Load Specifications
Load data in caliber .338 Rem. Ultra Mag. with .338 | 300gr | Hornady HPBT bullet and 76 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 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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Max Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 92% | 54,882 psi | 86% | 2375 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 56,202 psi | 88% | 2392 fps | 100% |
| Accurate High Country | <<locked>> | 90% | 56,463 psi | 88% | 2513 fps | 99.9% |
| Accurate MAGPRO | <<locked>> | 92% | 57,217 psi | 90% | 2516 fps | 99.6% |
| ADI AR 2209 | <<locked>> | 90% | 56,710 psi | 89% | 2448 fps | 100% |
| ADI AR 2213 | <<locked>> | 92% | 54,491 psi | 85% | 2461 fps | 99.8% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 52,344 psi | 82% | 2431 fps | 99.8% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 46,934 psi | 74% | 2408 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 90% | 57,087 psi | 89% | 2448 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 90% | 57,087 psi | 89% | 2448 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 86% | 57,174 psi | 90% | 2438 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 90% | 56,405 psi | 88% | 2441 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 92% | 54,708 psi | 86% | 2457 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 94% | 56,260 psi | 88% | 2421 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 98% | 55,463 psi | 87% | 2480 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 90% | 56,768 psi | 89% | 2507 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 48,805 psi | 76% | 2454 fps | 97.1% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 55,869 psi | 88% | 2431 fps | 98.3% |
| Bofors RP15 | <<locked>> | 96% | 57,624 psi | 90% | 2493 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 55,143 psi | 86% | 2493 fps | 100% |
| Bofors RP5 | <<locked>> | 92% | 54,708 psi | 86% | 2457 fps | 100% |
| Bofors RP7 | <<locked>> | 82% | 54,592 psi | 86% | 2346 fps | 100% |
| Hodgdon H1000 | <<locked>> | 98% | 54,041 psi | 85% | 2454 fps | 100% |
| Hodgdon H414 | <<locked>> | 84% | 57,667 psi | 90% | 2441 fps | 100% |
| Hodgdon H4350 | <<locked>> | 82% | 56,536 psi | 89% | 2405 fps | 100% |
| Hodgdon H4831 | <<locked>> | 90% | 54,505 psi | 85% | 2408 fps | 99.5% |
| Hodgdon H4831 SC | <<locked>> | 92% | 56,913 psi | 89% | 2438 fps | 99.7% |
| Hodgdon Hybrid 100V | <<locked>> | 88% | 57,276 psi | 90% | 2365 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 54,375 psi | 85% | 2552 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 54,157 psi | 85% | 2428 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,449 psi | 59% | 1480 fps | 100% |
| IMR 4350 | <<locked>> | 86% | 56,101 psi | 88% | 2382 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 82% | 55,840 psi | 88% | 2362 fps | 100% |
| IMR 4831 | <<locked>> | 86% | 56,449 psi | 88% | 2385 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 55,245 psi | 87% | 2388 fps | 99.6% |
| IMR 7828 SSC | <<locked>> | 94% | 56,362 psi | 88% | 2493 fps | 99.9% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 42,453 psi | 67% | 2333 fps | 98.7% |
| Lovex S065 | <<locked>> | 84% | 56,753 psi | 89% | 2362 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 54,911 psi | 86% | 2362 fps | 100% |
| Lovex S071 | <<locked>> | 98% | 56,231 psi | 88% | 2388 fps | 100% |
| Norma 204 | <<locked>> | 86% | 57,348 psi | 90% | 2438 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 42,830 psi | 67% | 2356 fps | 99.9% |
| Norma MRP | <<locked>> | 90% | 54,665 psi | 86% | 2474 fps | 100% |
| Norma URP | <<locked>> | 84% | 54,447 psi | 85% | 2375 fps | 100% |
| Ramshot Grand | <<locked>> | 94% | 57,348 psi | 90% | 2513 fps | 100% |
| Ramshot Hunter | <<locked>> | 86% | 56,956 psi | 89% | 2431 fps | 100% |
| Ramshot Magnum | <<locked>> | 96% | 55,361 psi | 87% | 2451 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,261 psi | 60% | 1512 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 56,072 psi | 88% | 2415 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 84% | 54,360 psi | 85% | 2438 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 55,013 psi | 86% | 2549 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 53,998 psi | 85% | 2520 fps | 99.5% |
| Rottweil R 904 | <<locked>> | 88% | 54,375 psi | 85% | 2379 fps | 99.7% |
| Rottweil R 905 | <<locked>> | 90% | 55,970 psi | 88% | 2431 fps | 100% |
| Rottweil R 907 | <<locked>> | 82% | 54,592 psi | 86% | 2346 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 84% | 56,753 psi | 89% | 2362 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 54,911 psi | 86% | 2362 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 55,695 psi | 87% | 2326 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 55,550 psi | 87% | 2431 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 55,695 psi | 87% | 2375 fps | 99.5% |
| Somchem S365 | <<locked>> | 86% | 55,085 psi | 86% | 2375 fps | 100% |
| Somchem S385 | <<locked>> | 90% | 56,449 psi | 88% | 2408 fps | 100% |
| Vihtavuori N150 | <<locked>> | 82% | 56,753 psi | 89% | 2306 fps | 100% |
| Vihtavuori N160 | <<locked>> | 84% | 56,217 psi | 88% | 2369 fps | 100% |
| Vihtavuori N165 | <<locked>> | 94% | 55,985 psi | 88% | 2392 fps | 100% |
| Vihtavuori N170 | <<locked>> | 98% | 54,404 psi | 85% | 2408 fps | 96.5% |
| Vihtavuori N550 | <<locked>> | 84% | 55,303 psi | 87% | 2375 fps | 100% |
| Vihtavuori N555 | <<locked>> | 90% | 54,897 psi | 86% | 2402 fps | 100% |
| Vihtavuori N560 | <<locked>> | 90% | 54,433 psi | 85% | 2477 fps | 99.6% |
| Vihtavuori N565 | <<locked>> | 96% | 54,462 psi | 85% | 2464 fps | 99.7% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 54,955 psi | 86% | 2516 fps | 99.3% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 52,040 psi | 82% | 2516 fps | 97.5% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 55,463 psi | 87% | 2329 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 54,230 psi | 85% | 2398 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 94% | 54,346 psi | 85% | 2497 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 92% | 56,260 psi | 88% | 2408 fps | 100% |
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% | 36,941 psi | 58% | 2116 fps | 99.6% |
| Accurate 4350 | <<locked>> | 80% | 49,211 psi | 77% | 2306 fps | 100% |
| Accurate High Country | <<locked>> | 80% | 39,914 psi | 63% | 2257 fps | 97.9% |
| Accurate MAGPRO | <<locked>> | 80% | 37,608 psi | 59% | 2208 fps | 95.9% |
| ADI AR 2209 | <<locked>> | 80% | 40,843 psi | 64% | 2218 fps | 98.7% |
| ADI AR 2213 | <<locked>> | 80% | 36,477 psi | 57% | 2165 fps | 96.5% |
| ADI AR 2217 | <<locked>> | 86% | 33,112 psi | 52% | 2096 fps | 95.5% |
| ADI AR 2225 | <<locked>> | 82% | 26,353 psi | 41% | 1975 fps | 95.4% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 41,321 psi | 65% | 2221 fps | 98.8% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 41,321 psi | 65% | 2221 fps | 98.8% |
| Alliant Reloder-16 | <<locked>> | 80% | 46,949 psi | 74% | 2310 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 40,944 psi | 64% | 2215 fps | 98.8% |
| Alliant Reloder-22 | <<locked>> | 80% | 36,753 psi | 58% | 2175 fps | 98% |
| Alliant Reloder-23 | <<locked>> | 80% | 35,476 psi | 56% | 2133 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 30,763 psi | 48% | 2077 fps | 99.1% |
| Alliant Reloder-26 | <<locked>> | 80% | 39,015 psi | 61% | 2260 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 96% | 42,250 psi | 66% | 2346 fps | 95.3% |
| Baschieri & Pellagri 109 | <<locked>> | 86% | 43,743 psi | 69% | 2244 fps | 95.6% |
| Bofors RP15 | <<locked>> | 80% | 34,185 psi | 54% | 2123 fps | 97.1% |
| Bofors RP30 | <<locked>> | 84% | 32,271 psi | 51% | 2113 fps | 95.8% |
| Bofors RP5 | <<locked>> | 80% | 36,753 psi | 58% | 2175 fps | 98% |
| Bofors RP7 | <<locked>> | 80% | 51,184 psi | 80% | 2303 fps | 100% |
| Hodgdon H1000 | <<locked>> | 82% | 31,502 psi | 49% | 2060 fps | 95.5% |
| Hodgdon H414 | <<locked>> | 80% | 50,589 psi | 79% | 2349 fps | 100% |
| Hodgdon H4350 | <<locked>> | 80% | 53,026 psi | 83% | 2359 fps | 100% |
| Hodgdon H4831 | <<locked>> | 80% | 38,870 psi | 61% | 2169 fps | 96.6% |
| Hodgdon H4831 SC | <<locked>> | 80% | 38,247 psi | 60% | 2156 fps | 96.5% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 44,338 psi | 69% | 2208 fps | 100% |
| Hodgdon Retumbo | 66.7 gr | 80% | 30,008 psi | 47% | 2096 fps | 96.2% |
| Hodgdon Superformance | <<locked>> | 80% | 50,459 psi | 79% | 2379 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,079 psi | 44% | 1322 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 46,615 psi | 73% | 2254 fps | 99.9% |
| IMR 4451 Enduron | <<locked>> | 80% | 52,591 psi | 82% | 2323 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 46,528 psi | 73% | 2260 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 40,509 psi | 63% | 2165 fps | 97.2% |
| IMR 7828 SSC | <<locked>> | 80% | 35,099 psi | 55% | 2149 fps | 96.2% |
| IMR 8133 Enduron | <<locked>> | 92% | 32,808 psi | 51% | 2146 fps | 95.8% |
| Lovex S065 | <<locked>> | 80% | 50,125 psi | 79% | 2280 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 48,443 psi | 76% | 2277 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 31,908 psi | 50% | 2018 fps | 98.6% |
| Norma 204 | <<locked>> | 80% | 46,775 psi | 73% | 2293 fps | 99.5% |
| Norma 217 | <<locked>> | 86% | 27,021 psi | 42% | 2021 fps | 95.4% |
| Norma MRP | <<locked>> | 80% | 38,464 psi | 60% | 2231 fps | 99.4% |
| Norma URP | <<locked>> | 80% | 47,863 psi | 75% | 2290 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 34,722 psi | 54% | 2156 fps | 96.5% |
| Ramshot Hunter | <<locked>> | 80% | 46,688 psi | 73% | 2297 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 30,850 psi | 48% | 2057 fps | 96.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,703 psi | 45% | 1352 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 48,979 psi | 77% | 2326 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 47,224 psi | 74% | 2346 fps | 100% |
| ReloadSwiss RS 76 | 71.4 gr | 80% | 28,950 psi | 45% | 2073 fps | 96.9% |
| ReloadSwiss RS 80 | <<locked>> | 90% | 37,188 psi | 58% | 2247 fps | 96% |
| Rottweil R 904 | <<locked>> | 80% | 42,090 psi | 66% | 2198 fps | 98.1% |
| Rottweil R 905 | <<locked>> | 80% | 40,379 psi | 63% | 2205 fps | 98.8% |
| Rottweil R 907 | <<locked>> | 80% | 51,184 psi | 80% | 2303 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 80% | 50,125 psi | 79% | 2280 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 48,443 psi | 76% | 2277 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 49,066 psi | 77% | 2241 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 40,045 psi | 63% | 2201 fps | 98.7% |
| Somchem S361 | <<locked>> | 80% | 42,786 psi | 67% | 2192 fps | 97.6% |
| Somchem S365 | <<locked>> | 80% | 45,194 psi | 71% | 2254 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 40,828 psi | 64% | 2188 fps | 99.3% |
| Vihtavuori N150 | <<locked>> | 80% | 53,171 psi | 83% | 2267 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 49,443 psi | 77% | 2283 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 35,491 psi | 56% | 2087 fps | 98% |
| Vihtavuori N170 | <<locked>> | 96% | 50,966 psi | 80% | 2359 fps | 95.7% |
| Vihtavuori N550 | <<locked>> | 80% | 48,646 psi | 76% | 2290 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 39,813 psi | 62% | 2195 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 38,537 psi | 60% | 2221 fps | 96.8% |
| Vihtavuori N565 | <<locked>> | 82% | 34,011 psi | 53% | 2126 fps | 95.6% |
| Vihtavuori N568 | <<locked>> | 90% | 38,682 psi | 61% | 2260 fps | 95.8% |
| Vihtavuori N570 | <<locked>> | 96% | 45,150 psi | 71% | 2405 fps | 95.8% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 48,356 psi | 76% | 2247 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 50,778 psi | 80% | 2352 fps | 100% |
| Winchester StaBALL HD | 68.5 gr | 80% | 31,792 psi | 50% | 2172 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 37,347 psi | 59% | 2129 fps | 98% |
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 76 powders for .338 Rem. Ultra Mag. loaded with the .338 | 300gr | Hornady HPBT. Hodgdon Retumbo delivers the highest muzzle velocity at 2,552 fps; across all powders the maximum-charge window runs from 1,480 fps to 2,552 fps. ADI AR 2217 gives the best case fill at 100 %, and 76 of the 76 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 300.0 gr projectile in 0.338" calls for a 1:12.0 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2225, Alliant Reloder-33 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, Winchester StaBALL HD rank at the top here: for .338 Rem. Ultra Mag. with the .338 | 300gr | Hornady HPBT 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.