Load Specifications
Bullet:.338 | 250gr | Norma GTX
Bullet Manufacturer:Norma
Bullet Weight:250 gr
Bullet Diameter:0.338"
Bullet Length:<<locked>>
Caliber:.338 Weatherby RPM load data
Case Length (l3):2.55"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:81.6 Grains of Water
Primer Size:Large Rifle Magnum (LRM)
Barrel Length:24"
Max. allowed Pressure:65,000 psi
Recommended Twist Rate:1:12.5
Load data in caliber .338 Weatherby RPM with .338 | 250gr | Norma GTX bullet and 108 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ReloadSwiss RS 60, Alliant Power Pro 2000-MR and Alliant Reloder-17.
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 2015 | <<locked>> | 86% | 56,550 psi | 87% | 2379 fps | 100% |
| Accurate 2460 | <<locked>> | 84% | 58,755 psi | 90% | 2451 fps | 100% |
| Accurate 2495 | <<locked>> | 92% | 58,595 psi | 90% | 2444 fps | 100% |
| Accurate 2520 | <<locked>> | 86% | 57,043 psi | 88% | 2467 fps | 100% |
| Accurate 2700 | <<locked>> | 92% | 58,131 psi | 89% | 2457 fps | 98% |
| Accurate 3100ᴾ | <<locked>> | 100% | 38,392 psi | 59% | 2274 fps | 95.8% |
| Accurate 4064 | <<locked>> | 94% | 58,421 psi | 90% | 2490 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 54,157 psi | 83% | 2526 fps | 99.8% |
| Accurate LT-30 | <<locked>> | 82% | 58,784 psi | 90% | 2365 fps | 100% |
| ADI AR 2206H | <<locked>> | 88% | 55,680 psi | 86% | 2477 fps | 100% |
| ADI AR 2208 | <<locked>> | 94% | 56,420 psi | 87% | 2474 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 88% | 58,218 psi | 90% | 2477 fps | 100% |
| Alliant AR-Comp | <<locked>> | 86% | 55,419 psi | 85% | 2405 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 82% | 56,768 psi | 87% | 2526 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 90% | 55,042 psi | 85% | 2585 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 94% | 56,420 psi | 87% | 2497 fps | 100% |
| Alliant Reloder-10x | <<locked>> | 82% | 56,304 psi | 87% | 2382 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 92% | 57,043 psi | 88% | 2516 fps | 100% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 52,228 psi | 80% | 2526 fps | 99.9% |
| Alliant Reloder-17 | <<locked>> | 98% | 56,768 psi | 87% | 2608 fps | 100% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 37,260 psi | 57% | 2303 fps | 98.9% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 41,191 psi | 63% | 2438 fps | 98% |
| Baschieri & Pellagri 106 | <<locked>> | 82% | 57,928 psi | 89% | 2365 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 88% | 55,288 psi | 85% | 2497 fps | 99.9% |
| Bofors RP3 | <<locked>> | 94% | 56,956 psi | 88% | 2510 fps | 100% |
| Bofors RP7 | <<locked>> | 98% | 57,145 psi | 88% | 2487 fps | 98.1% |
| Hodgdon Benchmark | <<locked>> | 86% | 56,594 psi | 87% | 2418 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 88% | 57,421 psi | 88% | 2507 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 84% | 55,738 psi | 86% | 2549 fps | 100% |
| Hodgdon H322 | <<locked>> | 82% | 55,332 psi | 85% | 2421 fps | 100% |
| Hodgdon H335 | <<locked>> | 82% | 56,217 psi | 86% | 2448 fps | 100% |
| Hodgdon H380 | <<locked>> | 94% | 58,088 psi | 89% | 2526 fps | 99.8% |
| Hodgdon H414ᴾ | <<locked>> | 100% | 57,058 psi | 88% | 2569 fps | 98.7% |
| Hodgdon H4350 | <<locked>> | 98% | 58,102 psi | 89% | 2536 fps | 97.7% |
| Hodgdon H4895 | <<locked>> | 88% | 56,202 psi | 86% | 2487 fps | 100% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 48,341 psi | 74% | 2418 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 90% | 55,303 psi | 85% | 2516 fps | 100% |
| Hodgdon Superformanceᴾ | <<locked>> | 100% | 58,378 psi | 90% | 2612 fps | 98.5% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,389 psi | 54% | 1463 fps | 100% |
| Hodgdon VARGET | <<locked>> | 90% | 57,421 psi | 88% | 2487 fps | 100% |
| IMR 3031 | <<locked>> | 88% | 56,014 psi | 86% | 2464 fps | 100% |
| IMR 4064 | <<locked>> | 92% | 56,188 psi | 86% | 2464 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 90% | 56,217 psi | 86% | 2448 fps | 98.4% |
| IMR 4198 | <<locked>> | 82% | 56,347 psi | 87% | 2339 fps | 100% |
| IMR 4350ᴾ | <<locked>> | 100% | 53,505 psi | 82% | 2461 fps | 97.6% |
| IMR 4451 Enduron | <<locked>> | 96% | 55,666 psi | 86% | 2467 fps | 98.3% |
| IMR 4831ᴾ | <<locked>> | 100% | 51,213 psi | 79% | 2470 fps | 99.6% |
| IMR 4895 | <<locked>> | 92% | 58,566 psi | 90% | 2543 fps | 100% |
| IMR 8208 XBR | <<locked>> | 88% | 58,218 psi | 90% | 2477 fps | 100% |
| Lovex D073.5 | <<locked>> | 84% | 58,494 psi | 90% | 2464 fps | 100% |
| Lovex D073.6 | <<locked>> | 88% | 55,230 psi | 85% | 2454 fps | 100% |
| Lovex S060 | <<locked>> | 90% | 58,682 psi | 90% | 2454 fps | 100% |
| Lovex S062 | <<locked>> | 92% | 55,854 psi | 86% | 2457 fps | 100% |
| Lovex S065ᴾ | <<locked>> | 100% | 58,218 psi | 90% | 2507 fps | 99.5% |
| Lovex S070ᴾ | <<locked>> | 100% | 55,434 psi | 85% | 2490 fps | 98.5% |
| Norma 201 | <<locked>> | 90% | 57,812 psi | 89% | 2470 fps | 100% |
| Norma 202 | <<locked>> | 90% | 58,320 psi | 90% | 2467 fps | 100% |
| Norma 203B | <<locked>> | 92% | 56,202 psi | 86% | 2503 fps | 100% |
| Norma 204ᴾ | <<locked>> | 100% | 54,114 psi | 83% | 2507 fps | 96.4% |
| Norma URPᴾ | <<locked>> | 100% | 53,142 psi | 82% | 2513 fps | 99.7% |
| Ramshot Big Game | <<locked>> | 92% | 56,753 psi | 87% | 2530 fps | 100% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 51,967 psi | 80% | 2510 fps | 98.7% |
| Ramshot TAC | <<locked>> | 88% | 58,552 psi | 90% | 2503 fps | 99.6% |
| Ramshot Wild Boar | <<locked>> | 88% | 58,088 psi | 89% | 2516 fps | 100% |
| Ramshot X-Terminator | <<locked>> | 84% | 55,695 psi | 86% | 2438 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 35,882 psi | 55% | 1499 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 84% | 57,885 psi | 89% | 2457 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 94% | 58,276 psi | 90% | 2507 fps | 99.1% |
| ReloadSwiss RS 52 | <<locked>> | 90% | 57,450 psi | 88% | 2575 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 96% | 56,782 psi | 87% | 2605 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 53,403 psi | 82% | 2543 fps | 99.7% |
| ReloadSwiss RS 70ᴾ | <<locked>> | 100% | 53,664 psi | 83% | 2572 fps | 99.6% |
| Rottweil R 901 | <<locked>> | 88% | 58,697 psi | 90% | 2444 fps | 100% |
| Rottweil R 902 | <<locked>> | 92% | 58,204 psi | 90% | 2467 fps | 100% |
| Rottweil R 903 | <<locked>> | 96% | 56,550 psi | 87% | 2500 fps | 100% |
| Rottweil R 907 | <<locked>> | 98% | 57,145 psi | 88% | 2487 fps | 98.1% |
| Shooters World Long Rifleᴾ | <<locked>> | 100% | 58,218 psi | 90% | 2507 fps | 99.5% |
| Shooters World Match Rifle | <<locked>> | 88% | 55,230 psi | 85% | 2454 fps | 100% |
| Shooters World Precision | <<locked>> | 92% | 55,854 psi | 86% | 2457 fps | 100% |
| Shooters World SW4350ᴾ | <<locked>> | 100% | 55,434 psi | 85% | 2490 fps | 98.5% |
| Shooters World Tactical Rifle | <<locked>> | 82% | 57,508 psi | 88% | 2434 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 96% | 58,624 psi | 90% | 2559 fps | 100% |
| SNPE Vectan SP 3 | <<locked>> | 82% | 57,261 psi | 88% | 2398 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 88% | 56,927 psi | 88% | 2480 fps | 99.7% |
| SNPE Vectan SP 9 | <<locked>> | 90% | 57,319 psi | 88% | 2497 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 88% | 56,101 psi | 86% | 2372 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 94% | 55,970 psi | 86% | 2369 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 98% | 55,201 psi | 85% | 2421 fps | 98.2% |
| Somchem S321 | <<locked>> | 84% | 55,854 psi | 86% | 2464 fps | 100% |
| Somchem S335 | <<locked>> | 90% | 58,639 psi | 90% | 2408 fps | 100% |
| Somchem S341 | <<locked>> | 88% | 56,449 psi | 87% | 2474 fps | 100% |
| Somchem S355 | <<locked>> | 96% | 56,927 psi | 88% | 2497 fps | 100% |
| Somchem S365ᴾ | <<locked>> | 100% | 47,500 psi | 73% | 2470 fps | 100% |
| Vihtavuori N130 | <<locked>> | 84% | 55,840 psi | 86% | 2333 fps | 100% |
| Vihtavuori N133 | <<locked>> | 88% | 56,246 psi | 87% | 2356 fps | 100% |
| Vihtavuori N135 | <<locked>> | 92% | 57,899 psi | 89% | 2431 fps | 100% |
| Vihtavuori N140 | <<locked>> | 90% | 55,317 psi | 85% | 2408 fps | 100% |
| Vihtavuori N150 | <<locked>> | 98% | 58,523 psi | 90% | 2477 fps | 100% |
| Vihtavuori N160ᴾ | <<locked>> | 100% | 55,956 psi | 86% | 2510 fps | 99.8% |
| Vihtavuori N530 | <<locked>> | 86% | 55,100 psi | 85% | 2431 fps | 100% |
| Vihtavuori N540 | <<locked>> | 92% | 56,927 psi | 88% | 2451 fps | 100% |
| Vihtavuori N550ᴾ | <<locked>> | 100% | 54,882 psi | 84% | 2516 fps | 99.7% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 40,263 psi | 62% | 2369 fps | 98.7% |
| Winchester 6.5 StaBALLᴾ | <<locked>> | 100% | 56,304 psi | 87% | 2490 fps | 100% |
| Winchester 748 | <<locked>> | 88% | 58,523 psi | 90% | 2520 fps | 100% |
| Winchester 760ᴾ | <<locked>> | 100% | 57,334 psi | 88% | 2572 fps | 98.7% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 33,127 psi | 51% | 2300 fps | 98.6% |
| Winchester StaBALL Match | <<locked>> | 90% | 57,305 psi | 88% | 2507 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 2015 | <<locked>> | 80% | 47,181 psi | 73% | 2264 fps | 100% |
| Accurate 2460 | <<locked>> | 80% | 51,532 psi | 79% | 2365 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 39,740 psi | 61% | 2205 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 46,572 psi | 72% | 2336 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 44,875 psi | 69% | 2270 fps | 95.4% |
| Accurate 3100 | <<locked>> | 98% | 35,911 psi | 55% | 2228 fps | 95% |
| Accurate 4064 | <<locked>> | 80% | 37,550 psi | 58% | 2201 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 31,343 psi | 48% | 2142 fps | 95.4% |
| Accurate LT-30 | <<locked>> | 80% | 55,259 psi | 85% | 2326 fps | 100% |
| ADI AR 2206H | <<locked>> | 80% | 43,439 psi | 67% | 2300 fps | 99.4% |
| ADI AR 2208 | <<locked>> | 80% | 36,985 psi | 57% | 2172 fps | 97.7% |
| ADI Benchmark 8208 | <<locked>> | 80% | 45,469 psi | 70% | 2306 fps | 100% |
| Alliant AR-Comp | <<locked>> | 80% | 45,542 psi | 70% | 2287 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 80% | 53,185 psi | 82% | 2480 fps | 100% |
| Alliant Power Pro 2000-MR | 51.1 gr | 80% | 39,218 psi | 60% | 2326 fps | 98.2% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 36,434 psi | 56% | 2192 fps | 98.9% |
| Alliant Reloder-10x | <<locked>> | 80% | 53,098 psi | 82% | 2343 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 39,160 psi | 60% | 2244 fps | 98.4% |
| Alliant Reloder-16 | <<locked>> | 84% | 32,184 psi | 50% | 2156 fps | 95.6% |
| Alliant Reloder-17 | 50.3 gr | 80% | 31,328 psi | 48% | 2165 fps | 97.2% |
| Alliant Reloder-23 | <<locked>> | 90% | 27,572 psi | 42% | 2073 fps | 95.1% |
| Alliant Reloder-26 | <<locked>> | 94% | 33,533 psi | 52% | 2274 fps | 95.2% |
| Baschieri & Pellagri 106 | <<locked>> | 80% | 54,389 psi | 84% | 2326 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 42,337 psi | 65% | 2303 fps | 98.6% |
| Bofors RP3 | <<locked>> | 80% | 35,940 psi | 55% | 2195 fps | 98.9% |
| Bofors RP7 | <<locked>> | 88% | 42,032 psi | 65% | 2260 fps | 95% |
| Hodgdon Benchmark | <<locked>> | 80% | 47,137 psi | 73% | 2290 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 43,976 psi | 68% | 2326 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 80% | 48,472 psi | 75% | 2451 fps | 99.7% |
| Hodgdon H322 | <<locked>> | 80% | 51,851 psi | 80% | 2379 fps | 100% |
| Hodgdon H335 | <<locked>> | 80% | 52,823 psi | 81% | 2405 fps | 100% |
| Hodgdon H380 | <<locked>> | 80% | 36,796 psi | 57% | 2195 fps | 96.6% |
| Hodgdon H414 | <<locked>> | 90% | 41,278 psi | 64% | 2329 fps | 95.6% |
| Hodgdon H4350 | <<locked>> | 90% | 45,295 psi | 70% | 2349 fps | 95.1% |
| Hodgdon H4895 | <<locked>> | 80% | 43,801 psi | 67% | 2310 fps | 99.7% |
| Hodgdon Hybrid 100V | <<locked>> | 82% | 27,659 psi | 43% | 2024 fps | 95.6% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 39,595 psi | 61% | 2287 fps | 99.5% |
| Hodgdon Superformance | <<locked>> | 92% | 44,019 psi | 68% | 2398 fps | 95.6% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,455 psi | 41% | 1306 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 41,959 psi | 65% | 2267 fps | 99.5% |
| IMR 3031 | <<locked>> | 80% | 43,410 psi | 67% | 2300 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 38,841 psi | 60% | 2201 fps | 98.4% |
| IMR 4166 Enduron | <<locked>> | 80% | 41,162 psi | 63% | 2215 fps | 95.3% |
| IMR 4198 | <<locked>> | 80% | 53,127 psi | 82% | 2303 fps | 100% |
| IMR 4350 | <<locked>> | 92% | 41,989 psi | 65% | 2283 fps | 95% |
| IMR 4451 Enduron | <<locked>> | 86% | 41,234 psi | 63% | 2247 fps | 95.3% |
| IMR 4831 | <<locked>> | 84% | 30,487 psi | 47% | 2106 fps | 95.1% |
| IMR 4895 | <<locked>> | 80% | 40,118 psi | 62% | 2274 fps | 99% |
| IMR 8208 XBR | <<locked>> | 80% | 45,469 psi | 70% | 2306 fps | 100% |
| Lovex D073.5 | <<locked>> | 80% | 51,343 psi | 79% | 2375 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 42,235 psi | 65% | 2280 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 43,642 psi | 67% | 2244 fps | 99.4% |
| Lovex S062 | <<locked>> | 80% | 38,711 psi | 60% | 2205 fps | 99.5% |
| Lovex S065 | <<locked>> | 84% | 35,911 psi | 55% | 2156 fps | 95.3% |
| Lovex S070 | <<locked>> | 90% | 40,828 psi | 63% | 2267 fps | 95.6% |
| Norma 201 | <<locked>> | 80% | 42,453 psi | 65% | 2257 fps | 99.8% |
| Norma 202 | <<locked>> | 80% | 42,801 psi | 66% | 2264 fps | 100% |
| Norma 203B | <<locked>> | 80% | 38,580 psi | 59% | 2238 fps | 98.7% |
| Norma 204 | <<locked>> | 98% | 50,691 psi | 78% | 2457 fps | 95.7% |
| Norma URP | <<locked>> | 84% | 31,894 psi | 49% | 2146 fps | 95.4% |
| Ramshot Big Game | <<locked>> | 80% | 37,884 psi | 58% | 2247 fps | 98.4% |
| Ramshot Hunter | <<locked>> | 90% | 37,782 psi | 58% | 2270 fps | 95.4% |
| Ramshot TAC | <<locked>> | 80% | 45,150 psi | 69% | 2313 fps | 97.9% |
| Ramshot Wild Boar | <<locked>> | 80% | 44,744 psi | 69% | 2329 fps | 99.5% |
| Ramshot X-Terminator | <<locked>> | 80% | 48,892 psi | 75% | 2346 fps | 99.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,760 psi | 41% | 1339 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 50,850 psi | 78% | 2369 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 39,900 psi | 61% | 2231 fps | 95.7% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 40,828 psi | 63% | 2333 fps | 98.7% |
| ReloadSwiss RS 60 | 50.3 gr | 80% | 33,359 psi | 51% | 2221 fps | 99.6% |
| ReloadSwiss RS 62 | <<locked>> | 86% | 33,243 psi | 51% | 2201 fps | 95.6% |
| ReloadSwiss RS 70 | <<locked>> | 88% | 35,926 psi | 55% | 2257 fps | 95.6% |
| Rottweil R 901 | <<locked>> | 80% | 46,557 psi | 72% | 2290 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 40,611 psi | 62% | 2218 fps | 99.7% |
| Rottweil R 903 | <<locked>> | 80% | 33,924 psi | 52% | 2149 fps | 98.3% |
| Rottweil R 907 | <<locked>> | 88% | 42,032 psi | 65% | 2260 fps | 95% |
| Shooters World Long Rifle | <<locked>> | 84% | 35,911 psi | 55% | 2156 fps | 95.3% |
| Shooters World Match Rifle | <<locked>> | 80% | 42,235 psi | 65% | 2280 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 38,711 psi | 60% | 2205 fps | 99.5% |
| Shooters World SW4350 | <<locked>> | 90% | 40,828 psi | 63% | 2267 fps | 95.6% |
| Shooters World Tactical Rifle | <<locked>> | 80% | 53,679 psi | 83% | 2388 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 34,679 psi | 53% | 2188 fps | 97.7% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 53,954 psi | 83% | 2362 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 43,540 psi | 67% | 2290 fps | 98.1% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 41,742 psi | 64% | 2274 fps | 99.2% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 44,034 psi | 68% | 2215 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 36,550 psi | 56% | 2103 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 39,900 psi | 61% | 2195 fps | 95.1% |
| Somchem S321 | <<locked>> | 80% | 48,892 psi | 75% | 2372 fps | 100% |
| Somchem S335 | <<locked>> | 80% | 43,453 psi | 67% | 2215 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 43,091 psi | 66% | 2287 fps | 99.3% |
| Somchem S355 | <<locked>> | 80% | 34,708 psi | 53% | 2152 fps | 98.2% |
| Somchem S365 | <<locked>> | 80% | 25,164 psi | 39% | 2008 fps | 95.9% |
| Vihtavuori N130 | <<locked>> | 80% | 49,748 psi | 77% | 2260 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 44,338 psi | 68% | 2208 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 39,987 psi | 62% | 2201 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 40,596 psi | 62% | 2208 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 33,112 psi | 51% | 2100 fps | 98.9% |
| Vihtavuori N160 | <<locked>> | 82% | 31,372 psi | 48% | 2103 fps | 95% |
| Vihtavuori N530 | <<locked>> | 80% | 45,484 psi | 70% | 2300 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 38,885 psi | 60% | 2201 fps | 100% |
| Vihtavuori N550 | <<locked>> | 84% | 32,793 psi | 50% | 2149 fps | 95.4% |
| Vihtavuori N555 | <<locked>> | 90% | 29,254 psi | 45% | 2136 fps | 95.2% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 29,269 psi | 45% | 2034 fps | 96.4% |
| Winchester 748 | <<locked>> | 80% | 44,904 psi | 69% | 2339 fps | 100% |
| Winchester 760 | <<locked>> | 90% | 41,278 psi | 64% | 2329 fps | 95.6% |
| Winchester StaBALL HD | <<locked>> | 94% | 27,499 psi | 42% | 2133 fps | 95.3% |
| Winchester StaBALL Match | <<locked>> | 80% | 41,234 psi | 63% | 2277 fps | 99.5% |
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 108 powders for .338 Weatherby RPM loaded with the .338 | 250gr | Norma GTX. Hodgdon Superformance delivers the highest muzzle velocity at 2,612 fps; across all powders the maximum-charge window runs from 1,463 fps to 2,612 fps. Accurate 3100 gives the best case fill at 100 %, and 108 of the 108 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (448 MPa), the top charges use 51–90 %, leaving at least 10 % headroom. The 250.0 gr projectile in 0.338" calls for a 1:12.5 twist; slower twists will usually not stabilise this weight. Accurate 3100, Accurate 4350, Alliant Reloder-16 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. ReloadSwiss RS 60, Alliant Power Pro 2000-MR, Alliant Reloder-17 rank at the top here: for .338 Weatherby RPM with the .338 | 250gr | Norma GTX 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.