Load Specifications
Bullet:.338 | 225gr | Speer TBBC
Bullet Manufacturer:Speer
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 | Speer TBBC 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>> | 88% | 58,581 psi | 90% | 2562 fps | 100% |
| Accurate 2460 | <<locked>> | 84% | 57,203 psi | 88% | 2592 fps | 100% |
| Accurate 2495 | <<locked>> | 92% | 57,029 psi | 88% | 2589 fps | 100% |
| Accurate 2520 | <<locked>> | 86% | 55,477 psi | 85% | 2608 fps | 100% |
| Accurate 2700 | <<locked>> | 92% | 56,724 psi | 87% | 2589 fps | 97% |
| Accurate 4064 | <<locked>> | 94% | 56,623 psi | 87% | 2628 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 52,257 psi | 80% | 2654 fps | 99.3% |
| Accurate LT-30 | <<locked>> | 82% | 57,421 psi | 88% | 2507 fps | 100% |
| Accurate LT-32 | <<locked>> | 82% | 57,856 psi | 89% | 2533 fps | 100% |
| ADI AR 2206H | <<locked>> | 90% | 57,754 psi | 89% | 2664 fps | 100% |
| ADI AR 2208 | <<locked>> | 96% | 58,581 psi | 90% | 2661 fps | 99.9% |
| ADI Benchmark 8208 | <<locked>> | 88% | 56,811 psi | 87% | 2618 fps | 100% |
| Alliant AR-Comp | <<locked>> | 88% | 57,537 psi | 89% | 2592 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 84% | 58,755 psi | 90% | 2717 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 92% | 57,435 psi | 88% | 2779 fps | 99.9% |
| Alliant Reloder- TS 15.5 | <<locked>> | 96% | 58,334 psi | 90% | 2680 fps | 100% |
| Alliant Reloder-10x | <<locked>> | 84% | 58,320 psi | 90% | 2566 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 92% | 55,463 psi | 85% | 2654 fps | 99.8% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 50,923 psi | 78% | 2661 fps | 99.4% |
| Alliant Reloder-17 | <<locked>> | 98% | 55,317 psi | 85% | 2746 fps | 100% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 36,071 psi | 55% | 2411 fps | 97.7% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 39,900 psi | 61% | 2546 fps | 96.6% |
| Baschieri & Pellagri 106 | <<locked>> | 82% | 56,637 psi | 87% | 2507 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 90% | 57,479 psi | 88% | 2680 fps | 99.8% |
| Bofors RP3 | <<locked>> | 94% | 55,448 psi | 85% | 2651 fps | 100% |
| Bofors RP7 | <<locked>> | 98% | 55,709 psi | 86% | 2618 fps | 97.1% |
| Hodgdon Benchmark | <<locked>> | 88% | 58,624 psi | 90% | 2598 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 88% | 55,869 psi | 86% | 2648 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 86% | 58,247 psi | 90% | 2743 fps | 100% |
| Hodgdon H322 | <<locked>> | 84% | 57,653 psi | 89% | 2612 fps | 100% |
| Hodgdon H335 | <<locked>> | 84% | 58,726 psi | 90% | 2638 fps | 100% |
| Hodgdon H380 | <<locked>> | 94% | 56,550 psi | 87% | 2661 fps | 99.4% |
| Hodgdon H414ᴾ | <<locked>> | 100% | 55,564 psi | 85% | 2703 fps | 97.9% |
| Hodgdon H4350 | <<locked>> | 98% | 56,550 psi | 87% | 2667 fps | 96.6% |
| Hodgdon H4895 | <<locked>> | 90% | 58,378 psi | 90% | 2674 fps | 100% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 47,137 psi | 73% | 2549 fps | 99.7% |
| Hodgdon LEVERevolution | <<locked>> | 92% | 57,261 psi | 88% | 2703 fps | 100% |
| Hodgdon Superformanceᴾ | <<locked>> | 100% | 56,898 psi | 88% | 2743 fps | 97.5% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,302 psi | 54% | 1568 fps | 100% |
| Hodgdon VARGET | <<locked>> | 90% | 56,086 psi | 86% | 2628 fps | 100% |
| IMR 3031 | <<locked>> | 90% | 57,986 psi | 89% | 2651 fps | 100% |
| IMR 4064 | <<locked>> | 94% | 57,986 psi | 89% | 2641 fps | 99.9% |
| IMR 4166 Enduron | <<locked>> | 92% | 58,450 psi | 90% | 2628 fps | 98.1% |
| IMR 4198 | <<locked>> | 84% | 58,349 psi | 90% | 2523 fps | 100% |
| IMR 4350ᴾ | <<locked>> | 100% | 52,272 psi | 80% | 2592 fps | 96.5% |
| IMR 4451 Enduron | <<locked>> | 98% | 57,682 psi | 89% | 2648 fps | 97.9% |
| IMR 4831ᴾ | <<locked>> | 100% | 49,632 psi | 76% | 2602 fps | 99.1% |
| IMR 4895 | <<locked>> | 92% | 56,855 psi | 87% | 2680 fps | 100% |
| IMR 8208 XBR | <<locked>> | 88% | 56,811 psi | 87% | 2618 fps | 100% |
| Lovex D073.5 | <<locked>> | 84% | 57,043 psi | 88% | 2605 fps | 100% |
| Lovex D073.6 | <<locked>> | 90% | 57,305 psi | 88% | 2641 fps | 100% |
| Lovex S060 | <<locked>> | 90% | 57,435 psi | 88% | 2595 fps | 100% |
| Lovex S062 | <<locked>> | 94% | 57,769 psi | 89% | 2638 fps | 100% |
| Lovex S065ᴾ | <<locked>> | 100% | 56,579 psi | 87% | 2638 fps | 98.9% |
| Lovex S070ᴾ | <<locked>> | 100% | 53,998 psi | 83% | 2625 fps | 97.7% |
| Norma 201 | <<locked>> | 90% | 56,362 psi | 87% | 2612 fps | 100% |
| Norma 202 | <<locked>> | 90% | 56,826 psi | 87% | 2612 fps | 100% |
| Norma 203B | <<locked>> | 94% | 58,204 psi | 90% | 2690 fps | 100% |
| Norma URPᴾ | <<locked>> | 100% | 51,532 psi | 79% | 2644 fps | 99.2% |
| Ramshot Big Game | <<locked>> | 92% | 55,259 psi | 85% | 2671 fps | 99.9% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 50,589 psi | 78% | 2638 fps | 97.8% |
| Ramshot TAC | <<locked>> | 88% | 57,276 psi | 88% | 2638 fps | 99.1% |
| Ramshot Wild Boar | <<locked>> | 88% | 56,594 psi | 87% | 2654 fps | 100% |
| Ramshot X-Terminator | <<locked>> | 86% | 57,943 psi | 89% | 2621 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 35,679 psi | 55% | 1604 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 84% | 56,449 psi | 87% | 2602 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 94% | 56,956 psi | 88% | 2644 fps | 98.4% |
| ReloadSwiss RS 52 | <<locked>> | 90% | 55,811 psi | 86% | 2717 fps | 99.9% |
| ReloadSwiss RS 60 | <<locked>> | 96% | 55,274 psi | 85% | 2749 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 51,938 psi | 80% | 2677 fps | 99.1% |
| ReloadSwiss RS 70ᴾ | <<locked>> | 100% | 52,243 psi | 80% | 2700 fps | 98.9% |
| Rottweil R 901 | <<locked>> | 88% | 57,464 psi | 88% | 2592 fps | 100% |
| Rottweil R 902 | <<locked>> | 92% | 56,724 psi | 87% | 2605 fps | 100% |
| Rottweil R 903 | <<locked>> | 98% | 58,813 psi | 90% | 2687 fps | 100% |
| Rottweil R 907 | <<locked>> | 98% | 55,709 psi | 86% | 2618 fps | 97.1% |
| Shooters World Long Rifleᴾ | <<locked>> | 100% | 56,579 psi | 87% | 2638 fps | 98.9% |
| Shooters World Match Rifle | <<locked>> | 90% | 57,305 psi | 88% | 2641 fps | 100% |
| Shooters World Precision | <<locked>> | 94% | 57,769 psi | 89% | 2638 fps | 100% |
| Shooters World SW4350ᴾ | <<locked>> | 100% | 53,998 psi | 83% | 2625 fps | 97.7% |
| Shooters World Tactical Rifle | <<locked>> | 82% | 56,159 psi | 86% | 2575 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 96% | 57,014 psi | 88% | 2700 fps | 100% |
| SNPE Vectan SP 3 | <<locked>> | 82% | 55,811 psi | 86% | 2543 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 88% | 55,593 psi | 86% | 2618 fps | 99.2% |
| SNPE Vectan SP 9 | <<locked>> | 90% | 55,941 psi | 86% | 2635 fps | 99.9% |
| SNPE Vectan Tubal 3000 | <<locked>> | 90% | 58,131 psi | 89% | 2552 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 96% | 58,262 psi | 90% | 2549 fps | 100% |
| SNPE Vectan Tubal 7000ᴾ | <<locked>> | 100% | 57,537 psi | 89% | 2598 fps | 97.9% |
| Somchem S321 | <<locked>> | 86% | 58,291 psi | 90% | 2651 fps | 100% |
| Somchem S335 | <<locked>> | 90% | 57,319 psi | 88% | 2549 fps | 100% |
| Somchem S341 | <<locked>> | 90% | 58,726 psi | 90% | 2657 fps | 100% |
| Somchem S355 | <<locked>> | 96% | 55,332 psi | 85% | 2635 fps | 100% |
| Somchem S365ᴾ | <<locked>> | 100% | 46,195 psi | 71% | 2602 fps | 100% |
| Vihtavuori N130 | <<locked>> | 86% | 57,928 psi | 89% | 2516 fps | 100% |
| Vihtavuori N133 | <<locked>> | 90% | 58,204 psi | 90% | 2536 fps | 100% |
| Vihtavuori N135 | <<locked>> | 92% | 56,159 psi | 86% | 2572 fps | 100% |
| Vihtavuori N140 | <<locked>> | 92% | 57,392 psi | 88% | 2592 fps | 100% |
| Vihtavuori N150 | <<locked>> | 98% | 57,130 psi | 88% | 2618 fps | 100% |
| Vihtavuori N160ᴾ | <<locked>> | 100% | 54,259 psi | 83% | 2641 fps | 99.4% |
| Vihtavuori N530 | <<locked>> | 88% | 57,450 psi | 88% | 2618 fps | 100% |
| Vihtavuori N540 | <<locked>> | 92% | 55,434 psi | 85% | 2592 fps | 100% |
| Vihtavuori N550ᴾ | <<locked>> | 100% | 53,243 psi | 82% | 2648 fps | 99.2% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 38,899 psi | 60% | 2484 fps | 97.7% |
| Winchester 6.5 StaBALLᴾ | <<locked>> | 100% | 55,100 psi | 85% | 2628 fps | 100% |
| Winchester 748 | <<locked>> | 88% | 57,087 psi | 88% | 2664 fps | 100% |
| Winchester 760ᴾ | <<locked>> | 100% | 55,811 psi | 86% | 2707 fps | 97.9% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 32,198 psi | 50% | 2392 fps | 96.9% |
| Winchester StaBALL Match | <<locked>> | 90% | 55,912 psi | 86% | 2648 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% | 46,064 psi | 71% | 2402 fps | 100% |
| Accurate 2460 | <<locked>> | 80% | 50,053 psi | 77% | 2500 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 38,624 psi | 59% | 2329 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 45,295 psi | 70% | 2467 fps | 100% |
| Accurate 2700 | <<locked>> | 88% | 49,719 psi | 76% | 2490 fps | 95.6% |
| Accurate 4064 | <<locked>> | 80% | 36,521 psi | 56% | 2323 fps | 99.9% |
| Accurate 4350 | <<locked>> | 88% | 34,664 psi | 53% | 2349 fps | 95.6% |
| Accurate LT-30 | <<locked>> | 80% | 54,114 psi | 83% | 2467 fps | 100% |
| Accurate LT-32 | <<locked>> | 80% | 54,534 psi | 84% | 2490 fps | 100% |
| ADI AR 2206H | <<locked>> | 80% | 42,293 psi | 65% | 2425 fps | 98.7% |
| ADI AR 2208 | <<locked>> | 80% | 35,984 psi | 55% | 2287 fps | 96.6% |
| ADI Benchmark 8208 | <<locked>> | 80% | 44,309 psi | 68% | 2431 fps | 99.7% |
| Alliant AR-Comp | <<locked>> | 80% | 44,121 psi | 68% | 2421 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 80% | 51,692 psi | 80% | 2618 fps | 99.9% |
| Alliant Power Pro 2000-MR | 54.3 gr | 80% | 38,145 psi | 59% | 2441 fps | 97% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 35,476 psi | 55% | 2310 fps | 98.1% |
| Alliant Reloder-10x | <<locked>> | 80% | 51,721 psi | 80% | 2484 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 38,101 psi | 59% | 2362 fps | 97.4% |
| Alliant Reloder-16 | <<locked>> | 88% | 35,244 psi | 54% | 2359 fps | 95.7% |
| Alliant Reloder-17 | <<locked>> | 80% | 30,501 psi | 47% | 2267 fps | 95.6% |
| Alliant Reloder-23 | <<locked>> | 94% | 30,153 psi | 46% | 2264 fps | 95.2% |
| Alliant Reloder-26 | <<locked>> | 98% | 37,159 psi | 57% | 2484 fps | 95.5% |
| Baschieri & Pellagri 106 | <<locked>> | 80% | 53,359 psi | 82% | 2467 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 41,307 psi | 64% | 2428 fps | 97.6% |
| Bofors RP3 | <<locked>> | 80% | 34,751 psi | 53% | 2306 fps | 98% |
| Bofors RP7 | <<locked>> | 92% | 46,195 psi | 71% | 2470 fps | 95.1% |
| Hodgdon Benchmark | <<locked>> | 80% | 46,151 psi | 71% | 2425 fps | 99.9% |
| Hodgdon BL-C2 | <<locked>> | 80% | 42,743 psi | 66% | 2451 fps | 99.8% |
| Hodgdon CFE223 | <<locked>> | 80% | 47,108 psi | 72% | 2582 fps | 99.2% |
| Hodgdon H322 | <<locked>> | 80% | 50,517 psi | 78% | 2520 fps | 100% |
| Hodgdon H335 | <<locked>> | 80% | 51,517 psi | 79% | 2546 fps | 100% |
| Hodgdon H380 | <<locked>> | 80% | 35,781 psi | 55% | 2310 fps | 95.3% |
| Hodgdon H414 | <<locked>> | 92% | 42,830 psi | 66% | 2497 fps | 95% |
| Hodgdon H4350 | <<locked>> | 94% | 50,024 psi | 77% | 2569 fps | 95.3% |
| Hodgdon H4895 | <<locked>> | 80% | 42,656 psi | 66% | 2434 fps | 99.2% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 30,298 psi | 47% | 2215 fps | 95.7% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 38,537 psi | 59% | 2408 fps | 98.8% |
| Hodgdon Superformance | <<locked>> | 94% | 45,818 psi | 70% | 2566 fps | 95% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,266 psi | 40% | 1398 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 40,901 psi | 63% | 2388 fps | 98.8% |
| IMR 3031 | <<locked>> | 80% | 42,134 psi | 65% | 2434 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 37,753 psi | 58% | 2316 fps | 97.4% |
| IMR 4166 Enduron | <<locked>> | 84% | 45,730 psi | 70% | 2434 fps | 95.6% |
| IMR 4198 | <<locked>> | 80% | 51,953 psi | 80% | 2444 fps | 100% |
| IMR 4350 | <<locked>> | 96% | 46,079 psi | 71% | 2493 fps | 95.1% |
| IMR 4451 Enduron | <<locked>> | 90% | 45,353 psi | 70% | 2457 fps | 95.4% |
| IMR 4831 | <<locked>> | 88% | 33,605 psi | 52% | 2306 fps | 95.3% |
| IMR 4895 | <<locked>> | 80% | 38,972 psi | 60% | 2392 fps | 98.2% |
| IMR 8208 XBR | <<locked>> | 80% | 44,309 psi | 68% | 2431 fps | 99.7% |
| Lovex D073.5 | <<locked>> | 80% | 49,966 psi | 77% | 2510 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 41,002 psi | 63% | 2405 fps | 99.9% |
| Lovex S060 | <<locked>> | 80% | 42,554 psi | 65% | 2369 fps | 98.8% |
| Lovex S062 | <<locked>> | 80% | 37,608 psi | 58% | 2323 fps | 98.9% |
| Lovex S065 | <<locked>> | 88% | 39,523 psi | 61% | 2362 fps | 95.5% |
| Lovex S070 | <<locked>> | 92% | 42,221 psi | 65% | 2431 fps | 95% |
| Norma 201 | <<locked>> | 80% | 41,481 psi | 64% | 2382 fps | 99.4% |
| Norma 202 | <<locked>> | 80% | 41,713 psi | 64% | 2392 fps | 100% |
| Norma 203B | <<locked>> | 80% | 37,463 psi | 58% | 2352 fps | 97.8% |
| Norma URP | <<locked>> | 88% | 35,215 psi | 54% | 2349 fps | 95.6% |
| Ramshot Big Game | <<locked>> | 80% | 36,796 psi | 57% | 2362 fps | 97.4% |
| Ramshot Hunter | <<locked>> | 94% | 41,843 psi | 64% | 2487 fps | 95.6% |
| Ramshot TAC | <<locked>> | 80% | 44,164 psi | 68% | 2438 fps | 96.9% |
| Ramshot Wild Boar | <<locked>> | 80% | 43,540 psi | 67% | 2454 fps | 98.9% |
| Ramshot X-Terminator | <<locked>> | 80% | 47,718 psi | 73% | 2477 fps | 99.3% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,513 psi | 41% | 1430 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 49,690 psi | 76% | 2507 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 41,379 psi | 64% | 2395 fps | 95.2% |
| ReloadSwiss RS 52 | 52.6 gr | 80% | 39,508 psi | 61% | 2451 fps | 97.8% |
| ReloadSwiss RS 60 | 53.5 gr | 80% | 32,474 psi | 50% | 2333 fps | 98.8% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 34,563 psi | 53% | 2362 fps | 95% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 37,376 psi | 58% | 2421 fps | 95% |
| Rottweil R 901 | <<locked>> | 80% | 45,266 psi | 70% | 2418 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 39,537 psi | 61% | 2339 fps | 99.1% |
| Rottweil R 903 | <<locked>> | 80% | 32,764 psi | 50% | 2254 fps | 97.1% |
| Rottweil R 907 | <<locked>> | 92% | 46,195 psi | 71% | 2470 fps | 95.1% |
| Shooters World Long Rifle | <<locked>> | 88% | 39,523 psi | 61% | 2362 fps | 95.5% |
| Shooters World Match Rifle | <<locked>> | 80% | 41,002 psi | 63% | 2405 fps | 99.9% |
| Shooters World Precision | <<locked>> | 80% | 37,608 psi | 58% | 2323 fps | 98.9% |
| Shooters World SW4350 | <<locked>> | 92% | 42,221 psi | 65% | 2431 fps | 95% |
| Shooters World Tactical Rifle | <<locked>> | 80% | 52,388 psi | 81% | 2526 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 33,678 psi | 52% | 2300 fps | 96.5% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 52,504 psi | 81% | 2503 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 42,322 psi | 65% | 2411 fps | 97.1% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 40,640 psi | 63% | 2395 fps | 98.4% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 42,888 psi | 66% | 2339 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 35,534 psi | 55% | 2221 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 92% | 44,280 psi | 68% | 2405 fps | 95.3% |
| Somchem S321 | <<locked>> | 80% | 47,776 psi | 74% | 2507 fps | 100% |
| Somchem S335 | <<locked>> | 80% | 42,511 psi | 65% | 2346 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 42,119 psi | 65% | 2411 fps | 98.6% |
| Somchem S355 | <<locked>> | 80% | 33,808 psi | 52% | 2267 fps | 97.2% |
| Somchem S365 | <<locked>> | 82% | 26,049 psi | 40% | 2152 fps | 95.1% |
| Vihtavuori N130 | <<locked>> | 80% | 48,501 psi | 75% | 2398 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 43,134 psi | 66% | 2336 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 38,682 psi | 60% | 2323 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 39,334 psi | 61% | 2329 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 31,995 psi | 49% | 2205 fps | 98% |
| Vihtavuori N160 | <<locked>> | 86% | 34,534 psi | 53% | 2303 fps | 95.2% |
| Vihtavuori N530 | <<locked>> | 80% | 44,222 psi | 68% | 2428 fps | 99.7% |
| Vihtavuori N540 | <<locked>> | 80% | 37,913 psi | 58% | 2323 fps | 99.9% |
| Vihtavuori N550 | <<locked>> | 88% | 36,143 psi | 56% | 2352 fps | 95.6% |
| Vihtavuori N555 | <<locked>> | 94% | 32,039 psi | 49% | 2333 fps | 95.3% |
| Winchester 6.5 StaBALL | <<locked>> | 82% | 30,385 psi | 47% | 2182 fps | 95.8% |
| Winchester 748 | <<locked>> | 80% | 43,714 psi | 67% | 2470 fps | 99.9% |
| Winchester 760 | <<locked>> | 92% | 42,830 psi | 66% | 2497 fps | 95% |
| Winchester StaBALL HD | <<locked>> | 98% | 30,298 psi | 47% | 2333 fps | 95.6% |
| Winchester StaBALL Match | <<locked>> | 80% | 40,147 psi | 62% | 2402 fps | 98.8% |
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 107 powders for .338 Weatherby RPM loaded with the .338 | 225gr | Speer TBBC. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 2,779 fps; across all powders the maximum-charge window runs from 1,568 fps to 2,779 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 | Speer TBBC 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.