Load Specifications
Load data in caliber .338 Rem. Ultra Mag. with .338 | 250gr | Rhino Penetrator bullet and 82 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Vihtavuori N560, Norma MRP and Accurate MAGPRO.
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% | 55,985 psi | 88% | 2608 fps | 100% |
| Accurate 4350 | <<locked>> | 88% | 57,580 psi | 90% | 2638 fps | 100% |
| Accurate High Country | <<locked>> | 94% | 57,435 psi | 90% | 2749 fps | 99.4% |
| Accurate MAGPRO | <<locked>> | 94% | 54,259 psi | 85% | 2694 fps | 98.1% |
| ADI AR 2208 | <<locked>> | 82% | 55,158 psi | 86% | 2552 fps | 100% |
| ADI AR 2209 | <<locked>> | 92% | 54,520 psi | 85% | 2641 fps | 99.5% |
| ADI AR 2213 | <<locked>> | 96% | 55,956 psi | 88% | 2697 fps | 99.1% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 46,789 psi | 73% | 2546 fps | 97.8% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 41,568 psi | 65% | 2513 fps | 99.3% |
| Alliant Power Pro Varmint | <<locked>> | 92% | 54,694 psi | 86% | 2638 fps | 99.5% |
| Alliant Reloder- TS 15.5 | <<locked>> | 82% | 56,565 psi | 89% | 2575 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 88% | 54,592 psi | 86% | 2641 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 84% | 55,767 psi | 87% | 2654 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 94% | 57,566 psi | 90% | 2677 fps | 99.7% |
| Alliant Reloder-22 | <<locked>> | 96% | 55,753 psi | 87% | 2690 fps | 99.7% |
| Alliant Reloder-23 | <<locked>> | 98% | 56,608 psi | 89% | 2657 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 52,228 psi | 82% | 2667 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 94% | 57,290 psi | 90% | 2746 fps | 100% |
| Baschieri & Pellagri 109 | <<locked>> | 96% | 54,520 psi | 85% | 2608 fps | 96.2% |
| Bofors RP15 | <<locked>> | 98% | 54,708 psi | 86% | 2677 fps | 99.6% |
| Bofors RP3 | <<locked>> | 82% | 57,624 psi | 90% | 2589 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 48,283 psi | 76% | 2612 fps | 98.5% |
| Bofors RP5 | <<locked>> | 96% | 55,753 psi | 87% | 2690 fps | 99.7% |
| Bofors RP7 | <<locked>> | 86% | 56,521 psi | 89% | 2592 fps | 99.9% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 51,387 psi | 81% | 2625 fps | 99.1% |
| Hodgdon H380 | <<locked>> | 82% | 57,508 psi | 90% | 2608 fps | 100% |
| Hodgdon H414 | <<locked>> | 86% | 55,550 psi | 87% | 2641 fps | 100% |
| Hodgdon H4350 | <<locked>> | 84% | 54,737 psi | 86% | 2598 fps | 99.6% |
| Hodgdon H4831 | <<locked>> | 94% | 55,811 psi | 87% | 2638 fps | 98.5% |
| Hodgdon H4831 SC | <<locked>> | 94% | 54,752 psi | 86% | 2621 fps | 98.3% |
| Hodgdon Hybrid 100V | <<locked>> | 90% | 55,013 psi | 86% | 2569 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 51,300 psi | 80% | 2726 fps | 99.9% |
| Hodgdon Superformance | <<locked>> | 86% | 55,912 psi | 88% | 2674 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,927 psi | 58% | 1621 fps | 100% |
| IMR 4350 | <<locked>> | 88% | 54,534 psi | 85% | 2579 fps | 99.8% |
| IMR 4451 Enduron | <<locked>> | 84% | 54,563 psi | 86% | 2566 fps | 99.9% |
| IMR 4831 | <<locked>> | 88% | 54,215 psi | 85% | 2582 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 94% | 57,058 psi | 89% | 2621 fps | 98.7% |
| IMR 7828 SSC | <<locked>> | 98% | 57,246 psi | 90% | 2723 fps | 99.3% |
| Lovex S065 | <<locked>> | 86% | 54,969 psi | 86% | 2562 fps | 100% |
| Lovex S070 | <<locked>> | 88% | 56,478 psi | 89% | 2605 fps | 100% |
| Lovex S071ᴾ | <<locked>> | 100% | 53,229 psi | 83% | 2572 fps | 100% |
| Norma 204 | <<locked>> | 88% | 55,216 psi | 87% | 2628 fps | 99.4% |
| Norma 217ᴾ | <<locked>> | 100% | 37,057 psi | 58% | 2444 fps | 97.6% |
| Norma MRP | <<locked>> | 94% | 55,579 psi | 87% | 2713 fps | 100% |
| Norma URP | <<locked>> | 88% | 55,753 psi | 87% | 2621 fps | 100% |
| Ramshot Grand | <<locked>> | 96% | 54,085 psi | 85% | 2687 fps | 99.2% |
| Ramshot Hunter | <<locked>> | 88% | 54,592 psi | 86% | 2628 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 56,478 psi | 89% | 2684 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,782 psi | 59% | 1663 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 57,174 psi | 90% | 2598 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 82% | 55,274 psi | 87% | 2641 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 57,508 psi | 90% | 2661 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 88% | 55,666 psi | 87% | 2687 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 51,837 psi | 81% | 2726 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 46,659 psi | 73% | 2615 fps | 96.8% |
| Rottweil R 903 | <<locked>> | 84% | 57,696 psi | 90% | 2589 fps | 100% |
| Rottweil R 904 | <<locked>> | 92% | 55,912 psi | 88% | 2612 fps | 99% |
| Rottweil R 905 | <<locked>> | 94% | 57,087 psi | 89% | 2671 fps | 99.8% |
| Rottweil R 907 | <<locked>> | 86% | 56,521 psi | 89% | 2592 fps | 99.9% |
| Shooters World Long Rifle | <<locked>> | 86% | 54,969 psi | 86% | 2562 fps | 100% |
| Shooters World SW4350 | <<locked>> | 88% | 56,478 psi | 89% | 2605 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 82% | 55,593 psi | 87% | 2595 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 57,740 psi | 90% | 2467 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 54,317 psi | 85% | 2520 fps | 99.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 56,637 psi | 89% | 2664 fps | 99.7% |
| Somchem S355 | <<locked>> | 84% | 57,493 psi | 90% | 2582 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 57,580 psi | 90% | 2605 fps | 98.7% |
| Somchem S365 | <<locked>> | 90% | 56,115 psi | 88% | 2625 fps | 100% |
| Somchem S385 | <<locked>> | 94% | 57,638 psi | 90% | 2644 fps | 100% |
| Vihtavuori N150 | <<locked>> | 84% | 55,027 psi | 86% | 2510 fps | 100% |
| Vihtavuori N160 | <<locked>> | 86% | 54,056 psi | 85% | 2566 fps | 100% |
| Vihtavuori N165 | <<locked>> | 98% | 57,145 psi | 90% | 2625 fps | 99.9% |
| Vihtavuori N550 | <<locked>> | 88% | 56,855 psi | 89% | 2621 fps | 100% |
| Vihtavuori N555 | <<locked>> | 94% | 55,550 psi | 87% | 2641 fps | 100% |
| Vihtavuori N560 | <<locked>> | 94% | 55,477 psi | 87% | 2707 fps | 98.7% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 54,868 psi | 86% | 2684 fps | 98.8% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 47,935 psi | 75% | 2621 fps | 96.5% |
| Winchester 6.5 StaBALL | <<locked>> | 88% | 57,261 psi | 90% | 2575 fps | 100% |
| Winchester 760 | <<locked>> | 86% | 55,767 psi | 87% | 2644 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 98% | 53,737 psi | 84% | 2736 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 96% | 57,653 psi | 90% | 2638 fps | 99.7% |
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% | 32,605 psi | 51% | 2218 fps | 97.2% |
| Accurate 4350 | <<locked>> | 80% | 43,859 psi | 69% | 2444 fps | 100% |
| Accurate High Country | <<locked>> | 82% | 37,739 psi | 59% | 2415 fps | 95.1% |
| Accurate MAGPRO | 80.5 gr | 88% | 43,903 psi | 69% | 2523 fps | 95.7% |
| ADI AR 2208 | <<locked>> | 80% | 51,996 psi | 81% | 2510 fps | 100% |
| ADI AR 2209 | <<locked>> | 80% | 36,637 psi | 57% | 2329 fps | 95.8% |
| ADI AR 2213 | <<locked>> | 86% | 40,001 psi | 63% | 2425 fps | 95.5% |
| ADI AR 2217 | <<locked>> | 94% | 38,377 psi | 60% | 2385 fps | 95.1% |
| ADI AR 2225 | <<locked>> | 92% | 32,097 psi | 50% | 2297 fps | 96% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 36,985 psi | 58% | 2333 fps | 95.9% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 53,127 psi | 83% | 2530 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 42,032 psi | 66% | 2451 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 80% | 48,472 psi | 76% | 2556 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 36,637 psi | 57% | 2329 fps | 95.9% |
| Alliant Reloder-22 | <<locked>> | 82% | 34,766 psi | 54% | 2326 fps | 95.3% |
| Alliant Reloder-23 | <<locked>> | 80% | 31,285 psi | 49% | 2244 fps | 99.6% |
| Alliant Reloder-25 | <<locked>> | 80% | 27,340 psi | 43% | 2159 fps | 95.4% |
| Alliant Reloder-26 | <<locked>> | 80% | 33,823 psi | 53% | 2362 fps | 98.9% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 51,126 psi | 80% | 2556 fps | 95.4% |
| Bofors RP15 | <<locked>> | 84% | 34,490 psi | 54% | 2316 fps | 95% |
| Bofors RP3 | <<locked>> | 80% | 53,853 psi | 84% | 2543 fps | 100% |
| Bofors RP30 | <<locked>> | 92% | 36,825 psi | 58% | 2398 fps | 95.3% |
| Bofors RP5 | <<locked>> | 82% | 34,766 psi | 54% | 2326 fps | 95.3% |
| Bofors RP7 | <<locked>> | 80% | 46,789 psi | 73% | 2448 fps | 99.1% |
| Hodgdon H1000 | <<locked>> | 90% | 36,753 psi | 58% | 2352 fps | 95.2% |
| Hodgdon H380 | <<locked>> | 80% | 53,983 psi | 85% | 2562 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 45,542 psi | 71% | 2490 fps | 99.3% |
| Hodgdon H4350 | <<locked>> | 80% | 48,080 psi | 75% | 2500 fps | 98.9% |
| Hodgdon H4831 | <<locked>> | 86% | 42,569 psi | 67% | 2428 fps | 95.7% |
| Hodgdon H4831 SC | <<locked>> | 86% | 41,930 psi | 66% | 2415 fps | 95.5% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 39,566 psi | 62% | 2346 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 88% | 34,577 psi | 54% | 2388 fps | 95.8% |
| Hodgdon Superformance | <<locked>> | 80% | 44,860 psi | 70% | 2510 fps | 99.1% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,644 psi | 43% | 1450 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 42,308 psi | 66% | 2388 fps | 98.4% |
| IMR 4451 Enduron | <<locked>> | 80% | 48,240 psi | 76% | 2470 fps | 99.5% |
| IMR 4831 | <<locked>> | 80% | 41,713 psi | 65% | 2395 fps | 99.9% |
| IMR 4955 Enduron | <<locked>> | 84% | 41,669 psi | 65% | 2379 fps | 95.6% |
| IMR 7828 SSC | <<locked>> | 86% | 38,348 psi | 60% | 2402 fps | 95% |
| Lovex S065 | <<locked>> | 80% | 45,759 psi | 72% | 2425 fps | 99.8% |
| Lovex S070 | <<locked>> | 80% | 43,990 psi | 69% | 2415 fps | 99.2% |
| Lovex S071 | <<locked>> | 80% | 28,036 psi | 44% | 2110 fps | 95.3% |
| Norma 204 | <<locked>> | 80% | 42,076 psi | 66% | 2418 fps | 97.3% |
| Norma 217 | <<locked>> | 96% | 32,518 psi | 51% | 2336 fps | 95.7% |
| Norma MRP | 71.9 gr | 80% | 33,881 psi | 53% | 2333 fps | 96.5% |
| Norma URP | <<locked>> | 80% | 43,033 psi | 67% | 2434 fps | 100% |
| Ramshot Grand | <<locked>> | 86% | 37,840 psi | 59% | 2405 fps | 95.2% |
| Ramshot Hunter | <<locked>> | 80% | 41,843 psi | 66% | 2428 fps | 99.3% |
| Ramshot Magnum | <<locked>> | 86% | 33,808 psi | 53% | 2300 fps | 95.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,326 psi | 44% | 1486 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 53,751 psi | 84% | 2552 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 51,445 psi | 81% | 2595 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 43,700 psi | 68% | 2464 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 41,959 psi | 66% | 2477 fps | 99.9% |
| ReloadSwiss RS 76 | <<locked>> | 86% | 31,488 psi | 49% | 2306 fps | 95.5% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 43,236 psi | 68% | 2552 fps | 95.7% |
| Rottweil R 903 | <<locked>> | 80% | 50,749 psi | 80% | 2497 fps | 100% |
| Rottweil R 904 | <<locked>> | 80% | 38,029 psi | 60% | 2313 fps | 95% |
| Rottweil R 905 | <<locked>> | 80% | 35,940 psi | 56% | 2316 fps | 95.8% |
| Rottweil R 907 | <<locked>> | 80% | 46,789 psi | 73% | 2448 fps | 99.1% |
| Shooters World Long Rifle | <<locked>> | 80% | 45,759 psi | 72% | 2425 fps | 99.8% |
| Shooters World SW4350 | <<locked>> | 80% | 43,990 psi | 69% | 2415 fps | 99.2% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 51,996 psi | 81% | 2549 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 51,010 psi | 80% | 2388 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 44,686 psi | 70% | 2379 fps | 99.2% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 35,607 psi | 56% | 2310 fps | 95.7% |
| Somchem S355 | <<locked>> | 80% | 50,720 psi | 79% | 2497 fps | 100% |
| Somchem S361 | <<locked>> | 82% | 41,307 psi | 65% | 2352 fps | 95.2% |
| Somchem S365 | <<locked>> | 80% | 39,914 psi | 63% | 2395 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 36,448 psi | 57% | 2300 fps | 96.9% |
| Vihtavuori N150 | <<locked>> | 80% | 48,443 psi | 76% | 2425 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 44,527 psi | 70% | 2428 fps | 100% |
| Vihtavuori N165 | <<locked>> | 82% | 33,707 psi | 53% | 2234 fps | 95.5% |
| Vihtavuori N550 | <<locked>> | 80% | 43,947 psi | 69% | 2431 fps | 99.9% |
| Vihtavuori N555 | <<locked>> | 80% | 34,998 psi | 55% | 2310 fps | 99.5% |
| Vihtavuori N560 | 77.3 gr | 86% | 42,090 psi | 66% | 2487 fps | 95.8% |
| Vihtavuori N565 | <<locked>> | 90% | 39,102 psi | 61% | 2418 fps | 95.2% |
| Vihtavuori N568 | <<locked>> | 98% | 44,715 psi | 70% | 2566 fps | 95.5% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 43,439 psi | 68% | 2392 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 45,701 psi | 72% | 2490 fps | 99.3% |
| Winchester StaBALL HD | <<locked>> | 80% | 27,688 psi | 43% | 2254 fps | 99.7% |
| Winchester Supreme 780 | <<locked>> | 82% | 35,578 psi | 56% | 2280 fps | 95.5% |
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 82 powders for .338 Rem. Ultra Mag. loaded with the .338 | 250gr | Rhino Penetrator. Accurate High Country delivers the highest muzzle velocity at 2,749 fps; across all powders the maximum-charge window runs from 1,621 fps to 2,749 fps. ADI AR 2217 gives the best case fill at 100 %, and 82 of the 82 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 1:13.0 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. Vihtavuori N560, Norma MRP, Accurate MAGPRO rank at the top here: for .338 Rem. Ultra Mag. with the .338 | 250gr | Rhino Penetrator 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.