Load Specifications
Load data in caliber .338 Rem. Ultra Mag. with .338 | 307gr | Hornady Sub-X bullet and 74 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>> | 90% | 54,752 psi | 86% | 2359 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 55,666 psi | 87% | 2369 fps | 100% |
| Accurate MAGPRO | <<locked>> | 90% | 57,203 psi | 90% | 2503 fps | 99.8% |
| ADI AR 2209 | <<locked>> | 88% | 56,260 psi | 88% | 2431 fps | 100% |
| ADI AR 2213 | <<locked>> | 90% | 54,230 psi | 85% | 2444 fps | 99.9% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 56,115 psi | 88% | 2470 fps | 100% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 48,501 psi | 76% | 2457 fps | 97.5% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 50,502 psi | 79% | 2444 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 88% | 56,420 psi | 88% | 2428 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 84% | 56,681 psi | 89% | 2411 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 55,782 psi | 87% | 2421 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 90% | 54,607 psi | 86% | 2441 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 92% | 56,260 psi | 88% | 2402 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 96% | 55,840 psi | 88% | 2464 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 88% | 56,637 psi | 89% | 2484 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 52,837 psi | 83% | 2503 fps | 98.5% |
| Alliant Reloder-50ᴾ | <<locked>> | 100% | 44,483 psi | 70% | 2379 fps | 96.2% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 55,216 psi | 87% | 2415 fps | 98.7% |
| Bofors RP15 | <<locked>> | 94% | 57,377 psi | 90% | 2474 fps | 100% |
| Bofors RP30 | <<locked>> | 98% | 55,593 psi | 87% | 2480 fps | 100% |
| Bofors RP5 | <<locked>> | 90% | 54,607 psi | 86% | 2441 fps | 100% |
| Bofors RP7 | <<locked>> | 82% | 57,188 psi | 90% | 2369 fps | 100% |
| Hodgdon H1000 | <<locked>> | 98% | 57,740 psi | 90% | 2487 fps | 100% |
| Hodgdon H414 | <<locked>> | 82% | 56,956 psi | 89% | 2418 fps | 100% |
| Hodgdon H4831 | <<locked>> | 90% | 57,580 psi | 90% | 2438 fps | 99.9% |
| Hodgdon H4831 SC | <<locked>> | 90% | 56,478 psi | 89% | 2421 fps | 99.8% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 56,840 psi | 89% | 2346 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 96% | 54,737 psi | 86% | 2539 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 57,682 psi | 90% | 2454 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,463 psi | 59% | 1476 fps | 100% |
| IMR 4350 | <<locked>> | 84% | 55,506 psi | 87% | 2362 fps | 100% |
| IMR 4831 | <<locked>> | 84% | 55,840 psi | 88% | 2362 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 88% | 54,650 psi | 86% | 2372 fps | 99.7% |
| IMR 7828 SSC | <<locked>> | 92% | 56,188 psi | 88% | 2477 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 96% | 56,463 psi | 88% | 2365 fps | 95.7% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 46,006 psi | 72% | 2375 fps | 99.6% |
| Lovex S065 | <<locked>> | 82% | 55,811 psi | 87% | 2339 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 57,696 psi | 90% | 2385 fps | 100% |
| Lovex S071 | <<locked>> | 96% | 55,999 psi | 88% | 2372 fps | 100% |
| Norma 204 | <<locked>> | 84% | 56,608 psi | 89% | 2415 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 46,615 psi | 73% | 2395 fps | 100% |
| Norma MRP | <<locked>> | 88% | 54,447 psi | 85% | 2454 fps | 100% |
| Norma URP | <<locked>> | 84% | 57,479 psi | 90% | 2398 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 57,392 psi | 90% | 2497 fps | 100% |
| Ramshot Hunter | <<locked>> | 84% | 56,420 psi | 88% | 2411 fps | 100% |
| Ramshot Magnum | <<locked>> | 94% | 55,419 psi | 87% | 2438 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,450 psi | 60% | 1516 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 55,753 psi | 87% | 2392 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 82% | 54,041 psi | 85% | 2418 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 55,114 psi | 86% | 2533 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 54,317 psi | 85% | 2507 fps | 99.7% |
| Rottweil R 904 | <<locked>> | 88% | 57,217 psi | 90% | 2405 fps | 100% |
| Rottweil R 905 | <<locked>> | 88% | 55,637 psi | 87% | 2415 fps | 100% |
| Rottweil R 907 | <<locked>> | 82% | 57,188 psi | 90% | 2369 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 82% | 55,811 psi | 87% | 2339 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 57,696 psi | 90% | 2385 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 82% | 54,766 psi | 86% | 2303 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 55,230 psi | 87% | 2411 fps | 100% |
| Somchem S361 | <<locked>> | 86% | 54,969 psi | 86% | 2356 fps | 99.7% |
| Somchem S365 | <<locked>> | 84% | 54,926 psi | 86% | 2356 fps | 100% |
| Somchem S385 | <<locked>> | 88% | 55,985 psi | 88% | 2388 fps | 100% |
| Vihtavuori N160 | <<locked>> | 82% | 55,579 psi | 87% | 2346 fps | 100% |
| Vihtavuori N165 | <<locked>> | 92% | 55,608 psi | 87% | 2375 fps | 100% |
| Vihtavuori N170 | <<locked>> | 96% | 54,172 psi | 85% | 2395 fps | 97% |
| Vihtavuori N550 | <<locked>> | 82% | 54,665 psi | 86% | 2352 fps | 100% |
| Vihtavuori N555 | <<locked>> | 88% | 54,897 psi | 86% | 2385 fps | 100% |
| Vihtavuori N560 | <<locked>> | 88% | 54,128 psi | 85% | 2457 fps | 99.8% |
| Vihtavuori N565 | <<locked>> | 94% | 54,462 psi | 85% | 2451 fps | 99.9% |
| Vihtavuori N568 | <<locked>> | 98% | 55,288 psi | 87% | 2510 fps | 99.6% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 56,130 psi | 88% | 2559 fps | 98.7% |
| Winchester 6.5 StaBALL | <<locked>> | 82% | 54,795 psi | 86% | 2306 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 57,174 psi | 90% | 2421 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 92% | 55,071 psi | 86% | 2480 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 90% | 55,608 psi | 87% | 2388 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% | 39,363 psi | 62% | 2142 fps | 99.9% |
| Accurate 4350 | <<locked>> | 80% | 52,156 psi | 82% | 2326 fps | 100% |
| Accurate MAGPRO | <<locked>> | 80% | 40,350 psi | 63% | 2247 fps | 97.3% |
| ADI AR 2209 | <<locked>> | 80% | 43,294 psi | 68% | 2247 fps | 99.4% |
| ADI AR 2213 | <<locked>> | 80% | 38,682 psi | 61% | 2201 fps | 97.8% |
| ADI AR 2217 | <<locked>> | 82% | 30,835 psi | 48% | 2037 fps | 95.2% |
| ADI AR 2218 | <<locked>> | 96% | 42,047 psi | 66% | 2339 fps | 95.4% |
| ADI AR 2225 | <<locked>> | 80% | 26,281 psi | 41% | 1965 fps | 96.2% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 43,743 psi | 69% | 2251 fps | 99.5% |
| Alliant Reloder-16 | <<locked>> | 80% | 49,893 psi | 78% | 2329 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 43,337 psi | 68% | 2244 fps | 99.5% |
| Alliant Reloder-22 | <<locked>> | 80% | 39,189 psi | 61% | 2208 fps | 99% |
| Alliant Reloder-23 | <<locked>> | 80% | 38,058 psi | 60% | 2159 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 32,808 psi | 51% | 2110 fps | 99.8% |
| Alliant Reloder-26 | <<locked>> | 80% | 42,192 psi | 66% | 2293 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 92% | 39,465 psi | 62% | 2283 fps | 95% |
| Alliant Reloder-50 | <<locked>> | 98% | 41,379 psi | 65% | 2323 fps | 95.2% |
| Baschieri & Pellagri 109 | <<locked>> | 82% | 40,538 psi | 64% | 2178 fps | 95.3% |
| Bofors RP15 | <<locked>> | 80% | 36,521 psi | 57% | 2156 fps | 98.3% |
| Bofors RP30 | <<locked>> | 80% | 30,327 psi | 48% | 2054 fps | 95.5% |
| Bofors RP5 | <<locked>> | 80% | 39,189 psi | 61% | 2208 fps | 99% |
| Bofors RP7 | <<locked>> | 80% | 53,708 psi | 84% | 2326 fps | 100% |
| Hodgdon H1000 | <<locked>> | 80% | 31,241 psi | 49% | 2047 fps | 96.1% |
| Hodgdon H414 | <<locked>> | 80% | 53,505 psi | 84% | 2375 fps | 100% |
| Hodgdon H4831 | <<locked>> | 80% | 41,292 psi | 65% | 2201 fps | 97.8% |
| Hodgdon H4831 SC | <<locked>> | 80% | 40,480 psi | 63% | 2185 fps | 97.6% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 46,949 psi | 74% | 2228 fps | 100% |
| Hodgdon Retumbo | 69.3 gr | 80% | 31,981 psi | 50% | 2139 fps | 97.8% |
| Hodgdon Superformance | <<locked>> | 80% | 53,461 psi | 84% | 2405 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,123 psi | 44% | 1319 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 49,052 psi | 77% | 2277 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 49,197 psi | 77% | 2280 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 42,670 psi | 67% | 2195 fps | 98.2% |
| IMR 7828 SSC | <<locked>> | 80% | 37,463 psi | 59% | 2188 fps | 97.6% |
| IMR 7977 Enduron | <<locked>> | 94% | 52,997 psi | 83% | 2320 fps | 95% |
| IMR 8133 Enduron | <<locked>> | 88% | 30,937 psi | 48% | 2090 fps | 95.6% |
| Lovex S065 | <<locked>> | 80% | 52,663 psi | 83% | 2300 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 50,995 psi | 80% | 2300 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 33,924 psi | 53% | 2044 fps | 99.4% |
| Norma 204 | <<locked>> | 80% | 49,472 psi | 78% | 2320 fps | 99.9% |
| Norma 217 | <<locked>> | 82% | 25,483 psi | 40% | 1965 fps | 95.1% |
| Norma MRP | <<locked>> | 80% | 41,394 psi | 65% | 2267 fps | 99.9% |
| Norma URP | <<locked>> | 80% | 50,618 psi | 79% | 2313 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 37,159 psi | 58% | 2195 fps | 97.9% |
| Ramshot Hunter | <<locked>> | 80% | 49,458 psi | 78% | 2323 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 33,156 psi | 52% | 2093 fps | 98.3% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,906 psi | 45% | 1355 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 52,156 psi | 82% | 2349 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 50,415 psi | 79% | 2372 fps | 100% |
| ReloadSwiss RS 76 | 74.2 gr | 80% | 30,980 psi | 49% | 2119 fps | 98.5% |
| ReloadSwiss RS 80 | <<locked>> | 86% | 34,751 psi | 54% | 2185 fps | 95.7% |
| Rottweil R 904 | <<locked>> | 80% | 44,440 psi | 70% | 2224 fps | 98.9% |
| Rottweil R 905 | <<locked>> | 80% | 42,728 psi | 67% | 2231 fps | 99.5% |
| Rottweil R 907 | <<locked>> | 80% | 53,708 psi | 84% | 2326 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 80% | 52,663 psi | 83% | 2300 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 50,995 psi | 80% | 2300 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 51,416 psi | 81% | 2260 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 42,395 psi | 66% | 2228 fps | 99.4% |
| Somchem S361 | <<locked>> | 80% | 45,179 psi | 71% | 2218 fps | 98.5% |
| Somchem S365 | <<locked>> | 80% | 48,153 psi | 75% | 2277 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 43,221 psi | 68% | 2215 fps | 99.8% |
| Vihtavuori N160 | <<locked>> | 80% | 52,141 psi | 82% | 2303 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 37,710 psi | 59% | 2116 fps | 98.9% |
| Vihtavuori N170 | <<locked>> | 92% | 47,413 psi | 74% | 2300 fps | 95.5% |
| Vihtavuori N550 | <<locked>> | 80% | 51,387 psi | 81% | 2313 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 42,395 psi | 66% | 2218 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 41,307 psi | 65% | 2260 fps | 98.1% |
| Vihtavuori N565 | <<locked>> | 80% | 34,011 psi | 53% | 2113 fps | 96.1% |
| Vihtavuori N568 | <<locked>> | 86% | 36,318 psi | 57% | 2201 fps | 95.6% |
| Vihtavuori N570 | <<locked>> | 92% | 42,293 psi | 66% | 2346 fps | 95.6% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 51,126 psi | 80% | 2267 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 53,505 psi | 84% | 2375 fps | 100% |
| Winchester StaBALL HD | 71.2 gr | 80% | 34,954 psi | 55% | 2205 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 39,595 psi | 62% | 2156 fps | 98.9% |
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 74 powders for .338 Rem. Ultra Mag. loaded with the .338 | 307gr | Hornady Sub-X. Vihtavuori N570 delivers the highest muzzle velocity at 2,559 fps; across all powders the maximum-charge window runs from 1,476 fps to 2,559 fps. ADI AR 2217 gives the best case fill at 100 %, and 74 of the 74 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 307.0 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 2218, 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. Hodgdon Retumbo, ReloadSwiss RS 76, Winchester StaBALL HD rank at the top here: for .338 Rem. Ultra Mag. with the .338 | 307gr | Hornady Sub-X 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.