Load Specifications
Bullet:.338 | 225gr | Hornady GMX
Bullet Manufacturer:Hornady
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:1:12.0
Load data in caliber .338 Weatherby RPM with .338 | 225gr | Hornady GMX bullet and 107 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 CFE223 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>> | 90% | 57,624 psi | 89% | 2533 fps | 100% |
| Accurate 2200 | <<locked>> | 82% | 57,986 psi | 89% | 2635 fps | 99.7% |
| Accurate 2460 | <<locked>> | 86% | 56,072 psi | 86% | 2562 fps | 100% |
| Accurate 2495 | <<locked>> | 96% | 58,131 psi | 89% | 2589 fps | 100% |
| Accurate 2520 | <<locked>> | 90% | 57,754 psi | 89% | 2618 fps | 100% |
| Accurate 2700 | <<locked>> | 94% | 55,651 psi | 86% | 2549 fps | 96.3% |
| Accurate 4064 | <<locked>> | 98% | 57,841 psi | 89% | 2631 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 46,673 psi | 72% | 2556 fps | 98.3% |
| Accurate LT-30 | <<locked>> | 84% | 57,217 psi | 88% | 2480 fps | 100% |
| Accurate LT-32 | <<locked>> | 84% | 57,667 psi | 89% | 2507 fps | 100% |
| ADI AR 2206H | <<locked>> | 92% | 56,594 psi | 87% | 2628 fps | 99.9% |
| ADI AR 2208 | <<locked>> | 98% | 57,653 psi | 89% | 2625 fps | 99.7% |
| ADI AR 2219 | <<locked>> | 84% | 58,233 psi | 90% | 2598 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 90% | 55,898 psi | 86% | 2585 fps | 100% |
| Alliant AR-Comp | <<locked>> | 90% | 55,796 psi | 86% | 2559 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 86% | 57,696 psi | 89% | 2684 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 94% | 56,014 psi | 86% | 2733 fps | 99.7% |
| Alliant Reloder- TS 15.5 | <<locked>> | 98% | 56,724 psi | 87% | 2641 fps | 100% |
| Alliant Reloder-10x | <<locked>> | 86% | 57,392 psi | 88% | 2539 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 96% | 57,798 psi | 89% | 2664 fps | 99.8% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 46,485 psi | 72% | 2562 fps | 98.4% |
| Alliant Reloder-17ᴾ | <<locked>> | 100% | 53,896 psi | 83% | 2703 fps | 100% |
| Baschieri & Pellagri 106 | <<locked>> | 84% | 56,405 psi | 87% | 2484 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 92% | 56,565 psi | 87% | 2644 fps | 99.5% |
| Bofors RP3 | <<locked>> | 98% | 57,203 psi | 88% | 2654 fps | 100% |
| Bofors RP7ᴾ | <<locked>> | 100% | 54,578 psi | 84% | 2575 fps | 96.4% |
| Hodgdon Benchmark | <<locked>> | 90% | 58,102 psi | 89% | 2569 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 92% | 58,566 psi | 90% | 2661 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 88% | 56,666 psi | 87% | 2703 fps | 99.8% |
| Hodgdon H322 | <<locked>> | 86% | 56,652 psi | 87% | 2579 fps | 100% |
| Hodgdon H335 | <<locked>> | 86% | 57,870 psi | 89% | 2608 fps | 100% |
| Hodgdon H380 | <<locked>> | 98% | 58,813 psi | 90% | 2667 fps | 99.3% |
| Hodgdon H414ᴾ | <<locked>> | 100% | 50,328 psi | 77% | 2605 fps | 96.4% |
| Hodgdon H4350ᴾ | <<locked>> | 100% | 55,332 psi | 85% | 2625 fps | 95.9% |
| Hodgdon H4895 | <<locked>> | 92% | 57,130 psi | 88% | 2638 fps | 100% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 42,496 psi | 65% | 2454 fps | 98.8% |
| Hodgdon LEVERevolution | <<locked>> | 94% | 55,970 psi | 86% | 2667 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 34,563 psi | 53% | 1532 fps | 100% |
| Hodgdon VARGET | <<locked>> | 94% | 58,726 psi | 90% | 2638 fps | 100% |
| IMR 3031 | <<locked>> | 92% | 56,376 psi | 87% | 2618 fps | 100% |
| IMR 4064 | <<locked>> | 96% | 57,043 psi | 88% | 2608 fps | 99.8% |
| IMR 4166 Enduron | <<locked>> | 94% | 57,740 psi | 89% | 2592 fps | 97.5% |
| IMR 4198 | <<locked>> | 86% | 57,899 psi | 89% | 2500 fps | 100% |
| IMR 4451 Enduronᴾ | <<locked>> | 100% | 56,884 psi | 88% | 2608 fps | 97.3% |
| IMR 4831ᴾ | <<locked>> | 100% | 44,628 psi | 69% | 2503 fps | 98% |
| IMR 4895 | <<locked>> | 94% | 55,593 psi | 86% | 2644 fps | 99.9% |
| IMR 8208 XBR | <<locked>> | 90% | 55,898 psi | 86% | 2585 fps | 100% |
| Lovex D073.5 | <<locked>> | 86% | 55,811 psi | 86% | 2572 fps | 100% |
| Lovex D073.6 | <<locked>> | 92% | 55,796 psi | 86% | 2605 fps | 100% |
| Lovex S060 | <<locked>> | 92% | 56,768 psi | 87% | 2562 fps | 99.9% |
| Lovex S062 | <<locked>> | 96% | 56,217 psi | 86% | 2602 fps | 100% |
| Lovex S065ᴾ | <<locked>> | 100% | 51,982 psi | 80% | 2549 fps | 97.9% |
| Lovex S070ᴾ | <<locked>> | 100% | 49,168 psi | 76% | 2530 fps | 96.3% |
| Norma 200 | <<locked>> | 82% | 56,913 psi | 88% | 2507 fps | 100% |
| Norma 201 | <<locked>> | 94% | 58,711 psi | 90% | 2621 fps | 100% |
| Norma 202 | <<locked>> | 92% | 55,637 psi | 86% | 2579 fps | 100% |
| Norma 203B | <<locked>> | 96% | 56,884 psi | 88% | 2651 fps | 99.9% |
| Norma URPᴾ | <<locked>> | 100% | 46,630 psi | 72% | 2549 fps | 98.2% |
| Ramshot Big Game | <<locked>> | 96% | 57,493 psi | 88% | 2677 fps | 99.9% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 45,963 psi | 71% | 2539 fps | 96.2% |
| Ramshot TAC | <<locked>> | 90% | 56,492 psi | 87% | 2605 fps | 98.7% |
| Ramshot Wild Boar | <<locked>> | 90% | 55,709 psi | 86% | 2621 fps | 99.8% |
| Ramshot X-Terminator | <<locked>> | 88% | 57,145 psi | 88% | 2589 fps | 99.8% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 34,882 psi | 54% | 1568 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 86% | 55,622 psi | 86% | 2569 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 96% | 55,883 psi | 86% | 2605 fps | 97.8% |
| ReloadSwiss RS 52 | <<locked>> | 94% | 58,102 psi | 89% | 2726 fps | 99.8% |
| ReloadSwiss RS 60ᴾ | <<locked>> | 100% | 57,638 psi | 89% | 2756 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 46,325 psi | 71% | 2572 fps | 98% |
| ReloadSwiss RS 70ᴾ | <<locked>> | 100% | 47,645 psi | 73% | 2598 fps | 97.5% |
| Rottweil R 901 | <<locked>> | 90% | 55,941 psi | 86% | 2556 fps | 100% |
| Rottweil R 902 | <<locked>> | 94% | 55,506 psi | 85% | 2572 fps | 100% |
| Rottweil R 903ᴾ | <<locked>> | 100% | 56,739 psi | 87% | 2641 fps | 100% |
| Rottweil R 907ᴾ | <<locked>> | 100% | 54,578 psi | 84% | 2575 fps | 96.4% |
| Shooters World Long Rifleᴾ | <<locked>> | 100% | 51,982 psi | 80% | 2549 fps | 97.9% |
| Shooters World Match Rifle | <<locked>> | 92% | 55,796 psi | 86% | 2605 fps | 100% |
| Shooters World Precision | <<locked>> | 96% | 56,217 psi | 86% | 2602 fps | 100% |
| Shooters World SW4350ᴾ | <<locked>> | 100% | 49,168 psi | 76% | 2530 fps | 96.3% |
| Shooters World Tactical Rifle | <<locked>> | 84% | 55,579 psi | 86% | 2546 fps | 100% |
| SNPE Vectan BA6 1/2 | <<locked>> | 82% | 57,334 psi | 88% | 2244 fps | 100% |
| SNPE Vectan SP 10 | <<locked>> | 84% | 58,421 psi | 90% | 2612 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 98% | 55,419 psi | 85% | 2657 fps | 99.8% |
| SNPE Vectan SP 3 | <<locked>> | 86% | 58,639 psi | 90% | 2559 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 92% | 58,276 psi | 90% | 2631 fps | 99.2% |
| SNPE Vectan SP 9 | <<locked>> | 94% | 58,581 psi | 90% | 2648 fps | 99.9% |
| SNPE Vectan Tubal 3000 | <<locked>> | 92% | 57,493 psi | 88% | 2523 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 98% | 57,116 psi | 88% | 2520 fps | 100% |
| SNPE Vectan Tubal 7000ᴾ | <<locked>> | 100% | 52,446 psi | 81% | 2507 fps | 96.6% |
| Somchem S321 | <<locked>> | 88% | 57,246 psi | 88% | 2618 fps | 100% |
| Somchem S335 | <<locked>> | 92% | 56,318 psi | 87% | 2520 fps | 100% |
| Somchem S341 | <<locked>> | 92% | 57,856 psi | 89% | 2625 fps | 99.9% |
| Somchem S355ᴾ | <<locked>> | 100% | 57,493 psi | 88% | 2644 fps | 100% |
| Somchem S365ᴾ | <<locked>> | 100% | 41,350 psi | 64% | 2500 fps | 99.6% |
| Vihtavuori N120 | <<locked>> | 82% | 58,798 psi | 90% | 2444 fps | 100% |
| Vihtavuori N130 | <<locked>> | 88% | 57,145 psi | 88% | 2490 fps | 100% |
| Vihtavuori N133 | <<locked>> | 92% | 57,435 psi | 88% | 2507 fps | 100% |
| Vihtavuori N135 | <<locked>> | 96% | 58,407 psi | 90% | 2582 fps | 100% |
| Vihtavuori N140 | <<locked>> | 94% | 56,260 psi | 87% | 2559 fps | 100% |
| Vihtavuori N150ᴾ | <<locked>> | 100% | 55,564 psi | 85% | 2579 fps | 100% |
| Vihtavuori N160ᴾ | <<locked>> | 100% | 49,342 psi | 76% | 2552 fps | 98.5% |
| Vihtavuori N530 | <<locked>> | 90% | 56,608 psi | 87% | 2585 fps | 100% |
| Vihtavuori N540 | <<locked>> | 96% | 57,769 psi | 89% | 2602 fps | 100% |
| Vihtavuori N550ᴾ | <<locked>> | 100% | 48,240 psi | 74% | 2556 fps | 98.2% |
| Winchester 6.5 StaBALLᴾ | <<locked>> | 100% | 50,299 psi | 77% | 2539 fps | 99.8% |
| Winchester 748 | <<locked>> | 90% | 55,825 psi | 86% | 2628 fps | 100% |
| Winchester 760ᴾ | <<locked>> | 100% | 50,604 psi | 78% | 2608 fps | 96.5% |
| Winchester StaBALL Match | <<locked>> | 94% | 58,349 psi | 90% | 2657 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% | 41,959 psi | 65% | 2326 fps | 100% |
| Accurate 2200 | <<locked>> | 80% | 53,983 psi | 83% | 2579 fps | 99.4% |
| Accurate 2460 | <<locked>> | 80% | 45,643 psi | 70% | 2421 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 34,142 psi | 53% | 2244 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 40,857 psi | 63% | 2379 fps | 99.9% |
| Accurate 2700 | <<locked>> | 92% | 52,243 psi | 80% | 2500 fps | 95.6% |
| Accurate 4064 | <<locked>> | 80% | 32,329 psi | 50% | 2231 fps | 99.4% |
| Accurate 4350 | <<locked>> | 92% | 35,070 psi | 54% | 2346 fps | 95.3% |
| Accurate LT-30 | <<locked>> | 80% | 50,604 psi | 78% | 2398 fps | 100% |
| Accurate LT-32 | <<locked>> | 80% | 51,024 psi | 78% | 2421 fps | 100% |
| ADI AR 2206H | <<locked>> | 80% | 38,609 psi | 59% | 2339 fps | 97.6% |
| ADI AR 2208 | <<locked>> | 80% | 32,895 psi | 51% | 2201 fps | 95% |
| ADI AR 2219 | <<locked>> | 80% | 51,024 psi | 78% | 2510 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 80% | 40,698 psi | 63% | 2352 fps | 99% |
| Alliant AR-Comp | <<locked>> | 80% | 40,045 psi | 62% | 2352 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 80% | 47,253 psi | 73% | 2533 fps | 99.5% |
| Alliant Power Pro 2000-MR | 50.9 gr | 80% | 34,737 psi | 53% | 2343 fps | 95.1% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 31,850 psi | 49% | 2218 fps | 96.6% |
| Alliant Reloder-10x | <<locked>> | 80% | 47,703 psi | 73% | 2415 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 34,476 psi | 53% | 2274 fps | 95.9% |
| Alliant Reloder-16 | <<locked>> | 92% | 36,448 psi | 56% | 2365 fps | 95.6% |
| Alliant Reloder-17 | <<locked>> | 84% | 31,517 psi | 48% | 2280 fps | 95.5% |
| Baschieri & Pellagri 106 | <<locked>> | 80% | 49,777 psi | 77% | 2402 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 37,666 psi | 58% | 2339 fps | 96.2% |
| Bofors RP3 | <<locked>> | 80% | 30,966 psi | 48% | 2211 fps | 96.4% |
| Bofors RP7 | <<locked>> | 96% | 47,979 psi | 74% | 2477 fps | 95% |
| Hodgdon Benchmark | <<locked>> | 80% | 42,801 psi | 66% | 2349 fps | 99.6% |
| Hodgdon BL-C2 | <<locked>> | 80% | 38,725 psi | 60% | 2365 fps | 99.1% |
| Hodgdon CFE223 | 52.1 gr | 80% | 42,685 psi | 66% | 2487 fps | 98.1% |
| Hodgdon H322 | <<locked>> | 80% | 46,702 psi | 72% | 2448 fps | 100% |
| Hodgdon H335 | <<locked>> | 80% | 47,282 psi | 73% | 2467 fps | 100% |
| Hodgdon H380 | <<locked>> | 84% | 36,927 psi | 57% | 2320 fps | 95.2% |
| Hodgdon H414 | <<locked>> | 98% | 47,108 psi | 72% | 2552 fps | 95.6% |
| Hodgdon H4350 | <<locked>> | 98% | 51,924 psi | 80% | 2575 fps | 95.1% |
| Hodgdon H4895 | <<locked>> | 80% | 38,885 psi | 60% | 2349 fps | 98.2% |
| Hodgdon Hybrid 100V | <<locked>> | 90% | 30,937 psi | 48% | 2215 fps | 95.4% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 34,751 psi | 53% | 2316 fps | 97.6% |
| Hodgdon TrailBoss | <<locked>> | 80% | 25,657 psi | 39% | 1368 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 37,637 psi | 58% | 2310 fps | 97.8% |
| IMR 3031 | <<locked>> | 80% | 38,000 psi | 58% | 2352 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 34,461 psi | 53% | 2234 fps | 95.9% |
| IMR 4166 Enduron | <<locked>> | 88% | 47,848 psi | 74% | 2444 fps | 95.6% |
| IMR 4198 | <<locked>> | 80% | 48,573 psi | 75% | 2382 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 94% | 47,137 psi | 73% | 2464 fps | 95.3% |
| IMR 4831 | <<locked>> | 92% | 34,142 psi | 53% | 2306 fps | 95% |
| IMR 4895 | <<locked>> | 80% | 35,259 psi | 54% | 2300 fps | 96.8% |
| IMR 8208 XBR | <<locked>> | 80% | 40,698 psi | 63% | 2352 fps | 99% |
| Lovex D073.5 | <<locked>> | 80% | 45,426 psi | 70% | 2428 fps | 99.9% |
| Lovex D073.6 | <<locked>> | 80% | 36,970 psi | 57% | 2320 fps | 99.5% |
| Lovex S060 | <<locked>> | 80% | 39,349 psi | 61% | 2290 fps | 97.8% |
| Lovex S062 | <<locked>> | 80% | 34,055 psi | 52% | 2238 fps | 97.7% |
| Lovex S065 | <<locked>> | 92% | 40,524 psi | 62% | 2362 fps | 95.3% |
| Lovex S070 | <<locked>> | 98% | 46,093 psi | 71% | 2480 fps | 95.5% |
| Norma 200 | <<locked>> | 80% | 53,664 psi | 83% | 2467 fps | 100% |
| Norma 201 | <<locked>> | 80% | 37,768 psi | 58% | 2300 fps | 98.6% |
| Norma 202 | <<locked>> | 80% | 37,869 psi | 58% | 2310 fps | 99.8% |
| Norma 203B | <<locked>> | 80% | 33,852 psi | 52% | 2264 fps | 96.3% |
| Norma URP | <<locked>> | 92% | 36,027 psi | 55% | 2352 fps | 95.4% |
| Ramshot Big Game | <<locked>> | 80% | 33,286 psi | 51% | 2270 fps | 95.7% |
| Ramshot Hunter | <<locked>> | 98% | 43,134 psi | 66% | 2490 fps | 95.4% |
| Ramshot TAC | <<locked>> | 80% | 40,640 psi | 63% | 2352 fps | 95.5% |
| Ramshot Wild Boar | <<locked>> | 80% | 39,726 psi | 61% | 2369 fps | 97.8% |
| Ramshot X-Terminator | <<locked>> | 80% | 43,990 psi | 68% | 2395 fps | 98.5% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 25,831 psi | 40% | 1401 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 45,658 psi | 70% | 2428 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 88% | 42,946 psi | 66% | 2405 fps | 95.1% |
| ReloadSwiss RS 52 | 49.4 gr | 80% | 35,679 psi | 55% | 2359 fps | 96.2% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 29,457 psi | 45% | 2234 fps | 97.3% |
| ReloadSwiss RS 62 | <<locked>> | 94% | 37,782 psi | 58% | 2418 fps | 95.7% |
| ReloadSwiss RS 70 | <<locked>> | 96% | 41,452 psi | 64% | 2484 fps | 95.8% |
| Rottweil R 901 | <<locked>> | 80% | 41,321 psi | 64% | 2339 fps | 99.9% |
| Rottweil R 902 | <<locked>> | 80% | 35,853 psi | 55% | 2254 fps | 98.1% |
| Rottweil R 903 | <<locked>> | 80% | 29,182 psi | 45% | 2162 fps | 95.3% |
| Rottweil R 907 | <<locked>> | 96% | 47,979 psi | 74% | 2477 fps | 95% |
| Shooters World Long Rifle | <<locked>> | 92% | 40,524 psi | 62% | 2362 fps | 95.3% |
| Shooters World Match Rifle | <<locked>> | 80% | 36,970 psi | 57% | 2320 fps | 99.5% |
| Shooters World Precision | <<locked>> | 80% | 34,055 psi | 52% | 2238 fps | 97.7% |
| Shooters World SW4350 | <<locked>> | 98% | 46,093 psi | 71% | 2480 fps | 95.5% |
| Shooters World Tactical Rifle | <<locked>> | 80% | 48,312 psi | 74% | 2444 fps | 99.7% |
| SNPE Vectan BA6 1/2 | <<locked>> | 80% | 54,375 psi | 84% | 2211 fps | 100% |
| SNPE Vectan SP 10 | <<locked>> | 80% | 51,271 psi | 79% | 2520 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 82% | 32,619 psi | 50% | 2260 fps | 95.6% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 48,573 psi | 75% | 2434 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 38,421 psi | 59% | 2320 fps | 95.5% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 37,275 psi | 57% | 2313 fps | 97.3% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 39,494 psi | 61% | 2267 fps | 99.9% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 32,416 psi | 50% | 2146 fps | 99.6% |
| SNPE Vectan Tubal 7000 | <<locked>> | 96% | 45,774 psi | 70% | 2411 fps | 95.1% |
| Somchem S321 | <<locked>> | 80% | 43,758 psi | 67% | 2425 fps | 99.6% |
| Somchem S335 | <<locked>> | 80% | 38,986 psi | 60% | 2270 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 38,348 psi | 59% | 2326 fps | 97.5% |
| Somchem S355 | <<locked>> | 80% | 30,429 psi | 47% | 2175 fps | 95.5% |
| Somchem S365 | <<locked>> | 88% | 28,094 psi | 43% | 2198 fps | 95.7% |
| Vihtavuori N120 | <<locked>> | 80% | 55,434 psi | 85% | 2405 fps | 100% |
| Vihtavuori N130 | <<locked>> | 80% | 44,889 psi | 69% | 2333 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 39,711 psi | 61% | 2267 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 34,896 psi | 54% | 2247 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 35,882 psi | 55% | 2254 fps | 99.8% |
| Vihtavuori N150 | <<locked>> | 80% | 28,805 psi | 44% | 2123 fps | 96.5% |
| Vihtavuori N160 | <<locked>> | 90% | 35,505 psi | 55% | 2306 fps | 95% |
| Vihtavuori N530 | <<locked>> | 80% | 40,538 psi | 62% | 2346 fps | 99.1% |
| Vihtavuori N540 | <<locked>> | 80% | 34,476 psi | 53% | 2244 fps | 99.4% |
| Vihtavuori N550 | <<locked>> | 92% | 37,014 psi | 57% | 2356 fps | 95.4% |
| Winchester 6.5 StaBALL | <<locked>> | 86% | 31,517 psi | 48% | 2192 fps | 95.7% |
| Winchester 748 | <<locked>> | 80% | 39,537 psi | 61% | 2385 fps | 99.4% |
| Winchester 760 | <<locked>> | 98% | 47,384 psi | 73% | 2556 fps | 95.7% |
| Winchester StaBALL Match | <<locked>> | 80% | 36,332 psi | 56% | 2313 fps | 97.6% |
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 | Hornady GMX. ReloadSwiss RS 60 delivers the highest muzzle velocity at 2,756 fps; across all powders the maximum-charge window runs from 1,532 fps to 2,756 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 53–90 %, leaving at least 10 % headroom. The 225.0 gr projectile in 0.338" calls for a 1:12.0 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, Hodgdon CFE223, ReloadSwiss RS 52 rank at the top here: for .338 Weatherby RPM with the .338 | 225gr | Hornady GMX 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.