Load Specifications
Bullet:.338 | 250gr | Swift A-Frame
Bullet Manufacturer:Swift
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:1:15.5
Load data in caliber .338 Weatherby RPM with .338 | 250gr | Swift A-Frame bullet and 106 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-17, ReloadSwiss RS 60 and Alliant Power Pro 2000-MR.
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>> | 84% | 56,086 psi | 86% | 2392 fps | 100% |
| Accurate 2460 | <<locked>> | 82% | 58,102 psi | 89% | 2464 fps | 100% |
| Accurate 2495 | <<locked>> | 90% | 58,392 psi | 90% | 2461 fps | 100% |
| Accurate 2520 | <<locked>> | 84% | 56,391 psi | 87% | 2480 fps | 100% |
| Accurate 2700 | <<locked>> | 90% | 57,508 psi | 88% | 2480 fps | 98.3% |
| Accurate 3100ᴾ | <<locked>> | 100% | 41,510 psi | 64% | 2346 fps | 97.1% |
| Accurate 4064 | <<locked>> | 92% | 58,392 psi | 90% | 2507 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 58,131 psi | 89% | 2595 fps | 100% |
| ADI AR 2206H | <<locked>> | 88% | 58,653 psi | 90% | 2539 fps | 100% |
| ADI AR 2208 | <<locked>> | 92% | 55,999 psi | 86% | 2493 fps | 100% |
| ADI AR 2209ᴾ | <<locked>> | 100% | 49,501 psi | 76% | 2480 fps | 96% |
| ADI Benchmark 8208 | <<locked>> | 86% | 57,522 psi | 88% | 2490 fps | 100% |
| Alliant AR-Comp | <<locked>> | 86% | 58,697 psi | 90% | 2457 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 90% | 58,552 psi | 90% | 2657 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 92% | 56,188 psi | 86% | 2516 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 90% | 56,840 psi | 87% | 2536 fps | 100% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 55,622 psi | 86% | 2598 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 96% | 56,971 psi | 88% | 2631 fps | 100% |
| Alliant Reloder-19ᴾ | <<locked>> | 100% | 48,283 psi | 74% | 2470 fps | 96% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 39,697 psi | 61% | 2375 fps | 99.5% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 44,280 psi | 68% | 2520 fps | 99% |
| Baschieri & Pellagri 107 | <<locked>> | 88% | 58,407 psi | 90% | 2559 fps | 100% |
| Bofors RP3 | <<locked>> | 92% | 56,913 psi | 88% | 2530 fps | 100% |
| Bofors RP7 | <<locked>> | 96% | 56,884 psi | 88% | 2510 fps | 98.4% |
| Hodgdon Benchmark | <<locked>> | 84% | 55,709 psi | 86% | 2428 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 86% | 57,101 psi | 88% | 2523 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 82% | 55,434 psi | 85% | 2566 fps | 100% |
| Hodgdon H322 | <<locked>> | 82% | 58,320 psi | 90% | 2477 fps | 100% |
| Hodgdon H380 | <<locked>> | 92% | 57,711 psi | 89% | 2546 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 98% | 57,246 psi | 88% | 2598 fps | 99% |
| Hodgdon H4350 | <<locked>> | 96% | 57,798 psi | 89% | 2559 fps | 98.1% |
| Hodgdon H4895 | <<locked>> | 86% | 55,666 psi | 86% | 2503 fps | 100% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 51,692 psi | 80% | 2484 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 90% | 58,784 psi | 90% | 2582 fps | 100% |
| Hodgdon Superformance | <<locked>> | 98% | 57,899 psi | 89% | 2635 fps | 98.8% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,607 psi | 55% | 1490 fps | 100% |
| Hodgdon VARGET | <<locked>> | 88% | 56,855 psi | 87% | 2503 fps | 100% |
| IMR 3031 | <<locked>> | 86% | 55,898 psi | 86% | 2480 fps | 100% |
| IMR 4064 | <<locked>> | 90% | 55,680 psi | 86% | 2480 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 88% | 55,419 psi | 85% | 2464 fps | 98.6% |
| IMR 4350ᴾ | <<locked>> | 100% | 56,942 psi | 88% | 2533 fps | 98.5% |
| IMR 4451 Enduron | <<locked>> | 96% | 58,508 psi | 90% | 2533 fps | 98.9% |
| IMR 4831ᴾ | <<locked>> | 100% | 54,824 psi | 84% | 2543 fps | 99.9% |
| IMR 4895 | <<locked>> | 90% | 58,305 psi | 90% | 2562 fps | 100% |
| IMR 8208 XBR | <<locked>> | 86% | 57,522 psi | 88% | 2490 fps | 100% |
| Lovex D073.5 | <<locked>> | 82% | 58,044 psi | 89% | 2480 fps | 100% |
| Lovex D073.6 | <<locked>> | 88% | 58,639 psi | 90% | 2513 fps | 100% |
| Lovex S060 | <<locked>> | 88% | 58,073 psi | 89% | 2470 fps | 100% |
| Lovex S062 | <<locked>> | 92% | 58,755 psi | 90% | 2513 fps | 100% |
| Lovex S065 | <<locked>> | 98% | 57,972 psi | 89% | 2530 fps | 99.6% |
| Lovex S070ᴾ | <<locked>> | 100% | 58,813 psi | 90% | 2559 fps | 99.2% |
| Norma 201 | <<locked>> | 88% | 57,377 psi | 88% | 2487 fps | 100% |
| Norma 202 | <<locked>> | 88% | 57,928 psi | 89% | 2487 fps | 100% |
| Norma 203B | <<locked>> | 90% | 55,999 psi | 86% | 2523 fps | 100% |
| Norma 204ᴾ | <<locked>> | 100% | 57,725 psi | 89% | 2582 fps | 97.5% |
| Norma MRPᴾ | <<locked>> | 100% | 44,338 psi | 68% | 2480 fps | 96.7% |
| Norma URPᴾ | <<locked>> | 100% | 56,797 psi | 87% | 2582 fps | 100% |
| Ramshot Big Game | <<locked>> | 90% | 56,492 psi | 87% | 2549 fps | 100% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 55,622 psi | 86% | 2585 fps | 99.4% |
| Ramshot TAC | <<locked>> | 86% | 57,856 psi | 89% | 2520 fps | 99.7% |
| Ramshot Wild Boar | <<locked>> | 86% | 57,624 psi | 89% | 2533 fps | 100% |
| Ramshot X-Terminator | <<locked>> | 84% | 58,363 psi | 90% | 2493 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,303 psi | 56% | 1529 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 82% | 57,029 psi | 88% | 2470 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 92% | 58,015 psi | 89% | 2533 fps | 99.3% |
| ReloadSwiss RS 52 | <<locked>> | 88% | 57,363 psi | 88% | 2595 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 94% | 56,565 psi | 87% | 2625 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 57,856 psi | 89% | 2621 fps | 100% |
| ReloadSwiss RS 70ᴾ | <<locked>> | 100% | 57,305 psi | 88% | 2648 fps | 99.9% |
| Rottweil R 901 | <<locked>> | 86% | 58,363 psi | 90% | 2464 fps | 100% |
| Rottweil R 902 | <<locked>> | 90% | 57,769 psi | 89% | 2484 fps | 100% |
| Rottweil R 903 | <<locked>> | 94% | 56,782 psi | 87% | 2523 fps | 100% |
| Rottweil R 905ᴾ | <<locked>> | 100% | 46,920 psi | 72% | 2451 fps | 95.9% |
| Rottweil R 907 | <<locked>> | 96% | 56,884 psi | 88% | 2510 fps | 98.4% |
| Shooters World Long Rifle | <<locked>> | 98% | 57,972 psi | 89% | 2530 fps | 99.6% |
| Shooters World Match Rifle | <<locked>> | 88% | 58,639 psi | 90% | 2513 fps | 100% |
| Shooters World Precision | <<locked>> | 92% | 58,755 psi | 90% | 2513 fps | 100% |
| Shooters World SW4350ᴾ | <<locked>> | 100% | 58,813 psi | 90% | 2559 fps | 99.2% |
| SNPE Vectan SP 11 | <<locked>> | 94% | 58,508 psi | 90% | 2582 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 86% | 56,391 psi | 87% | 2500 fps | 99.8% |
| SNPE Vectan SP 9 | <<locked>> | 88% | 56,927 psi | 88% | 2516 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 88% | 58,755 psi | 90% | 2421 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 92% | 55,651 psi | 86% | 2388 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 98% | 58,508 psi | 90% | 2490 fps | 99% |
| SNPE Vectan Tubal 8000ᴾ | <<locked>> | 100% | 46,499 psi | 72% | 2448 fps | 95.7% |
| Somchem S321 | <<locked>> | 82% | 55,129 psi | 85% | 2477 fps | 100% |
| Somchem S335 | <<locked>> | 88% | 58,204 psi | 90% | 2425 fps | 100% |
| Somchem S341 | <<locked>> | 86% | 55,985 psi | 86% | 2490 fps | 100% |
| Somchem S355 | <<locked>> | 94% | 56,840 psi | 87% | 2520 fps | 100% |
| Somchem S365ᴾ | <<locked>> | 100% | 51,343 psi | 79% | 2539 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 47,659 psi | 73% | 2438 fps | 96.9% |
| Vihtavuori N130 | <<locked>> | 84% | 58,407 psi | 90% | 2385 fps | 100% |
| Vihtavuori N133 | <<locked>> | 86% | 55,579 psi | 86% | 2369 fps | 100% |
| Vihtavuori N135 | <<locked>> | 90% | 57,522 psi | 88% | 2444 fps | 100% |
| Vihtavuori N140 | <<locked>> | 90% | 58,320 psi | 90% | 2464 fps | 100% |
| Vihtavuori N150 | <<locked>> | 96% | 58,363 psi | 90% | 2497 fps | 100% |
| Vihtavuori N160 | <<locked>> | 98% | 56,072 psi | 86% | 2533 fps | 99.9% |
| Vihtavuori N530 | <<locked>> | 86% | 58,160 psi | 89% | 2490 fps | 100% |
| Vihtavuori N540 | <<locked>> | 90% | 56,463 psi | 87% | 2467 fps | 100% |
| Vihtavuori N550ᴾ | <<locked>> | 100% | 58,494 psi | 90% | 2585 fps | 100% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 43,714 psi | 67% | 2441 fps | 99.5% |
| Winchester 6.5 StaBALL | <<locked>> | 98% | 56,072 psi | 86% | 2513 fps | 100% |
| Winchester 748 | <<locked>> | 86% | 58,334 psi | 90% | 2536 fps | 100% |
| Winchester 760 | <<locked>> | 98% | 57,246 psi | 88% | 2598 fps | 99% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 35,534 psi | 55% | 2388 fps | 99.6% |
| Winchester StaBALL Match | <<locked>> | 88% | 56,826 psi | 87% | 2523 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% | 49,705 psi | 76% | 2316 fps | 100% |
| Accurate 2460 | <<locked>> | 80% | 54,244 psi | 83% | 2418 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 42,438 psi | 65% | 2260 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 49,516 psi | 76% | 2395 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 41,466 psi | 64% | 2238 fps | 95% |
| Accurate 3100 | <<locked>> | 96% | 36,332 psi | 56% | 2254 fps | 95.6% |
| Accurate 4064 | <<locked>> | 80% | 40,161 psi | 62% | 2260 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 29,399 psi | 45% | 2113 fps | 95% |
| ADI AR 2206H | <<locked>> | 80% | 45,745 psi | 70% | 2359 fps | 99.8% |
| ADI AR 2208 | <<locked>> | 80% | 38,943 psi | 60% | 2231 fps | 98.5% |
| ADI AR 2209 | <<locked>> | 98% | 46,398 psi | 71% | 2431 fps | 95.2% |
| ADI Benchmark 8208 | <<locked>> | 80% | 47,848 psi | 74% | 2362 fps | 100% |
| Alliant AR-Comp | <<locked>> | 80% | 48,312 psi | 74% | 2339 fps | 100% |
| Alliant Power Pro 2000-MR | 54.2 gr | 80% | 41,553 psi | 64% | 2395 fps | 99% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 38,711 psi | 60% | 2254 fps | 99.5% |
| Alliant Reloder-15 | <<locked>> | 80% | 41,466 psi | 64% | 2306 fps | 99.1% |
| Alliant Reloder-16 | <<locked>> | 80% | 30,110 psi | 46% | 2126 fps | 95.1% |
| Alliant Reloder-17 | 53.4 gr | 80% | 33,359 psi | 51% | 2234 fps | 98.3% |
| Alliant Reloder-19 | <<locked>> | 98% | 45,571 psi | 70% | 2425 fps | 95.2% |
| Alliant Reloder-23 | <<locked>> | 88% | 27,717 psi | 43% | 2096 fps | 95.8% |
| Alliant Reloder-26 | <<locked>> | 92% | 33,605 psi | 52% | 2297 fps | 95.9% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 44,991 psi | 69% | 2369 fps | 99.2% |
| Bofors RP3 | <<locked>> | 80% | 38,421 psi | 59% | 2257 fps | 99.5% |
| Bofors RP7 | <<locked>> | 86% | 41,727 psi | 64% | 2277 fps | 95.4% |
| Hodgdon Benchmark | <<locked>> | 80% | 49,429 psi | 76% | 2346 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 46,702 psi | 72% | 2385 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 80% | 51,677 psi | 80% | 2516 fps | 100% |
| Hodgdon H322 | <<locked>> | 80% | 54,636 psi | 84% | 2434 fps | 100% |
| Hodgdon H380 | <<locked>> | 80% | 39,102 psi | 60% | 2260 fps | 97.6% |
| Hodgdon H414 | <<locked>> | 86% | 38,551 psi | 59% | 2300 fps | 95.2% |
| Hodgdon H4350 | <<locked>> | 88% | 45,005 psi | 69% | 2369 fps | 95.5% |
| Hodgdon H4895 | <<locked>> | 80% | 46,195 psi | 71% | 2369 fps | 99.9% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 27,499 psi | 42% | 2037 fps | 96% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 42,264 psi | 65% | 2349 fps | 99.9% |
| Hodgdon Superformance | <<locked>> | 88% | 40,799 psi | 63% | 2365 fps | 95.2% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,687 psi | 41% | 1329 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 44,208 psi | 68% | 2326 fps | 99.8% |
| IMR 3031 | <<locked>> | 80% | 46,093 psi | 71% | 2356 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 40,901 psi | 63% | 2257 fps | 99% |
| IMR 4166 Enduron | <<locked>> | 80% | 43,323 psi | 67% | 2277 fps | 96.4% |
| IMR 4350 | <<locked>> | 90% | 41,916 psi | 64% | 2306 fps | 95.5% |
| IMR 4451 Enduron | <<locked>> | 84% | 40,770 psi | 63% | 2260 fps | 95.6% |
| IMR 4831 | <<locked>> | 82% | 30,589 psi | 47% | 2126 fps | 95.6% |
| IMR 4895 | <<locked>> | 80% | 42,467 psi | 65% | 2333 fps | 99.5% |
| IMR 8208 XBR | <<locked>> | 80% | 47,848 psi | 74% | 2362 fps | 100% |
| Lovex D073.5 | <<locked>> | 80% | 54,201 psi | 83% | 2434 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 44,904 psi | 69% | 2339 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 45,643 psi | 70% | 2300 fps | 99.8% |
| Lovex S062 | <<locked>> | 80% | 40,828 psi | 63% | 2260 fps | 99.8% |
| Lovex S065 | <<locked>> | 82% | 35,650 psi | 55% | 2169 fps | 95.7% |
| Lovex S070 | <<locked>> | 86% | 38,276 psi | 59% | 2241 fps | 95.3% |
| Norma 201 | <<locked>> | 80% | 44,860 psi | 69% | 2316 fps | 100% |
| Norma 202 | <<locked>> | 80% | 45,252 psi | 70% | 2320 fps | 100% |
| Norma 203B | <<locked>> | 80% | 40,814 psi | 63% | 2297 fps | 99.3% |
| Norma 204 | <<locked>> | 94% | 47,326 psi | 73% | 2431 fps | 95.4% |
| Norma MRP | <<locked>> | 98% | 41,553 psi | 64% | 2428 fps | 95.8% |
| Norma URP | <<locked>> | 82% | 31,952 psi | 49% | 2162 fps | 95.8% |
| Ramshot Big Game | <<locked>> | 80% | 40,306 psi | 62% | 2310 fps | 99.1% |
| Ramshot Hunter | <<locked>> | 86% | 35,447 psi | 55% | 2244 fps | 95% |
| Ramshot TAC | <<locked>> | 80% | 47,674 psi | 73% | 2375 fps | 98.7% |
| Ramshot Wild Boar | <<locked>> | 80% | 47,282 psi | 73% | 2392 fps | 99.9% |
| Ramshot X-Terminator | <<locked>> | 80% | 51,401 psi | 79% | 2405 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,006 psi | 42% | 1362 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 53,519 psi | 82% | 2428 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 39,349 psi | 61% | 2244 fps | 96% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 43,845 psi | 67% | 2402 fps | 99.4% |
| ReloadSwiss RS 60 | 53.4 gr | 80% | 35,476 psi | 55% | 2287 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 31,314 psi | 48% | 2175 fps | 95.3% |
| ReloadSwiss RS 70 | <<locked>> | 84% | 33,446 psi | 51% | 2224 fps | 95.1% |
| Rottweil R 901 | <<locked>> | 80% | 48,994 psi | 75% | 2343 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 42,757 psi | 66% | 2274 fps | 99.9% |
| Rottweil R 903 | <<locked>> | 80% | 36,013 psi | 55% | 2208 fps | 99% |
| Rottweil R 905 | <<locked>> | 98% | 44,121 psi | 68% | 2408 fps | 95.1% |
| Rottweil R 907 | <<locked>> | 86% | 41,727 psi | 64% | 2277 fps | 95.4% |
| Shooters World Long Rifle | <<locked>> | 82% | 35,650 psi | 55% | 2169 fps | 95.7% |
| Shooters World Match Rifle | <<locked>> | 80% | 44,904 psi | 69% | 2339 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 40,828 psi | 63% | 2260 fps | 99.8% |
| Shooters World SW4350 | <<locked>> | 86% | 38,276 psi | 59% | 2241 fps | 95.3% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 37,072 psi | 57% | 2254 fps | 98.6% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 46,021 psi | 71% | 2352 fps | 98.8% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 44,295 psi | 68% | 2336 fps | 99.6% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 46,079 psi | 71% | 2264 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 38,435 psi | 59% | 2152 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 39,639 psi | 61% | 2211 fps | 95.5% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 43,729 psi | 67% | 2402 fps | 95% |
| Somchem S321 | <<locked>> | 80% | 51,750 psi | 80% | 2431 fps | 100% |
| Somchem S335 | <<locked>> | 80% | 45,803 psi | 70% | 2267 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 45,818 psi | 70% | 2349 fps | 99.7% |
| Somchem S355 | <<locked>> | 80% | 36,912 psi | 57% | 2211 fps | 99% |
| Somchem S365 | <<locked>> | 80% | 26,803 psi | 41% | 2073 fps | 97.3% |
| Somchem S385 | <<locked>> | 96% | 41,785 psi | 64% | 2343 fps | 95.4% |
| Vihtavuori N130 | <<locked>> | 80% | 51,924 psi | 80% | 2310 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 46,456 psi | 71% | 2254 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 42,264 psi | 65% | 2251 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 42,685 psi | 66% | 2260 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 34,998 psi | 54% | 2156 fps | 99.4% |
| Vihtavuori N160 | <<locked>> | 80% | 31,212 psi | 48% | 2116 fps | 95.4% |
| Vihtavuori N530 | <<locked>> | 80% | 48,066 psi | 74% | 2359 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 41,162 psi | 63% | 2257 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 30,676 psi | 47% | 2119 fps | 95% |
| Vihtavuori N555 | <<locked>> | 88% | 29,631 psi | 46% | 2162 fps | 95.9% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 31,038 psi | 48% | 2100 fps | 97.6% |
| Winchester 748 | <<locked>> | 80% | 47,790 psi | 74% | 2402 fps | 100% |
| Winchester 760 | <<locked>> | 86% | 38,725 psi | 60% | 2303 fps | 95.3% |
| Winchester StaBALL HD | <<locked>> | 92% | 27,528 psi | 42% | 2162 fps | 96.2% |
| Winchester StaBALL Match | <<locked>> | 80% | 43,772 psi | 67% | 2339 fps | 99.8% |
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 106 powders for .338 Weatherby RPM loaded with the .338 | 250gr | Swift A-Frame. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 2,657 fps; across all powders the maximum-charge window runs from 1,490 fps to 2,657 fps. Accurate 3100 gives the best case fill at 100 %, and 106 of the 106 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (448 MPa), the top charges use 55–90 %, leaving at least 10 % headroom. The 250.0 gr projectile in 0.338" calls for a 1:15.5 twist; slower twists will usually not stabilise this weight. Accurate 3100, Accurate 4350, ADI AR 2209 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. Alliant Reloder-17, ReloadSwiss RS 60, Alliant Power Pro 2000-MR rank at the top here: for .338 Weatherby RPM with the .338 | 250gr | Swift A-Frame 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.