Load Specifications
Bullet Manufacturer:SAKO
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:1:6.0
Load data in caliber .338 Weatherby RPM with .338 | 250gr | Sako Hammerhead bullet and 110 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Power Pro 2000-MR, Hodgdon Superformance 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>> | 84% | 57,798 psi | 89% | 2425 fps | 100% |
| Accurate 2495 | <<locked>> | 88% | 56,855 psi | 87% | 2454 fps | 100% |
| Accurate 2520 | <<locked>> | 84% | 56,985 psi | 88% | 2510 fps | 100% |
| Accurate 2520 | <<locked>> | 84% | 56,985 psi | 88% | 2510 fps | 100% |
| Accurate 2700 | <<locked>> | 92% | 56,753 psi | 87% | 2480 fps | 98.4% |
| Accurate 3100ᴾ | <<locked>> | 100% | 43,627 psi | 67% | 2395 fps | 97.9% |
| Accurate 4064 | <<locked>> | 90% | 56,869 psi | 87% | 2503 fps | 100% |
| Accurate 4350 | <<locked>> | 98% | 56,884 psi | 88% | 2595 fps | 100% |
| ADI AR 2206H | <<locked>> | 86% | 57,000 psi | 88% | 2533 fps | 100% |
| ADI AR 2208 | <<locked>> | 92% | 58,030 psi | 89% | 2536 fps | 100% |
| ADI AR 2209ᴾ | <<locked>> | 100% | 51,459 psi | 79% | 2530 fps | 96.8% |
| ADI Benchmark 8208 | <<locked>> | 84% | 55,985 psi | 86% | 2487 fps | 100% |
| Alliant AR-Comp | <<locked>> | 84% | 57,348 psi | 88% | 2454 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 88% | 56,855 psi | 87% | 2651 fps | 100% |
| Alliant Power Pro Varmintᴾ | <<locked>> | 100% | 50,966 psi | 78% | 2526 fps | 96.8% |
| Alliant Reloder- TS 15.5 | <<locked>> | 92% | 58,276 psi | 90% | 2556 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 90% | 58,668 psi | 90% | 2575 fps | 100% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 57,754 psi | 89% | 2641 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 94% | 55,434 psi | 85% | 2625 fps | 100% |
| Alliant Reloder-19ᴾ | <<locked>> | 100% | 50,212 psi | 77% | 2516 fps | 96.7% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 41,510 psi | 64% | 2421 fps | 99.8% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 36,680 psi | 56% | 2336 fps | 96.4% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 46,543 psi | 72% | 2575 fps | 99.5% |
| Baschieri & Pellagri 107 | <<locked>> | 86% | 56,753 psi | 87% | 2552 fps | 100% |
| Bofors RP3 | <<locked>> | 90% | 55,434 psi | 85% | 2526 fps | 100% |
| Bofors RP7 | <<locked>> | 96% | 58,682 psi | 90% | 2552 fps | 98.9% |
| Hodgdon Benchmark | <<locked>> | 84% | 57,392 psi | 88% | 2464 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 84% | 55,405 psi | 85% | 2516 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 82% | 57,479 psi | 88% | 2608 fps | 100% |
| Hodgdon H322 | <<locked>> | 82% | 56,057 psi | 86% | 2464 fps | 100% |
| Hodgdon H380 | <<locked>> | 90% | 56,101 psi | 86% | 2539 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 94% | 57,334 psi | 88% | 2615 fps | 99.2% |
| Hodgdon H4350 | <<locked>> | 98% | 57,899 psi | 89% | 2579 fps | 98.3% |
| Hodgdon H4895 | <<locked>> | 86% | 57,638 psi | 89% | 2543 fps | 100% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 54,186 psi | 83% | 2530 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 90% | 57,261 psi | 88% | 2575 fps | 100% |
| Hodgdon Superformance | <<locked>> | 96% | 56,304 psi | 87% | 2635 fps | 98.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,737 psi | 55% | 1506 fps | 100% |
| Hodgdon VARGET | <<locked>> | 90% | 57,609 psi | 89% | 2526 fps | 100% |
| IMR 3031 | <<locked>> | 88% | 56,304 psi | 87% | 2497 fps | 100% |
| IMR 4064 | <<locked>> | 92% | 56,739 psi | 87% | 2510 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 92% | 55,985 psi | 86% | 2490 fps | 98.9% |
| IMR 4350 | <<locked>> | 98% | 55,637 psi | 86% | 2533 fps | 98.5% |
| IMR 4451 Enduron | <<locked>> | 94% | 57,000 psi | 88% | 2530 fps | 99% |
| IMR 4831ᴾ | <<locked>> | 100% | 50,879 psi | 78% | 2500 fps | 99.8% |
| IMR 4895 | <<locked>> | 88% | 56,637 psi | 87% | 2556 fps | 100% |
| IMR 8208 XBR | <<locked>> | 84% | 55,985 psi | 86% | 2487 fps | 100% |
| Lovex D073.6 | <<locked>> | 86% | 56,985 psi | 88% | 2510 fps | 100% |
| Lovex S060 | <<locked>> | 86% | 56,173 psi | 86% | 2464 fps | 100% |
| Lovex S062 | <<locked>> | 90% | 57,363 psi | 88% | 2513 fps | 100% |
| Lovex S065 | <<locked>> | 96% | 56,536 psi | 87% | 2526 fps | 99.7% |
| Lovex S070 | <<locked>> | 98% | 57,522 psi | 88% | 2559 fps | 99.2% |
| Lovex S071ᴾ | <<locked>> | 100% | 36,245 psi | 56% | 2264 fps | 95.9% |
| Norma 201 | <<locked>> | 86% | 55,593 psi | 86% | 2480 fps | 100% |
| Norma 202 | <<locked>> | 86% | 56,405 psi | 87% | 2480 fps | 100% |
| Norma 203B | <<locked>> | 90% | 57,899 psi | 89% | 2562 fps | 100% |
| Norma 204 | <<locked>> | 98% | 56,115 psi | 86% | 2579 fps | 97.6% |
| Norma MRPᴾ | <<locked>> | 100% | 46,325 psi | 71% | 2533 fps | 97.5% |
| Norma URP | <<locked>> | 98% | 55,637 psi | 86% | 2582 fps | 100% |
| Ramshot Big Game | <<locked>> | 90% | 58,726 psi | 90% | 2592 fps | 100% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 58,073 psi | 89% | 2631 fps | 99.7% |
| Ramshot TAC | <<locked>> | 84% | 55,985 psi | 86% | 2510 fps | 99.7% |
| Ramshot Wild Boar | <<locked>> | 84% | 55,883 psi | 86% | 2526 fps | 100% |
| Ramshot X-Terminator | <<locked>> | 82% | 56,623 psi | 87% | 2490 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,434 psi | 56% | 1545 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 82% | 58,813 psi | 90% | 2507 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 90% | 56,304 psi | 87% | 2526 fps | 99.3% |
| ReloadSwiss RS 52 | <<locked>> | 86% | 55,782 psi | 86% | 2589 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 92% | 55,129 psi | 85% | 2621 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 98% | 56,434 psi | 87% | 2618 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 98% | 55,637 psi | 86% | 2644 fps | 99.9% |
| Rottweil R 901 | <<locked>> | 84% | 56,782 psi | 87% | 2457 fps | 100% |
| Rottweil R 902 | <<locked>> | 88% | 56,188 psi | 86% | 2480 fps | 100% |
| Rottweil R 903 | <<locked>> | 92% | 55,288 psi | 85% | 2520 fps | 100% |
| Rottweil R 904ᴾ | <<locked>> | 100% | 53,171 psi | 82% | 2503 fps | 96% |
| Rottweil R 905ᴾ | <<locked>> | 100% | 48,994 psi | 75% | 2500 fps | 96.7% |
| Rottweil R 907 | <<locked>> | 96% | 58,682 psi | 90% | 2552 fps | 98.9% |
| Shooters World Long Rifle | <<locked>> | 96% | 56,536 psi | 87% | 2526 fps | 99.7% |
| Shooters World Match Rifle | <<locked>> | 86% | 56,985 psi | 88% | 2510 fps | 100% |
| Shooters World Precision | <<locked>> | 90% | 57,363 psi | 88% | 2513 fps | 100% |
| Shooters World SW4350 | <<locked>> | 98% | 57,522 psi | 88% | 2559 fps | 99.2% |
| SNPE Vectan SP 11 | <<locked>> | 92% | 56,869 psi | 87% | 2575 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 86% | 58,349 psi | 90% | 2539 fps | 99.9% |
| SNPE Vectan SP 9 | <<locked>> | 86% | 55,216 psi | 85% | 2510 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 86% | 57,087 psi | 88% | 2418 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 92% | 57,232 psi | 88% | 2418 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 96% | 56,710 psi | 87% | 2487 fps | 99% |
| SNPE Vectan Tubal 8000ᴾ | <<locked>> | 100% | 48,530 psi | 75% | 2497 fps | 96.6% |
| Somchem S321 | <<locked>> | 82% | 57,232 psi | 88% | 2516 fps | 100% |
| Somchem S335 | <<locked>> | 86% | 56,347 psi | 87% | 2418 fps | 100% |
| Somchem S341 | <<locked>> | 86% | 57,914 psi | 89% | 2530 fps | 100% |
| Somchem S355 | <<locked>> | 92% | 55,405 psi | 85% | 2513 fps | 100% |
| Somchem S365ᴾ | <<locked>> | 100% | 53,853 psi | 83% | 2582 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 49,719 psi | 76% | 2484 fps | 97.6% |
| Unknown powder | <<locked>> | 96% | 56,768 psi | 87% | 2589 fps | 99.9% |
| Vihtavuori N130 | <<locked>> | 82% | 56,782 psi | 87% | 2379 fps | 100% |
| Vihtavuori N133 | <<locked>> | 86% | 57,392 psi | 88% | 2402 fps | 100% |
| Vihtavuori N135 | <<locked>> | 88% | 56,057 psi | 86% | 2441 fps | 100% |
| Vihtavuori N140 | <<locked>> | 88% | 56,913 psi | 88% | 2461 fps | 100% |
| Vihtavuori N150 | <<locked>> | 94% | 56,898 psi | 88% | 2493 fps | 100% |
| Vihtavuori N160 | <<locked>> | 98% | 58,262 psi | 90% | 2575 fps | 100% |
| Vihtavuori N530 | <<locked>> | 84% | 56,478 psi | 87% | 2487 fps | 100% |
| Vihtavuori N540 | <<locked>> | 90% | 58,392 psi | 90% | 2503 fps | 100% |
| Vihtavuori N550 | <<locked>> | 98% | 57,130 psi | 88% | 2582 fps | 100% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 45,847 psi | 71% | 2487 fps | 99.8% |
| Winchester 6.5 StaBALL | <<locked>> | 98% | 58,247 psi | 90% | 2552 fps | 100% |
| Winchester 748 | <<locked>> | 82% | 57,217 psi | 88% | 2536 fps | 100% |
| Winchester 760 | <<locked>> | 94% | 57,334 psi | 88% | 2615 fps | 99.2% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 37,202 psi | 57% | 2444 fps | 99.9% |
| Winchester Supreme 780ᴾ | <<locked>> | 100% | 51,880 psi | 80% | 2503 fps | 96.8% |
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% | 51,227 psi | 79% | 2349 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 44,164 psi | 68% | 2293 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 49,748 psi | 77% | 2418 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 49,748 psi | 77% | 2418 fps | 100% |
| Accurate 2700 | <<locked>> | 82% | 41,075 psi | 63% | 2241 fps | 95.2% |
| Accurate 3100 | <<locked>> | 94% | 35,708 psi | 55% | 2251 fps | 95.7% |
| Accurate 4064 | <<locked>> | 80% | 41,771 psi | 64% | 2297 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 30,763 psi | 47% | 2152 fps | 95.9% |
| ADI AR 2206H | <<locked>> | 80% | 47,239 psi | 73% | 2395 fps | 99.9% |
| ADI AR 2208 | <<locked>> | 80% | 40,292 psi | 62% | 2270 fps | 98.9% |
| ADI AR 2209 | <<locked>> | 96% | 45,150 psi | 69% | 2428 fps | 95.2% |
| ADI Benchmark 8208 | <<locked>> | 80% | 49,313 psi | 76% | 2395 fps | 100% |
| Alliant AR-Comp | <<locked>> | 80% | 50,256 psi | 77% | 2372 fps | 100% |
| Alliant Power Pro 2000-MR | 56.3 gr | 80% | 43,279 psi | 67% | 2441 fps | 99.4% |
| Alliant Power Pro Varmint | <<locked>> | 96% | 45,063 psi | 69% | 2428 fps | 95.4% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 40,190 psi | 62% | 2290 fps | 99.7% |
| Alliant Reloder-15 | <<locked>> | 80% | 42,917 psi | 66% | 2346 fps | 99.4% |
| Alliant Reloder-16 | <<locked>> | 80% | 31,111 psi | 48% | 2165 fps | 96% |
| Alliant Reloder-17 | 55.4 gr | 80% | 34,635 psi | 53% | 2277 fps | 98.8% |
| Alliant Reloder-19 | <<locked>> | 96% | 44,454 psi | 68% | 2421 fps | 95.3% |
| Alliant Reloder-23 | <<locked>> | 86% | 27,021 psi | 42% | 2090 fps | 95.7% |
| Alliant Reloder-25 | <<locked>> | 98% | 34,490 psi | 53% | 2283 fps | 95.4% |
| Alliant Reloder-26 | <<locked>> | 90% | 32,866 psi | 51% | 2293 fps | 95.9% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 46,470 psi | 71% | 2405 fps | 99.5% |
| Bofors RP3 | <<locked>> | 80% | 39,885 psi | 61% | 2297 fps | 99.8% |
| Bofors RP7 | <<locked>> | 84% | 40,538 psi | 62% | 2270 fps | 95.3% |
| Hodgdon Benchmark | <<locked>> | 80% | 50,908 psi | 78% | 2382 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 48,530 psi | 75% | 2425 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 80% | 53,737 psi | 83% | 2559 fps | 100% |
| Hodgdon H322 | <<locked>> | 80% | 52,620 psi | 81% | 2421 fps | 100% |
| Hodgdon H380 | <<locked>> | 80% | 40,640 psi | 63% | 2300 fps | 98.2% |
| Hodgdon H414 | <<locked>> | 82% | 38,392 psi | 59% | 2310 fps | 95.5% |
| Hodgdon H4350 | <<locked>> | 88% | 42,583 psi | 66% | 2343 fps | 95.1% |
| Hodgdon H4895 | <<locked>> | 80% | 47,718 psi | 73% | 2405 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 28,616 psi | 44% | 2080 fps | 96.8% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 41,423 psi | 64% | 2346 fps | 99.9% |
| Hodgdon Superformance | 63 gr | 86% | 39,697 psi | 61% | 2359 fps | 95.2% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,745 psi | 41% | 1345 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 42,467 psi | 65% | 2306 fps | 99.8% |
| IMR 3031 | <<locked>> | 80% | 43,961 psi | 68% | 2336 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 39,552 psi | 61% | 2247 fps | 98.9% |
| IMR 4166 Enduron | <<locked>> | 80% | 39,233 psi | 60% | 2218 fps | 95.6% |
| IMR 4350 | <<locked>> | 88% | 40,785 psi | 63% | 2300 fps | 95.4% |
| IMR 4451 Enduron | <<locked>> | 82% | 39,639 psi | 61% | 2254 fps | 95.6% |
| IMR 4831 | <<locked>> | 82% | 28,993 psi | 45% | 2093 fps | 95.1% |
| IMR 4895 | <<locked>> | 80% | 44,005 psi | 68% | 2372 fps | 99.8% |
| IMR 8208 XBR | <<locked>> | 80% | 49,313 psi | 76% | 2395 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 46,688 psi | 72% | 2375 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 47,065 psi | 72% | 2336 fps | 99.9% |
| Lovex S062 | <<locked>> | 80% | 42,322 psi | 65% | 2297 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 34,838 psi | 54% | 2165 fps | 95.7% |
| Lovex S070 | <<locked>> | 84% | 37,449 psi | 58% | 2238 fps | 95.3% |
| Lovex S071 | <<locked>> | 98% | 34,098 psi | 52% | 2218 fps | 95.1% |
| Norma 201 | <<locked>> | 80% | 46,398 psi | 71% | 2352 fps | 100% |
| Norma 202 | <<locked>> | 80% | 46,833 psi | 72% | 2356 fps | 100% |
| Norma 203B | <<locked>> | 80% | 42,308 psi | 65% | 2336 fps | 99.6% |
| Norma 204 | <<locked>> | 92% | 45,919 psi | 71% | 2425 fps | 95.4% |
| Norma MRP | <<locked>> | 96% | 40,495 psi | 62% | 2425 fps | 95.8% |
| Norma URP | <<locked>> | 80% | 31,125 psi | 48% | 2156 fps | 95.8% |
| Ramshot Big Game | <<locked>> | 80% | 42,061 psi | 65% | 2352 fps | 99.5% |
| Ramshot Hunter | <<locked>> | 84% | 34,592 psi | 53% | 2241 fps | 95% |
| Ramshot TAC | <<locked>> | 80% | 49,298 psi | 76% | 2415 fps | 99.1% |
| Ramshot Wild Boar | <<locked>> | 80% | 48,834 psi | 75% | 2428 fps | 100% |
| Ramshot X-Terminator | <<locked>> | 80% | 53,098 psi | 82% | 2444 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,064 psi | 42% | 1375 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 55,332 psi | 85% | 2464 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 40,756 psi | 63% | 2283 fps | 96.7% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 45,455 psi | 70% | 2441 fps | 99.7% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 36,825 psi | 57% | 2329 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 30,429 psi | 47% | 2165 fps | 95.2% |
| ReloadSwiss RS 70 | <<locked>> | 82% | 32,619 psi | 50% | 2221 fps | 95.1% |
| Rottweil R 901 | <<locked>> | 80% | 50,459 psi | 78% | 2379 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 44,092 psi | 68% | 2310 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 37,463 psi | 58% | 2247 fps | 99.3% |
| Rottweil R 904 | <<locked>> | 98% | 49,922 psi | 77% | 2457 fps | 95.2% |
| Rottweil R 905 | <<locked>> | 96% | 43,062 psi | 66% | 2402 fps | 95.1% |
| Rottweil R 907 | <<locked>> | 84% | 40,538 psi | 62% | 2270 fps | 95.3% |
| Shooters World Long Rifle | <<locked>> | 80% | 34,838 psi | 54% | 2165 fps | 95.7% |
| Shooters World Match Rifle | <<locked>> | 80% | 46,688 psi | 72% | 2375 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 42,322 psi | 65% | 2297 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 37,449 psi | 58% | 2238 fps | 95.3% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 38,377 psi | 59% | 2290 fps | 99% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 47,776 psi | 74% | 2395 fps | 99.2% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 45,643 psi | 70% | 2372 fps | 99.8% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 47,427 psi | 73% | 2297 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 39,682 psi | 61% | 2185 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 38,653 psi | 59% | 2208 fps | 95.5% |
| SNPE Vectan Tubal 8000 | <<locked>> | 96% | 42,670 psi | 66% | 2398 fps | 95% |
| Somchem S321 | <<locked>> | 80% | 53,374 psi | 82% | 2467 fps | 100% |
| Somchem S335 | <<locked>> | 80% | 47,239 psi | 73% | 2300 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 47,282 psi | 73% | 2385 fps | 99.9% |
| Somchem S355 | <<locked>> | 80% | 38,334 psi | 59% | 2251 fps | 99.3% |
| Somchem S365 | <<locked>> | 80% | 27,905 psi | 43% | 2116 fps | 98% |
| Somchem S385 | <<locked>> | 94% | 40,930 psi | 63% | 2339 fps | 95.5% |
| Unknown powder | <<locked>> | 80% | 33,779 psi | 52% | 2205 fps | 96% |
| Vihtavuori N130 | <<locked>> | 80% | 53,403 psi | 82% | 2339 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 47,848 psi | 74% | 2287 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 43,772 psi | 67% | 2283 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 44,179 psi | 68% | 2293 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 36,332 psi | 56% | 2192 fps | 99.7% |
| Vihtavuori N160 | <<locked>> | 80% | 32,460 psi | 50% | 2156 fps | 96.2% |
| Vihtavuori N530 | <<locked>> | 80% | 49,574 psi | 76% | 2395 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 42,685 psi | 66% | 2293 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 32,024 psi | 49% | 2159 fps | 95.8% |
| Vihtavuori N555 | <<locked>> | 84% | 27,325 psi | 42% | 2110 fps | 95% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 32,053 psi | 49% | 2136 fps | 98.2% |
| Winchester 748 | <<locked>> | 80% | 53,229 psi | 82% | 2487 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 38,392 psi | 59% | 2310 fps | 95.5% |
| Winchester StaBALL HD | <<locked>> | 90% | 27,079 psi | 42% | 2165 fps | 96.4% |
| Winchester Supreme 780 | <<locked>> | 96% | 45,020 psi | 69% | 2398 fps | 95.2% |
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 110 powders for .338 Weatherby RPM loaded with the .338 | 250gr | Sako Hammerhead. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 2,651 fps; across all powders the maximum-charge window runs from 1,506 fps to 2,651 fps. Accurate 3100 gives the best case fill at 100 %, and 110 of the 110 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 1:6.0 twist; slower twists will usually not stabilise this weight. Accurate 3100, ADI AR 2209, Alliant Power Pro Varmint 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 Power Pro 2000-MR, Hodgdon Superformance, Alliant Reloder-17 rank at the top here: for .338 Weatherby RPM with the .338 | 250gr | Sako Hammerhead 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.