RP15 | <<locked>> | 84% | 35,592 psi | 56% | 2349 fps | 95.7% |
| Bofors RP30 | <<locked>> | 90% | 35,650 psi | 56% | 2379 fps | 95% |
| Bofors RP5 | <<locked>> | 80% | 33,518 psi | 53% | 2303 fps | 95% |
| Bofors RP7 | <<locked>> | 80% | 47,906 psi | 75% | 2474 fps | 99.3% |
| Hodgdon H1000 | <<locked>> | 90% | 37,768 psi | 59% | 2385 fps | 95.9% |
| Hodgdon H414 | <<locked>> | 80% | 46,673 psi | 73% | 2513 fps | 99.5% |
| Hodgdon H4350 | <<locked>> | 80% | 49,356 psi | 77% | 2530 fps | 99.1% |
| Hodgdon H4831 | <<locked>> | 84% | 40,959 psi | 64% | 2405 fps | 95.4% |
| Hodgdon H4831 SC | <<locked>> | 84% | 40,205 psi | 63% | 2392 fps | 95.1% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 40,770 psi | 64% | 2372 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 86% | 33,359 psi | 52% | 2365 fps | 95.4% |
| Hodgdon Superformance | <<locked>> | 80% | 46,238 psi | 72% | 2539 fps | 99.4% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,702 psi | 43% | 1460 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 43,337 psi | 68% | 2411 fps | 98.7% |
| IMR 4451 Enduron | <<locked>> | 80% | 49,313 psi | 77% | 2497 fps | 99.7% |
| IMR 4831 | <<locked>> | 80% | 42,873 psi | 67% | 2421 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 82% | 40,161 psi | 63% | 2356 fps | 95.3% |
| IMR 7828 SSC | <<locked>> | 86% | 39,407 psi | 62% | 2431 fps | 95.6% |
| Lovex S065 | <<locked>> | 80% | 46,891 psi | 73% | 2451 fps | 99.9% |
| Lovex S070 | <<locked>> | 80% | 45,092 psi | 71% | 2441 fps | 99.4% |
| Lovex S071 | <<locked>> | 80% | 29,008 psi | 45% | 2139 fps | 95.9% |
| Norma 204 | <<locked>> | 80% | 43,279 psi | 68% | 2448 fps | 97.8% |
| Norma 217 | <<locked>> | 94% | 31,546 psi | 49% | 2320 fps | 95.5% |
| Norma MRP | <<locked>> | 80% | 34,998 psi | 55% | 2362 fps | 97.1% |
| Norma URP | <<locked>> | 80% | 44,222 psi | 69% | 2457 fps | 100% |
| Ramshot Grand | <<locked>> | 86% | 39,015 psi | 61% | 2438 fps | 96% |
| Ramshot Hunter | <<locked>> | 80% | 43,091 psi | 68% | 2457 fps | 99.5% |
| Ramshot Magnum | <<locked>> | 84% | 32,387 psi | 51% | 2274 fps | 95.4% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,384 psi | 44% | 1496 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 53,040 psi | 83% | 2618 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 45,020 psi | 71% | 2490 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 43,178 psi | 68% | 2507 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 84% | 30,356 psi | 48% | 2283 fps | 95.1% |
| ReloadSwiss RS 80 | <<locked>> | 96% | 41,727 psi | 65% | 2533 fps | 95.5% |
| Rottweil R 903 | <<locked>> | 80% | 52,040 psi | 82% | 2523 fps | 100% |
| Rottweil R 904 | <<locked>> | 80% | 39,030 psi | 61% | 2343 fps | 95.6% |
| Rottweil R 905 | <<locked>> | 80% | 36,999 psi | 58% | 2343 fps | 96.4% |
| Rottweil R 907 | <<locked>> | 80% | 47,906 psi | 75% | 2474 fps | 99.3% |
| Shooters World Long Rifle | <<locked>> | 80% | 46,891 psi | 73% | 2451 fps | 99.9% |
| Shooters World SW4350 | <<locked>> | 80% | 45,092 psi | 71% | 2441 fps | 99.4% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 53,388 psi | 84% | 2575 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 52,228 psi | 82% | 2411 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 45,876 psi | 72% | 2405 fps | 99.4% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 36,680 psi | 57% | 2336 fps | 96.2% |
| Somchem S355 | <<locked>> | 80% | 51,967 psi | 81% | 2520 fps | 100% |
| Somchem S361 | <<locked>> | 82% | 42,409 psi | 66% | 2382 fps | 95.8% |
| Somchem S365 | <<locked>> | 80% | 41,191 psi | 65% | 2421 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 37,594 psi | 59% | 2326 fps | 97.4% |
| Vihtavuori N150 | <<locked>> | 80% | 49,617 psi | 78% | 2448 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 45,672 psi | 72% | 2454 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 32,489 psi | 51% | 2215 fps | 95.2% |
| Vihtavuori N550 | <<locked>> | 80% | 45,005 psi | 71% | 2457 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 36,143 psi | 57% | 2339 fps | 99.7% |
| Vihtavuori N560 | <<locked>> | 84% | 40,538 psi | 64% | 2464 fps | 95.5% |
| Vihtavuori N565 | <<locked>> | 90% | 40,480 psi | 63% | 2454 fps | 95.9% |
| Vihtavuori N568 | <<locked>> | 96% | 43,250 psi | 68% | 2546 fps | 95.3% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 44,759 psi | 70% | 2418 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 46,847 psi | 73% | 2516 fps | 99.5% |
| Winchester StaBALL HD | 73 gr | 80% | 28,616 psi | 45% | 2287 fps | 99.9% |
| Winchester Supreme 780 | <<locked>> | 80% | 34,185 psi | 54% | 2257 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 79 powders for .338 Rem. Ultra Mag. loaded with the .338 | 250gr | Lapua Lock Base. Winchester StaBALL HD delivers the highest muzzle velocity at 2,766 fps; across all powders the maximum-charge window runs from 1,634 fps to 2,766 fps. ADI AR 2217 gives the best case fill at 100 %, and 79 of the 79 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 58–90 %, leaving at least 10 % headroom. The 250.0 gr projectile in 0.338" calls for a 1:13.5 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2225, Alliant Reloder-25 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, Winchester StaBALL HD rank at the top here: for .338 Rem. Ultra Mag. with the .338 | 250gr | Lapua Lock Base 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.