Load Specifications
Bullet Manufacturer:North Fork
Bullet Weight:225 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:1:15.0
Load data in caliber .338 Weatherby RPM with .338 | 225gr | NorthFork Bonded Core bullet and 107 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 ReloadSwiss RS 52.
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% | 55,695 psi | 86% | 2530 fps | 100% |
| Accurate 2460 | <<locked>> | 84% | 57,624 psi | 89% | 2602 fps | 100% |
| Accurate 2495 | <<locked>> | 92% | 57,174 psi | 88% | 2592 fps | 100% |
| Accurate 2520 | <<locked>> | 86% | 55,854 psi | 86% | 2615 fps | 100% |
| Accurate 2700 | <<locked>> | 92% | 57,058 psi | 88% | 2598 fps | 97.1% |
| Accurate 4064 | <<locked>> | 94% | 57,029 psi | 88% | 2635 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 52,663 psi | 81% | 2664 fps | 99.4% |
| Accurate LT-30 | <<locked>> | 82% | 57,870 psi | 89% | 2516 fps | 100% |
| Accurate LT-32 | <<locked>> | 82% | 58,305 psi | 90% | 2539 fps | 100% |
| ADI AR 2206H | <<locked>> | 90% | 57,914 psi | 89% | 2671 fps | 100% |
| ADI AR 2208 | <<locked>> | 94% | 55,390 psi | 85% | 2621 fps | 99.8% |
| ADI Benchmark 8208 | <<locked>> | 88% | 56,985 psi | 88% | 2621 fps | 100% |
| Alliant AR-Comp | <<locked>> | 88% | 57,769 psi | 89% | 2595 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 82% | 55,492 psi | 85% | 2677 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 92% | 57,798 psi | 89% | 2785 fps | 99.9% |
| Alliant Reloder- TS 15.5 | <<locked>> | 96% | 58,755 psi | 90% | 2687 fps | 100% |
| Alliant Reloder-10x | <<locked>> | 84% | 58,581 psi | 90% | 2569 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 92% | 55,854 psi | 86% | 2661 fps | 99.9% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 51,242 psi | 79% | 2667 fps | 99.5% |
| Alliant Reloder-17 | <<locked>> | 98% | 55,608 psi | 86% | 2753 fps | 100% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 36,463 psi | 56% | 2421 fps | 97.9% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 40,292 psi | 62% | 2559 fps | 96.8% |
| Baschieri & Pellagri 106 | <<locked>> | 82% | 57,043 psi | 88% | 2516 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 90% | 57,841 psi | 89% | 2687 fps | 99.8% |
| Bofors RP3 | <<locked>> | 94% | 55,869 psi | 86% | 2661 fps | 100% |
| Bofors RP7 | <<locked>> | 98% | 56,043 psi | 86% | 2625 fps | 97.3% |
| Hodgdon Benchmark | <<locked>> | 86% | 55,506 psi | 85% | 2562 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 88% | 56,275 psi | 87% | 2654 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 86% | 58,363 psi | 90% | 2749 fps | 100% |
| Hodgdon H322 | <<locked>> | 84% | 57,856 psi | 89% | 2615 fps | 100% |
| Hodgdon H335 | <<locked>> | 82% | 55,303 psi | 85% | 2598 fps | 100% |
| Hodgdon H380 | <<locked>> | 94% | 56,927 psi | 88% | 2671 fps | 99.4% |
| Hodgdon H414ᴾ | <<locked>> | 100% | 55,912 psi | 86% | 2713 fps | 98% |
| Hodgdon H4350 | <<locked>> | 98% | 56,898 psi | 88% | 2677 fps | 96.8% |
| Hodgdon H4895 | <<locked>> | 90% | 58,465 psi | 90% | 2677 fps | 100% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 47,471 psi | 73% | 2556 fps | 99.7% |
| Hodgdon LEVERevolution | <<locked>> | 92% | 57,667 psi | 89% | 2710 fps | 100% |
| Hodgdon Superformanceᴾ | <<locked>> | 100% | 57,145 psi | 88% | 2749 fps | 97.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,244 psi | 54% | 1568 fps | 100% |
| Hodgdon VARGET | <<locked>> | 90% | 56,231 psi | 87% | 2635 fps | 100% |
| IMR 3031 | <<locked>> | 90% | 58,465 psi | 90% | 2657 fps | 100% |
| IMR 4064 | <<locked>> | 94% | 58,378 psi | 90% | 2651 fps | 99.9% |
| IMR 4166 Enduron | <<locked>> | 90% | 55,288 psi | 85% | 2589 fps | 97.7% |
| IMR 4198 | <<locked>> | 84% | 58,581 psi | 90% | 2530 fps | 100% |
| IMR 4350ᴾ | <<locked>> | 100% | 52,634 psi | 81% | 2598 fps | 96.7% |
| IMR 4451 Enduron | <<locked>> | 98% | 58,015 psi | 89% | 2654 fps | 98% |
| IMR 4831ᴾ | <<locked>> | 100% | 49,966 psi | 77% | 2608 fps | 99.1% |
| IMR 4895 | <<locked>> | 92% | 57,246 psi | 88% | 2690 fps | 100% |
| IMR 8208 XBR | <<locked>> | 88% | 56,985 psi | 88% | 2621 fps | 100% |
| Lovex D073.5 | <<locked>> | 84% | 57,508 psi | 88% | 2615 fps | 100% |
| Lovex D073.6 | <<locked>> | 90% | 57,754 psi | 89% | 2648 fps | 100% |
| Lovex S060 | <<locked>> | 90% | 57,812 psi | 89% | 2602 fps | 100% |
| Lovex S062 | <<locked>> | 94% | 58,204 psi | 90% | 2648 fps | 100% |
| Lovex S065ᴾ | <<locked>> | 100% | 57,203 psi | 88% | 2651 fps | 99% |
| Lovex S070ᴾ | <<locked>> | 100% | 54,317 psi | 84% | 2631 fps | 97.8% |
| Norma 201 | <<locked>> | 90% | 56,768 psi | 87% | 2618 fps | 100% |
| Norma 202 | <<locked>> | 90% | 57,232 psi | 88% | 2618 fps | 100% |
| Norma 203B | <<locked>> | 94% | 58,610 psi | 90% | 2697 fps | 100% |
| Norma URPᴾ | <<locked>> | 100% | 51,953 psi | 80% | 2654 fps | 99.3% |
| Ramshot Big Game | <<locked>> | 92% | 55,622 psi | 86% | 2677 fps | 99.9% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 50,923 psi | 78% | 2648 fps | 97.9% |
| Ramshot TAC | <<locked>> | 88% | 57,624 psi | 89% | 2648 fps | 99.1% |
| Ramshot Wild Boar | <<locked>> | 88% | 56,971 psi | 88% | 2661 fps | 100% |
| Ramshot X-Terminator | <<locked>> | 86% | 58,291 psi | 90% | 2631 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 35,621 psi | 55% | 1604 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 84% | 56,608 psi | 87% | 2605 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 94% | 57,290 psi | 88% | 2651 fps | 98.5% |
| ReloadSwiss RS 52 | <<locked>> | 90% | 56,275 psi | 87% | 2726 fps | 99.9% |
| ReloadSwiss RS 60 | <<locked>> | 96% | 55,608 psi | 86% | 2756 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 52,272 psi | 80% | 2684 fps | 99.2% |
| ReloadSwiss RS 70ᴾ | <<locked>> | 100% | 52,518 psi | 81% | 2710 fps | 99% |
| Rottweil R 901 | <<locked>> | 88% | 57,682 psi | 89% | 2598 fps | 100% |
| Rottweil R 902 | <<locked>> | 92% | 57,116 psi | 88% | 2615 fps | 100% |
| Rottweil R 903 | <<locked>> | 96% | 55,448 psi | 85% | 2648 fps | 100% |
| Rottweil R 907 | <<locked>> | 98% | 56,043 psi | 86% | 2625 fps | 97.3% |
| Shooters World Long Rifleᴾ | <<locked>> | 100% | 57,203 psi | 88% | 2651 fps | 99% |
| Shooters World Match Rifle | <<locked>> | 90% | 57,754 psi | 89% | 2648 fps | 100% |
| Shooters World Precision | <<locked>> | 94% | 58,204 psi | 90% | 2648 fps | 100% |
| Shooters World SW4350ᴾ | <<locked>> | 100% | 54,317 psi | 84% | 2631 fps | 97.8% |
| Shooters World Tactical Rifle | <<locked>> | 82% | 56,333 psi | 87% | 2579 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 96% | 57,363 psi | 88% | 2707 fps | 100% |
| SNPE Vectan SP 3 | <<locked>> | 82% | 56,101 psi | 86% | 2549 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 88% | 55,970 psi | 86% | 2625 fps | 99.3% |
| SNPE Vectan SP 9 | <<locked>> | 90% | 56,347 psi | 87% | 2644 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 90% | 58,595 psi | 90% | 2559 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 96% | 58,305 psi | 90% | 2556 fps | 100% |
| SNPE Vectan Tubal 7000ᴾ | <<locked>> | 100% | 57,885 psi | 89% | 2605 fps | 98% |
| Somchem S321 | <<locked>> | 86% | 58,668 psi | 90% | 2661 fps | 100% |
| Somchem S335 | <<locked>> | 90% | 57,725 psi | 89% | 2559 fps | 100% |
| Somchem S341 | <<locked>> | 88% | 55,245 psi | 85% | 2615 fps | 99.9% |
| Somchem S355 | <<locked>> | 96% | 55,738 psi | 86% | 2644 fps | 100% |
| Somchem S365ᴾ | <<locked>> | 100% | 46,514 psi | 72% | 2608 fps | 100% |
| Vihtavuori N130 | <<locked>> | 86% | 58,363 psi | 90% | 2523 fps | 100% |
| Vihtavuori N133 | <<locked>> | 90% | 58,639 psi | 90% | 2543 fps | 100% |
| Vihtavuori N135 | <<locked>> | 92% | 56,652 psi | 87% | 2579 fps | 100% |
| Vihtavuori N140 | <<locked>> | 92% | 57,827 psi | 89% | 2598 fps | 100% |
| Vihtavuori N150 | <<locked>> | 98% | 57,537 psi | 89% | 2625 fps | 100% |
| Vihtavuori N160ᴾ | <<locked>> | 100% | 54,592 psi | 84% | 2648 fps | 99.4% |
| Vihtavuori N530 | <<locked>> | 88% | 57,870 psi | 89% | 2628 fps | 100% |
| Vihtavuori N540 | <<locked>> | 92% | 55,825 psi | 86% | 2598 fps | 100% |
| Vihtavuori N550ᴾ | <<locked>> | 100% | 53,534 psi | 82% | 2654 fps | 99.3% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 39,247 psi | 60% | 2490 fps | 97.8% |
| Winchester 6.5 StaBALLᴾ | <<locked>> | 100% | 55,317 psi | 85% | 2635 fps | 100% |
| Winchester 748 | <<locked>> | 88% | 57,464 psi | 88% | 2671 fps | 100% |
| Winchester 760ᴾ | <<locked>> | 100% | 56,188 psi | 86% | 2717 fps | 98% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 32,416 psi | 50% | 2402 fps | 97.1% |
| Winchester StaBALL Match | <<locked>> | 90% | 56,304 psi | 87% | 2654 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% | 46,267 psi | 71% | 2405 fps | 100% |
| Accurate 2460 | <<locked>> | 80% | 50,473 psi | 78% | 2510 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 38,827 psi | 60% | 2336 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 45,513 psi | 70% | 2470 fps | 100% |
| Accurate 2700 | <<locked>> | 86% | 46,992 psi | 72% | 2448 fps | 95% |
| Accurate 4064 | <<locked>> | 80% | 36,738 psi | 57% | 2329 fps | 100% |
| Accurate 4350 | <<locked>> | 88% | 34,824 psi | 54% | 2352 fps | 95.7% |
| Accurate LT-30 | <<locked>> | 80% | 54,317 psi | 84% | 2470 fps | 100% |
| Accurate LT-32 | <<locked>> | 80% | 54,752 psi | 84% | 2497 fps | 100% |
| ADI AR 2206H | <<locked>> | 80% | 42,467 psi | 65% | 2431 fps | 98.8% |
| ADI AR 2208 | <<locked>> | 80% | 36,172 psi | 56% | 2293 fps | 96.7% |
| ADI Benchmark 8208 | <<locked>> | 80% | 44,512 psi | 68% | 2438 fps | 99.7% |
| Alliant AR-Comp | <<locked>> | 80% | 44,353 psi | 68% | 2428 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 80% | 51,924 psi | 80% | 2625 fps | 100% |
| Alliant Power Pro 2000-MR | 54.7 gr | 80% | 38,493 psi | 59% | 2454 fps | 97.2% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 35,665 psi | 55% | 2313 fps | 98.1% |
| Alliant Reloder-10x | <<locked>> | 80% | 51,982 psi | 80% | 2490 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 38,276 psi | 59% | 2369 fps | 97.5% |
| Alliant Reloder-16 | <<locked>> | 88% | 35,563 psi | 55% | 2369 fps | 95.9% |
| Alliant Reloder-17 | <<locked>> | 80% | 30,647 psi | 47% | 2274 fps | 95.7% |
| Alliant Reloder-23 | <<locked>> | 94% | 30,414 psi | 47% | 2274 fps | 95.4% |
| Alliant Reloder-26 | <<locked>> | 98% | 37,550 psi | 58% | 2497 fps | 95.7% |
| Baschieri & Pellagri 106 | <<locked>> | 80% | 53,476 psi | 82% | 2470 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 41,481 psi | 64% | 2431 fps | 97.7% |
| Bofors RP3 | <<locked>> | 80% | 35,128 psi | 54% | 2316 fps | 98.1% |
| Bofors RP7 | <<locked>> | 92% | 46,528 psi | 72% | 2480 fps | 95.2% |
| Hodgdon Benchmark | <<locked>> | 80% | 46,354 psi | 71% | 2428 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 43,163 psi | 66% | 2461 fps | 99.8% |
| Hodgdon CFE223 | <<locked>> | 80% | 47,282 psi | 73% | 2585 fps | 99.2% |
| Hodgdon H322 | <<locked>> | 80% | 51,039 psi | 79% | 2526 fps | 100% |
| Hodgdon H335 | <<locked>> | 80% | 51,648 psi | 79% | 2549 fps | 100% |
| Hodgdon H380 | <<locked>> | 80% | 35,984 psi | 55% | 2313 fps | 95.4% |
| Hodgdon H414 | <<locked>> | 92% | 43,149 psi | 66% | 2507 fps | 95.2% |
| Hodgdon H4350 | <<locked>> | 94% | 50,372 psi | 77% | 2579 fps | 95.4% |
| Hodgdon H4895 | <<locked>> | 80% | 42,801 psi | 66% | 2441 fps | 99.2% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 30,589 psi | 47% | 2224 fps | 95.9% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 38,682 psi | 60% | 2415 fps | 98.9% |
| Hodgdon Superformance | <<locked>> | 94% | 46,340 psi | 71% | 2582 fps | 95.2% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,266 psi | 40% | 1401 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 41,075 psi | 63% | 2395 fps | 98.9% |
| IMR 3031 | <<locked>> | 80% | 42,351 psi | 65% | 2438 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 37,956 psi | 58% | 2323 fps | 97.5% |
| IMR 4166 Enduron | <<locked>> | 82% | 43,076 psi | 66% | 2392 fps | 95% |
| IMR 4198 | <<locked>> | 80% | 52,214 psi | 80% | 2451 fps | 100% |
| IMR 4350 | <<locked>> | 96% | 46,383 psi | 71% | 2500 fps | 95.2% |
| IMR 4451 Enduron | <<locked>> | 90% | 45,484 psi | 70% | 2464 fps | 95.5% |
| IMR 4831 | <<locked>> | 88% | 33,939 psi | 52% | 2316 fps | 95.4% |
| IMR 4895 | <<locked>> | 80% | 39,146 psi | 60% | 2398 fps | 98.2% |
| IMR 8208 XBR | <<locked>> | 80% | 44,512 psi | 68% | 2438 fps | 99.7% |
| Lovex D073.5 | <<locked>> | 80% | 50,343 psi | 77% | 2520 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 41,394 psi | 64% | 2415 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 42,743 psi | 66% | 2375 fps | 98.8% |
| Lovex S062 | <<locked>> | 80% | 37,782 psi | 58% | 2329 fps | 98.9% |
| Lovex S065 | <<locked>> | 88% | 39,624 psi | 61% | 2365 fps | 95.6% |
| Lovex S070 | <<locked>> | 92% | 42,583 psi | 66% | 2441 fps | 95.2% |
| Norma 201 | <<locked>> | 80% | 41,669 psi | 64% | 2388 fps | 99.5% |
| Norma 202 | <<locked>> | 80% | 41,901 psi | 64% | 2398 fps | 100% |
| Norma 203B | <<locked>> | 80% | 37,666 psi | 58% | 2359 fps | 97.9% |
| Norma URP | <<locked>> | 88% | 35,360 psi | 54% | 2356 fps | 95.7% |
| Ramshot Big Game | <<locked>> | 80% | 37,115 psi | 57% | 2372 fps | 97.5% |
| Ramshot Hunter | <<locked>> | 94% | 42,119 psi | 65% | 2497 fps | 95.8% |
| Ramshot TAC | <<locked>> | 80% | 44,324 psi | 68% | 2441 fps | 97% |
| Ramshot Wild Boar | <<locked>> | 80% | 43,700 psi | 67% | 2461 fps | 99% |
| Ramshot X-Terminator | <<locked>> | 80% | 48,109 psi | 74% | 2484 fps | 99.4% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,513 psi | 41% | 1434 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 49,893 psi | 77% | 2513 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 41,481 psi | 64% | 2402 fps | 95.3% |
| ReloadSwiss RS 52 | 53 gr | 80% | 39,900 psi | 61% | 2461 fps | 97.9% |
| ReloadSwiss RS 60 | 53.8 gr | 80% | 32,634 psi | 50% | 2339 fps | 98.9% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 34,664 psi | 53% | 2369 fps | 95.2% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 37,623 psi | 58% | 2431 fps | 95.2% |
| Rottweil R 901 | <<locked>> | 80% | 45,716 psi | 70% | 2428 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 39,769 psi | 61% | 2346 fps | 99.2% |
| Rottweil R 903 | <<locked>> | 80% | 33,083 psi | 51% | 2264 fps | 97.3% |
| Rottweil R 907 | <<locked>> | 92% | 46,528 psi | 72% | 2480 fps | 95.2% |
| Shooters World Long Rifle | <<locked>> | 88% | 39,624 psi | 61% | 2365 fps | 95.6% |
| Shooters World Match Rifle | <<locked>> | 80% | 41,394 psi | 64% | 2415 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 37,782 psi | 58% | 2329 fps | 98.9% |
| Shooters World SW4350 | <<locked>> | 92% | 42,583 psi | 66% | 2441 fps | 95.2% |
| Shooters World Tactical Rifle | <<locked>> | 80% | 52,794 psi | 81% | 2533 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 34,011 psi | 52% | 2310 fps | 96.6% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 52,779 psi | 81% | 2510 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 42,670 psi | 66% | 2418 fps | 97.2% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 40,973 psi | 63% | 2402 fps | 98.5% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 43,091 psi | 66% | 2346 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 35,708 psi | 55% | 2224 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 92% | 44,396 psi | 68% | 2411 fps | 95.4% |
| Somchem S321 | <<locked>> | 80% | 47,964 psi | 74% | 2513 fps | 100% |
| Somchem S335 | <<locked>> | 80% | 42,714 psi | 66% | 2349 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 42,235 psi | 65% | 2415 fps | 98.7% |
| Somchem S355 | <<locked>> | 80% | 33,982 psi | 52% | 2270 fps | 97.3% |
| Somchem S365 | <<locked>> | 82% | 26,179 psi | 40% | 2159 fps | 95.3% |
| Vihtavuori N130 | <<locked>> | 80% | 48,704 psi | 75% | 2402 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 43,366 psi | 67% | 2343 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 38,885 psi | 60% | 2329 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 39,726 psi | 61% | 2339 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 32,343 psi | 50% | 2215 fps | 98.1% |
| Vihtavuori N160 | <<locked>> | 86% | 34,853 psi | 54% | 2310 fps | 95.4% |
| Vihtavuori N530 | <<locked>> | 80% | 44,614 psi | 69% | 2438 fps | 99.7% |
| Vihtavuori N540 | <<locked>> | 80% | 38,058 psi | 59% | 2329 fps | 99.9% |
| Vihtavuori N550 | <<locked>> | 88% | 36,463 psi | 56% | 2362 fps | 95.8% |
| Vihtavuori N555 | <<locked>> | 94% | 32,358 psi | 50% | 2343 fps | 95.5% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 28,674 psi | 44% | 2139 fps | 95% |
| Winchester 748 | <<locked>> | 80% | 43,932 psi | 68% | 2477 fps | 99.9% |
| Winchester 760 | <<locked>> | 92% | 43,149 psi | 66% | 2507 fps | 95.2% |
| Winchester StaBALL HD | <<locked>> | 98% | 30,472 psi | 47% | 2343 fps | 95.9% |
| Winchester StaBALL Match | <<locked>> | 80% | 40,277 psi | 62% | 2405 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 107 powders for .338 Weatherby RPM loaded with the .338 | 225gr | NorthFork Bonded Core. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 2,785 fps; across all powders the maximum-charge window runs from 1,568 fps to 2,785 fps. Accurate 4350 gives the best case fill at 100 %, and 107 of the 107 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (448 MPa), the top charges use 50–90 %, leaving at least 10 % headroom. The 225.0 gr projectile in 0.338" calls for a 1:15.0 twist; slower twists will usually not stabilise this weight. Accurate 4350, Alliant Reloder-16, Alliant Reloder-23 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, ReloadSwiss RS 52 rank at the top here: for .338 Weatherby RPM with the .338 | 225gr | NorthFork Bonded Core 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.