Load Specifications
Bullet Manufacturer:Sierra
Bullet Weight:215 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 | 215gr | Sierra GameKing 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 Power Pro 2000-MR, ReloadSwiss RS 60 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>> | 88% | 58,218 psi | 90% | 2631 fps | 100% |
| Accurate 2460 | <<locked>> | 84% | 56,869 psi | 87% | 2661 fps | 100% |
| Accurate 2495 | <<locked>> | 92% | 56,217 psi | 86% | 2651 fps | 100% |
| Accurate 2520 | <<locked>> | 86% | 54,998 psi | 85% | 2674 fps | 100% |
| Accurate 2700 | <<locked>> | 92% | 56,304 psi | 87% | 2651 fps | 96.6% |
| Accurate 4064 | <<locked>> | 94% | 56,028 psi | 86% | 2694 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 51,866 psi | 80% | 2720 fps | 99.1% |
| Accurate LT-30 | <<locked>> | 82% | 57,087 psi | 88% | 2572 fps | 100% |
| Accurate LT-32 | <<locked>> | 82% | 57,522 psi | 88% | 2602 fps | 100% |
| ADI AR 2206H | <<locked>> | 90% | 57,087 psi | 88% | 2726 fps | 99.9% |
| ADI AR 2208 | <<locked>> | 96% | 58,059 psi | 89% | 2723 fps | 99.8% |
| ADI AR 2219 | <<locked>> | 82% | 58,436 psi | 90% | 2694 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 88% | 56,275 psi | 87% | 2680 fps | 100% |
| Alliant AR-Comp | <<locked>> | 88% | 56,768 psi | 87% | 2657 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 84% | 58,291 psi | 90% | 2785 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 92% | 56,826 psi | 87% | 2844 fps | 99.8% |
| Alliant Reloder- TS 15.5 | <<locked>> | 96% | 57,986 psi | 89% | 2746 fps | 100% |
| Alliant Reloder-10x | <<locked>> | 84% | 57,943 psi | 89% | 2635 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 94% | 58,755 psi | 90% | 2769 fps | 99.9% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 50,430 psi | 78% | 2720 fps | 99.2% |
| Alliant Reloder-17ᴾ | <<locked>> | 100% | 58,668 psi | 90% | 2864 fps | 100% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 35,868 psi | 55% | 2467 fps | 97.3% |
| Baschieri & Pellagri 106 | <<locked>> | 82% | 56,405 psi | 87% | 2575 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 90% | 56,985 psi | 88% | 2743 fps | 99.6% |
| Bofors RP3 | <<locked>> | 96% | 58,682 psi | 90% | 2766 fps | 100% |
| Bofors RP7 | <<locked>> | 98% | 55,288 psi | 85% | 2680 fps | 96.8% |
| Hodgdon Benchmark | <<locked>> | 88% | 58,407 psi | 90% | 2667 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 88% | 55,506 psi | 85% | 2713 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 86% | 57,595 psi | 89% | 2808 fps | 99.9% |
| Hodgdon H322 | <<locked>> | 84% | 57,014 psi | 88% | 2674 fps | 100% |
| Hodgdon H335 | <<locked>> | 84% | 58,349 psi | 90% | 2707 fps | 100% |
| Hodgdon H380 | <<locked>> | 94% | 56,101 psi | 86% | 2726 fps | 99.2% |
| Hodgdon H414ᴾ | <<locked>> | 100% | 55,042 psi | 85% | 2766 fps | 97.5% |
| Hodgdon H4350 | <<locked>> | 98% | 56,275 psi | 87% | 2733 fps | 96.3% |
| Hodgdon H4895 | <<locked>> | 90% | 57,696 psi | 89% | 2736 fps | 100% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 46,673 psi | 72% | 2608 fps | 99.5% |
| Hodgdon LEVERevolution | <<locked>> | 92% | 56,768 psi | 87% | 2769 fps | 100% |
| Hodgdon Superformanceᴾ | <<locked>> | 100% | 56,289 psi | 87% | 2805 fps | 97.1% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,172 psi | 54% | 1614 fps | 100% |
| Hodgdon VARGET | <<locked>> | 90% | 55,724 psi | 86% | 2694 fps | 100% |
| IMR 3031 | <<locked>> | 90% | 57,653 psi | 89% | 2723 fps | 100% |
| IMR 4064 | <<locked>> | 94% | 57,798 psi | 89% | 2710 fps | 99.9% |
| IMR 4166 Enduron | <<locked>> | 92% | 57,972 psi | 89% | 2690 fps | 97.7% |
| IMR 4198 | <<locked>> | 84% | 57,885 psi | 89% | 2592 fps | 100% |
| IMR 4350ᴾ | <<locked>> | 100% | 51,706 psi | 80% | 2651 fps | 96.1% |
| IMR 4451 Enduron | <<locked>> | 98% | 57,217 psi | 88% | 2710 fps | 97.6% |
| IMR 4831ᴾ | <<locked>> | 100% | 49,240 psi | 76% | 2661 fps | 98.8% |
| IMR 4895 | <<locked>> | 92% | 56,579 psi | 87% | 2749 fps | 99.9% |
| IMR 8208 XBR | <<locked>> | 88% | 56,275 psi | 87% | 2680 fps | 100% |
| Lovex D073.5 | <<locked>> | 84% | 56,652 psi | 87% | 2671 fps | 100% |
| Lovex D073.6 | <<locked>> | 90% | 56,695 psi | 87% | 2707 fps | 100% |
| Lovex S060 | <<locked>> | 90% | 56,927 psi | 88% | 2657 fps | 99.9% |
| Lovex S062 | <<locked>> | 94% | 57,305 psi | 88% | 2707 fps | 100% |
| Lovex S065ᴾ | <<locked>> | 100% | 56,304 psi | 87% | 2703 fps | 98.6% |
| Lovex S070ᴾ | <<locked>> | 100% | 53,650 psi | 83% | 2684 fps | 97.3% |
| Norma 201 | <<locked>> | 90% | 56,028 psi | 86% | 2677 fps | 100% |
| Norma 202 | <<locked>> | 90% | 56,478 psi | 87% | 2680 fps | 100% |
| Norma 203B | <<locked>> | 94% | 57,812 psi | 89% | 2756 fps | 100% |
| Norma URPᴾ | <<locked>> | 100% | 51,213 psi | 79% | 2707 fps | 99% |
| Ramshot Big Game | <<locked>> | 94% | 58,494 psi | 90% | 2782 fps | 100% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 50,140 psi | 77% | 2697 fps | 97.4% |
| Ramshot TAC | <<locked>> | 88% | 56,681 psi | 87% | 2703 fps | 98.8% |
| Ramshot Wild Boar | <<locked>> | 88% | 56,217 psi | 86% | 2720 fps | 99.9% |
| Ramshot X-Terminator | <<locked>> | 86% | 57,464 psi | 88% | 2687 fps | 99.9% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 35,520 psi | 55% | 1650 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 84% | 55,999 psi | 86% | 2667 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 94% | 56,420 psi | 87% | 2707 fps | 98.1% |
| ReloadSwiss RS 52 | <<locked>> | 90% | 55,463 psi | 85% | 2785 fps | 99.7% |
| ReloadSwiss RS 60 | <<locked>> | 98% | 58,436 psi | 90% | 2864 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 51,242 psi | 79% | 2736 fps | 98.9% |
| ReloadSwiss RS 70ᴾ | <<locked>> | 100% | 51,851 psi | 80% | 2762 fps | 98.6% |
| Rottweil R 901 | <<locked>> | 88% | 56,855 psi | 87% | 2657 fps | 100% |
| Rottweil R 902 | <<locked>> | 92% | 56,376 psi | 87% | 2674 fps | 100% |
| Rottweil R 903 | <<locked>> | 98% | 58,247 psi | 90% | 2749 fps | 100% |
| Rottweil R 907 | <<locked>> | 98% | 55,288 psi | 85% | 2680 fps | 96.8% |
| Shooters World Long Rifleᴾ | <<locked>> | 100% | 56,304 psi | 87% | 2703 fps | 98.6% |
| Shooters World Match Rifle | <<locked>> | 90% | 56,695 psi | 87% | 2707 fps | 100% |
| Shooters World Precision | <<locked>> | 94% | 57,305 psi | 88% | 2707 fps | 100% |
| Shooters World SW4350ᴾ | <<locked>> | 100% | 53,650 psi | 83% | 2684 fps | 97.3% |
| Shooters World Tactical Rifle | <<locked>> | 82% | 55,666 psi | 86% | 2638 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 96% | 56,347 psi | 87% | 2762 fps | 99.9% |
| SNPE Vectan SP 3 | <<locked>> | 82% | 55,521 psi | 85% | 2615 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 90% | 58,813 psi | 90% | 2730 fps | 99.3% |
| SNPE Vectan SP 9 | <<locked>> | 90% | 55,709 psi | 86% | 2703 fps | 99.9% |
| SNPE Vectan Tubal 3000 | <<locked>> | 90% | 57,740 psi | 89% | 2618 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 96% | 57,812 psi | 89% | 2615 fps | 100% |
| SNPE Vectan Tubal 7000ᴾ | <<locked>> | 100% | 56,913 psi | 88% | 2657 fps | 97.5% |
| Somchem S321 | <<locked>> | 86% | 57,711 psi | 89% | 2720 fps | 100% |
| Somchem S335 | <<locked>> | 90% | 57,029 psi | 88% | 2618 fps | 100% |
| Somchem S341 | <<locked>> | 90% | 58,262 psi | 90% | 2723 fps | 99.9% |
| Somchem S355 | <<locked>> | 98% | 58,610 psi | 90% | 2749 fps | 100% |
| Somchem S365ᴾ | <<locked>> | 100% | 45,614 psi | 70% | 2657 fps | 100% |
| Vihtavuori N130 | <<locked>> | 86% | 57,711 psi | 89% | 2585 fps | 100% |
| Vihtavuori N133 | <<locked>> | 90% | 57,798 psi | 89% | 2602 fps | 100% |
| Vihtavuori N135 | <<locked>> | 92% | 55,869 psi | 86% | 2641 fps | 100% |
| Vihtavuori N140 | <<locked>> | 92% | 56,927 psi | 88% | 2657 fps | 100% |
| Vihtavuori N150 | <<locked>> | 98% | 56,652 psi | 87% | 2684 fps | 100% |
| Vihtavuori N160ᴾ | <<locked>> | 100% | 53,867 psi | 83% | 2707 fps | 99.2% |
| Vihtavuori N530 | <<locked>> | 88% | 57,101 psi | 88% | 2684 fps | 100% |
| Vihtavuori N540 | <<locked>> | 94% | 58,581 psi | 90% | 2700 fps | 100% |
| Vihtavuori N550ᴾ | <<locked>> | 100% | 52,750 psi | 81% | 2710 fps | 99% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 38,406 psi | 59% | 2536 fps | 97.2% |
| Winchester 6.5 StaBALLᴾ | <<locked>> | 100% | 54,636 psi | 84% | 2690 fps | 100% |
| Winchester 748 | <<locked>> | 88% | 56,521 psi | 87% | 2730 fps | 100% |
| Winchester 760ᴾ | <<locked>> | 100% | 55,317 psi | 85% | 2769 fps | 97.5% |
| Winchester StaBALL Match | <<locked>> | 90% | 55,550 psi | 85% | 2713 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% | 45,614 psi | 70% | 2461 fps | 100% |
| Accurate 2460 | <<locked>> | 80% | 49,719 psi | 76% | 2566 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 38,101 psi | 59% | 2385 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 44,759 psi | 69% | 2523 fps | 100% |
| Accurate 2700 | <<locked>> | 88% | 49,269 psi | 76% | 2546 fps | 95.2% |
| Accurate 4064 | <<locked>> | 80% | 36,042 psi | 55% | 2375 fps | 99.8% |
| Accurate 4350 | <<locked>> | 88% | 34,200 psi | 53% | 2398 fps | 95% |
| Accurate LT-30 | <<locked>> | 80% | 53,635 psi | 83% | 2530 fps | 100% |
| Accurate LT-32 | <<locked>> | 80% | 54,041 psi | 83% | 2556 fps | 100% |
| ADI AR 2206H | <<locked>> | 80% | 41,945 psi | 65% | 2484 fps | 98.4% |
| ADI AR 2208 | <<locked>> | 80% | 35,592 psi | 55% | 2339 fps | 96.1% |
| ADI AR 2219 | <<locked>> | 80% | 54,839 psi | 84% | 2648 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 80% | 43,947 psi | 68% | 2493 fps | 99.5% |
| Alliant AR-Comp | <<locked>> | 80% | 43,801 psi | 67% | 2487 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 80% | 51,242 psi | 79% | 2684 fps | 99.9% |
| Alliant Power Pro 2000-MR | 55.9 gr | 80% | 37,826 psi | 58% | 2497 fps | 96.5% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 34,998 psi | 54% | 2359 fps | 97.6% |
| Alliant Reloder-10x | <<locked>> | 80% | 51,285 psi | 79% | 2549 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 37,753 psi | 58% | 2418 fps | 97% |
| Alliant Reloder-16 | <<locked>> | 88% | 34,940 psi | 54% | 2408 fps | 95.1% |
| Alliant Reloder-17 | <<locked>> | 80% | 30,269 psi | 47% | 2320 fps | 95% |
| Alliant Reloder-23 | <<locked>> | 96% | 31,749 psi | 49% | 2362 fps | 95.6% |
| Baschieri & Pellagri 106 | <<locked>> | 80% | 53,011 psi | 82% | 2533 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 40,930 psi | 63% | 2484 fps | 97.2% |
| Bofors RP3 | <<locked>> | 80% | 34,592 psi | 53% | 2362 fps | 97.6% |
| Bofors RP7 | <<locked>> | 94% | 48,762 psi | 75% | 2579 fps | 95.4% |
| Hodgdon Benchmark | <<locked>> | 80% | 45,861 psi | 71% | 2484 fps | 99.9% |
| Hodgdon BL-C2 | <<locked>> | 80% | 42,380 psi | 65% | 2510 fps | 99.6% |
| Hodgdon CFE223 | <<locked>> | 80% | 46,601 psi | 72% | 2641 fps | 98.9% |
| Hodgdon H322 | <<locked>> | 80% | 50,111 psi | 77% | 2585 fps | 100% |
| Hodgdon H335 | <<locked>> | 80% | 51,097 psi | 79% | 2608 fps | 100% |
| Hodgdon H380 | <<locked>> | 82% | 37,942 psi | 58% | 2415 fps | 95.6% |
| Hodgdon H414 | <<locked>> | 94% | 45,252 psi | 70% | 2608 fps | 95.3% |
| Hodgdon H4350 | <<locked>> | 96% | 52,852 psi | 81% | 2680 fps | 95.6% |
| Hodgdon H4895 | <<locked>> | 80% | 42,293 psi | 65% | 2493 fps | 98.9% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 30,110 psi | 46% | 2267 fps | 95.2% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 38,058 psi | 59% | 2461 fps | 98.5% |
| Hodgdon Superformance | <<locked>> | 96% | 48,805 psi | 75% | 2684 fps | 95.4% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,194 psi | 40% | 1440 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 40,582 psi | 62% | 2448 fps | 98.5% |
| IMR 3031 | <<locked>> | 80% | 41,582 psi | 64% | 2490 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 37,347 psi | 57% | 2369 fps | 96.9% |
| IMR 4166 Enduron | <<locked>> | 84% | 45,208 psi | 70% | 2490 fps | 95.1% |
| IMR 4198 | <<locked>> | 80% | 51,692 psi | 80% | 2513 fps | 100% |
| IMR 4350 | <<locked>> | 98% | 48,602 psi | 75% | 2598 fps | 95.4% |
| IMR 4451 Enduron | <<locked>> | 92% | 47,688 psi | 73% | 2562 fps | 95.7% |
| IMR 4831 | <<locked>> | 90% | 35,578 psi | 55% | 2411 fps | 95.6% |
| IMR 4895 | <<locked>> | 80% | 38,609 psi | 59% | 2448 fps | 97.8% |
| IMR 8208 XBR | <<locked>> | 80% | 43,947 psi | 68% | 2493 fps | 99.5% |
| Lovex D073.5 | <<locked>> | 80% | 49,516 psi | 76% | 2572 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 40,712 psi | 63% | 2464 fps | 99.9% |
| Lovex S060 | <<locked>> | 80% | 42,308 psi | 65% | 2428 fps | 98.5% |
| Lovex S062 | <<locked>> | 80% | 37,333 psi | 57% | 2379 fps | 98.6% |
| Lovex S065 | <<locked>> | 88% | 39,146 psi | 60% | 2415 fps | 95% |
| Lovex S070 | <<locked>> | 94% | 44,527 psi | 69% | 2536 fps | 95.3% |
| Norma 201 | <<locked>> | 80% | 40,988 psi | 63% | 2438 fps | 99.2% |
| Norma 202 | <<locked>> | 80% | 41,220 psi | 63% | 2448 fps | 100% |
| Norma 203B | <<locked>> | 80% | 37,130 psi | 57% | 2408 fps | 97.4% |
| Norma URP | <<locked>> | 88% | 34,809 psi | 54% | 2402 fps | 95% |
| Ramshot Big Game | <<locked>> | 80% | 36,463 psi | 56% | 2418 fps | 96.9% |
| Ramshot Hunter | <<locked>> | 94% | 41,466 psi | 64% | 2543 fps | 95.1% |
| Ramshot TAC | <<locked>> | 80% | 43,830 psi | 67% | 2493 fps | 96.5% |
| Ramshot Wild Boar | <<locked>> | 80% | 43,163 psi | 66% | 2513 fps | 98.6% |
| Ramshot X-Terminator | <<locked>> | 80% | 47,369 psi | 73% | 2536 fps | 99.1% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,411 psi | 41% | 1473 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 49,197 psi | 76% | 2572 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 86% | 43,758 psi | 67% | 2503 fps | 95.5% |
| ReloadSwiss RS 52 | 54.2 gr | 80% | 39,189 psi | 60% | 2510 fps | 97.4% |
| ReloadSwiss RS 60 | 55.1 gr | 80% | 32,256 psi | 50% | 2385 fps | 98.5% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 36,593 psi | 56% | 2467 fps | 95.4% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 39,610 psi | 61% | 2530 fps | 95.4% |
| Rottweil R 901 | <<locked>> | 80% | 45,092 psi | 69% | 2484 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 39,117 psi | 60% | 2395 fps | 98.9% |
| Rottweil R 903 | <<locked>> | 80% | 32,430 psi | 50% | 2310 fps | 96.6% |
| Rottweil R 907 | <<locked>> | 94% | 48,762 psi | 75% | 2579 fps | 95.4% |
| Shooters World Long Rifle | <<locked>> | 88% | 39,146 psi | 60% | 2415 fps | 95% |
| Shooters World Match Rifle | <<locked>> | 80% | 40,712 psi | 63% | 2464 fps | 99.9% |
| Shooters World Precision | <<locked>> | 80% | 37,333 psi | 57% | 2379 fps | 98.6% |
| Shooters World SW4350 | <<locked>> | 94% | 44,527 psi | 69% | 2536 fps | 95.3% |
| Shooters World Tactical Rifle | <<locked>> | 80% | 52,011 psi | 80% | 2589 fps | 99.9% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 33,475 psi | 51% | 2352 fps | 96% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 52,054 psi | 80% | 2566 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 41,930 psi | 65% | 2467 fps | 96.6% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 40,422 psi | 62% | 2454 fps | 98.1% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 42,511 psi | 65% | 2398 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 35,186 psi | 54% | 2274 fps | 99.9% |
| SNPE Vectan Tubal 7000 | <<locked>> | 94% | 46,818 psi | 72% | 2510 fps | 95.6% |
| Somchem S321 | <<locked>> | 80% | 47,384 psi | 73% | 2569 fps | 99.9% |
| Somchem S335 | <<locked>> | 80% | 42,047 psi | 65% | 2402 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 41,713 psi | 64% | 2467 fps | 98.3% |
| Somchem S355 | <<locked>> | 80% | 33,373 psi | 51% | 2316 fps | 96.7% |
| Somchem S365 | <<locked>> | 84% | 27,441 psi | 42% | 2247 fps | 95.4% |
| Vihtavuori N130 | <<locked>> | 80% | 48,080 psi | 74% | 2461 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 42,757 psi | 66% | 2395 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 38,305 psi | 59% | 2382 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 38,986 psi | 60% | 2388 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 31,734 psi | 49% | 2260 fps | 97.6% |
| Vihtavuori N160 | <<locked>> | 88% | 36,434 psi | 56% | 2402 fps | 95.5% |
| Vihtavuori N530 | <<locked>> | 80% | 44,048 psi | 68% | 2490 fps | 99.6% |
| Vihtavuori N540 | <<locked>> | 80% | 37,521 psi | 58% | 2379 fps | 99.8% |
| Vihtavuori N550 | <<locked>> | 88% | 35,824 psi | 55% | 2408 fps | 95.1% |
| Vihtavuori N555 | <<locked>> | 96% | 33,794 psi | 52% | 2434 fps | 95.6% |
| Winchester 6.5 StaBALL | <<locked>> | 82% | 30,240 psi | 47% | 2234 fps | 95.2% |
| Winchester 748 | <<locked>> | 80% | 43,178 psi | 66% | 2530 fps | 99.8% |
| Winchester 760 | <<locked>> | 94% | 45,252 psi | 70% | 2608 fps | 95.3% |
| Winchester StaBALL Match | <<locked>> | 80% | 39,624 psi | 61% | 2454 fps | 98.5% |
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 106 powders for .338 Weatherby RPM loaded with the .338 | 215gr | Sierra GameKing. Alliant Reloder-17 delivers the highest muzzle velocity at 2,864 fps; across all powders the maximum-charge window runs from 1,614 fps to 2,864 fps. Accurate 4350 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 54–90 %, leaving at least 10 % headroom. The 215.0 gr projectile in 0.338" calls for a 1:15.5 twist; slower twists will usually not stabilise this weight. Accurate 4350, Alliant Reloder-16, Alliant Reloder-17 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, ReloadSwiss RS 60, ReloadSwiss RS 52 rank at the top here: for .338 Weatherby RPM with the .338 | 215gr | Sierra GameKing 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.