Load Specifications
Bullet Manufacturer:Speer
Bullet Weight:250 gr
Bullet Diameter:0.338"
Bullet Length:<<locked>>
Caliber:.338 Win Mag. load data
Case Length (l3):2.5"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:86 Grains of Water
Primer Size:Large Rifle (LR)
Barrel Length:24"
Max. allowed Pressure:62,366 psi
Recommended Twist Rate:1:6.0
Load data in caliber .338 Win Mag. with .338 | 250gr | Speer Grand Slam bullet and 104 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ReloadSwiss RS 70, Alliant Reloder-16 and Hodgdon Superformance.
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 2495 | <<locked>> | 84% | 53,867 psi | 86% | 2441 fps | 100% |
| Accurate 2700 | <<locked>> | 86% | 55,434 psi | 89% | 2503 fps | 98.7% |
| Accurate 3100ᴾ | <<locked>> | 100% | 47,776 psi | 77% | 2484 fps | 99% |
| Accurate 4064 | <<locked>> | 86% | 53,882 psi | 86% | 2487 fps | 100% |
| Accurate 4350 | <<locked>> | 94% | 53,983 psi | 87% | 2582 fps | 100% |
| Accurate High Countryᴾ | <<locked>> | 100% | 52,170 psi | 84% | 2661 fps | 97% |
| ADI AR 2206H | <<locked>> | 82% | 53,403 psi | 86% | 2510 fps | 100% |
| ADI AR 2208 | <<locked>> | 88% | 54,665 psi | 88% | 2520 fps | 100% |
| ADI AR 2209ᴾ | <<locked>> | 100% | 55,114 psi | 88% | 2618 fps | 98.1% |
| ADI Benchmark 8208 | <<locked>> | 82% | 55,608 psi | 89% | 2507 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 84% | 53,214 psi | 85% | 2625 fps | 100% |
| Alliant Power Pro Varmintᴾ | <<locked>> | 100% | 54,998 psi | 88% | 2615 fps | 98.2% |
| Alliant Reloder- TS 15.5 | <<locked>> | 88% | 55,085 psi | 88% | 2539 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 86% | 55,448 psi | 89% | 2559 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 96% | 54,795 psi | 88% | 2631 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 92% | 55,999 psi | 90% | 2657 fps | 100% |
| Alliant Reloder-19ᴾ | <<locked>> | 100% | 54,172 psi | 87% | 2608 fps | 98.1% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 47,819 psi | 77% | 2556 fps | 97.1% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 45,121 psi | 72% | 2507 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 39,479 psi | 63% | 2428 fps | 98.1% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 51,068 psi | 82% | 2674 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 82% | 53,055 psi | 85% | 2530 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 43,845 psi | 70% | 2484 fps | 95.9% |
| Bofors RP3 | <<locked>> | 88% | 55,608 psi | 89% | 2552 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 47,819 psi | 77% | 2556 fps | 97.1% |
| Bofors RP7 | <<locked>> | 92% | 55,347 psi | 89% | 2539 fps | 98.9% |
| Hodgdon BL-C2 | <<locked>> | 82% | 55,332 psi | 89% | 2539 fps | 100% |
| Hodgdon H380 | <<locked>> | 88% | 56,275 psi | 90% | 2569 fps | 100% |
| Hodgdon H414 | <<locked>> | 94% | 56,391 psi | 90% | 2631 fps | 99.4% |
| Hodgdon H4350 | <<locked>> | 90% | 53,301 psi | 85% | 2546 fps | 98.2% |
| Hodgdon H4895 | <<locked>> | 82% | 53,954 psi | 87% | 2520 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 98% | 55,071 psi | 88% | 2562 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 84% | 53,853 psi | 86% | 2556 fps | 100% |
| Hodgdon Superformance | <<locked>> | 92% | 52,678 psi | 84% | 2612 fps | 98.8% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,158 psi | 58% | 1539 fps | 100% |
| Hodgdon VARGET | <<locked>> | 84% | 55,187 psi | 88% | 2523 fps | 100% |
| IMR 3031 | <<locked>> | 82% | 54,549 psi | 87% | 2497 fps | 100% |
| IMR 4064 | <<locked>> | 86% | 54,128 psi | 87% | 2500 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 84% | 53,461 psi | 86% | 2484 fps | 99% |
| IMR 4350 | <<locked>> | 96% | 55,782 psi | 89% | 2566 fps | 99% |
| IMR 4451 Enduron | <<locked>> | 90% | 53,679 psi | 86% | 2516 fps | 99% |
| IMR 4831 | <<locked>> | 96% | 54,534 psi | 87% | 2575 fps | 100% |
| IMR 4895 | <<locked>> | 84% | 53,490 psi | 86% | 2539 fps | 100% |
| IMR 4955 Enduronᴾ | <<locked>> | 100% | 54,810 psi | 88% | 2552 fps | 96.4% |
| IMR 8208 XBR | <<locked>> | 82% | 55,608 psi | 89% | 2507 fps | 100% |
| Lovex D073.6 | <<locked>> | 82% | 53,548 psi | 86% | 2490 fps | 100% |
| Lovex S060 | <<locked>> | 84% | 56,101 psi | 90% | 2490 fps | 100% |
| Lovex S062 | <<locked>> | 86% | 54,099 psi | 87% | 2493 fps | 100% |
| Lovex S065 | <<locked>> | 92% | 53,577 psi | 86% | 2513 fps | 99.7% |
| Lovex S070 | <<locked>> | 94% | 54,563 psi | 87% | 2549 fps | 99.3% |
| Lovex S071ᴾ | <<locked>> | 100% | 39,842 psi | 64% | 2352 fps | 97.5% |
| Norma 201 | <<locked>> | 84% | 55,724 psi | 89% | 2507 fps | 100% |
| Norma 202 | <<locked>> | 84% | 56,347 psi | 90% | 2503 fps | 100% |
| Norma 203B | <<locked>> | 86% | 54,723 psi | 88% | 2546 fps | 100% |
| Norma 204 | <<locked>> | 94% | 52,765 psi | 85% | 2562 fps | 97.6% |
| Norma MRPᴾ | <<locked>> | 100% | 50,517 psi | 81% | 2631 fps | 98.8% |
| Norma URP | <<locked>> | 94% | 52,953 psi | 85% | 2569 fps | 100% |
| Ramshot Big Game | <<locked>> | 86% | 55,187 psi | 88% | 2572 fps | 100% |
| Ramshot Hunter | <<locked>> | 96% | 55,071 psi | 88% | 2618 fps | 99.7% |
| Ramshot TAC | <<locked>> | 82% | 55,811 psi | 89% | 2536 fps | 99.9% |
| Ramshot Wild Boar | <<locked>> | 82% | 55,695 psi | 89% | 2549 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,651 psi | 59% | 1572 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 88% | 56,434 psi | 90% | 2556 fps | 99.6% |
| ReloadSwiss RS 52 | <<locked>> | 84% | 56,260 psi | 90% | 2618 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 90% | 55,840 psi | 90% | 2651 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 94% | 53,519 psi | 86% | 2602 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 96% | 56,217 psi | 90% | 2680 fps | 100% |
| Rottweil R 902 | <<locked>> | 86% | 56,275 psi | 90% | 2507 fps | 100% |
| Rottweil R 903 | <<locked>> | 90% | 55,753 psi | 89% | 2546 fps | 100% |
| Rottweil R 904 | <<locked>> | 98% | 53,490 psi | 86% | 2539 fps | 96.7% |
| Rottweil R 905ᴾ | <<locked>> | 100% | 53,345 psi | 86% | 2595 fps | 98.1% |
| Rottweil R 907 | <<locked>> | 92% | 55,347 psi | 89% | 2539 fps | 98.9% |
| Shooters World Long Rifle | <<locked>> | 92% | 53,577 psi | 86% | 2513 fps | 99.7% |
| Shooters World Match Rifle | <<locked>> | 82% | 53,548 psi | 86% | 2490 fps | 100% |
| Shooters World Precision | <<locked>> | 86% | 54,099 psi | 87% | 2493 fps | 100% |
| Shooters World SW4350 | <<locked>> | 94% | 54,563 psi | 87% | 2549 fps | 99.3% |
| SNPE Vectan SP 11 | <<locked>> | 88% | 53,751 psi | 86% | 2556 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 82% | 54,331 psi | 87% | 2516 fps | 99.9% |
| SNPE Vectan SP 9 | <<locked>> | 84% | 55,332 psi | 89% | 2536 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 82% | 53,374 psi | 86% | 2398 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 88% | 53,925 psi | 86% | 2402 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 92% | 53,243 psi | 85% | 2470 fps | 99% |
| SNPE Vectan Tubal 8000ᴾ | <<locked>> | 100% | 52,852 psi | 85% | 2589 fps | 98% |
| Somchem S335 | <<locked>> | 84% | 56,347 psi | 90% | 2441 fps | 100% |
| Somchem S341 | <<locked>> | 82% | 54,056 psi | 87% | 2507 fps | 100% |
| Somchem S355 | <<locked>> | 90% | 55,753 psi | 89% | 2543 fps | 100% |
| Somchem S361 | <<locked>> | 98% | 55,259 psi | 89% | 2539 fps | 96.2% |
| Somchem S365 | <<locked>> | 98% | 54,940 psi | 88% | 2615 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 54,056 psi | 87% | 2572 fps | 98.8% |
| Vihtavuori N133 | <<locked>> | 82% | 53,853 psi | 86% | 2385 fps | 100% |
| Vihtavuori N135 | <<locked>> | 84% | 52,939 psi | 85% | 2425 fps | 100% |
| Vihtavuori N140 | <<locked>> | 84% | 53,403 psi | 86% | 2441 fps | 100% |
| Vihtavuori N150 | <<locked>> | 90% | 53,693 psi | 86% | 2480 fps | 100% |
| Vihtavuori N160 | <<locked>> | 94% | 55,216 psi | 89% | 2562 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 46,514 psi | 75% | 2451 fps | 97.1% |
| Vihtavuori N530 | <<locked>> | 82% | 56,202 psi | 90% | 2507 fps | 100% |
| Vihtavuori N540 | <<locked>> | 86% | 54,969 psi | 88% | 2484 fps | 100% |
| Vihtavuori N550 | <<locked>> | 94% | 54,128 psi | 87% | 2569 fps | 100% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 50,256 psi | 81% | 2572 fps | 100% |
| Winchester 6.5 StaBALL | <<locked>> | 94% | 54,737 psi | 88% | 2536 fps | 100% |
| Winchester 760 | <<locked>> | 92% | 52,939 psi | 85% | 2582 fps | 99.1% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 40,451 psi | 65% | 2546 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 84% | 55,390 psi | 89% | 2543 fps | 100% |
| Winchester Supreme 780ᴾ | <<locked>> | 100% | 50,517 psi | 81% | 2516 fps | 97.3% |
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 2495 | <<locked>> | 80% | 47,297 psi | 76% | 2356 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 45,643 psi | 73% | 2356 fps | 97.1% |
| Accurate 3100 | <<locked>> | 90% | 34,171 psi | 55% | 2241 fps | 95.8% |
| Accurate 4064 | <<locked>> | 80% | 44,773 psi | 72% | 2362 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 33,460 psi | 54% | 2234 fps | 97.4% |
| Accurate High Country | <<locked>> | 96% | 45,310 psi | 73% | 2546 fps | 95.3% |
| ADI AR 2206H | <<locked>> | 80% | 50,198 psi | 80% | 2467 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 42,786 psi | 69% | 2336 fps | 99.6% |
| ADI AR 2209 | <<locked>> | 92% | 42,670 psi | 68% | 2415 fps | 95.3% |
| ADI Benchmark 8208 | <<locked>> | 80% | 52,257 psi | 84% | 2461 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 46,340 psi | 74% | 2520 fps | 99.9% |
| Alliant Power Pro Varmint | <<locked>> | 92% | 42,699 psi | 68% | 2415 fps | 95.4% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 42,844 psi | 69% | 2359 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 45,759 psi | 73% | 2415 fps | 99.9% |
| Alliant Reloder-16 | 54.8 gr | 80% | 33,373 psi | 54% | 2244 fps | 97.5% |
| Alliant Reloder-17 | <<locked>> | 80% | 37,304 psi | 60% | 2356 fps | 99.6% |
| Alliant Reloder-19 | <<locked>> | 92% | 42,177 psi | 68% | 2408 fps | 95.4% |
| Alliant Reloder-22 | <<locked>> | 96% | 41,916 psi | 67% | 2451 fps | 95.5% |
| Alliant Reloder-23 | <<locked>> | 82% | 25,802 psi | 41% | 2077 fps | 95.7% |
| Alliant Reloder-25 | <<locked>> | 94% | 32,851 psi | 53% | 2274 fps | 95.6% |
| Alliant Reloder-26 | <<locked>> | 86% | 31,198 psi | 50% | 2277 fps | 95.9% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 49,705 psi | 80% | 2480 fps | 99.9% |
| Bofors RP15 | <<locked>> | 98% | 41,133 psi | 66% | 2434 fps | 95% |
| Bofors RP3 | <<locked>> | 80% | 42,989 psi | 69% | 2369 fps | 100% |
| Bofors RP5 | <<locked>> | 96% | 41,916 psi | 67% | 2451 fps | 95.5% |
| Bofors RP7 | <<locked>> | 80% | 38,174 psi | 61% | 2251 fps | 95.3% |
| Hodgdon BL-C2 | <<locked>> | 80% | 51,779 psi | 83% | 2490 fps | 100% |
| Hodgdon H380 | <<locked>> | 80% | 43,497 psi | 70% | 2375 fps | 99.1% |
| Hodgdon H414 | <<locked>> | 80% | 35,563 psi | 57% | 2274 fps | 95.1% |
| Hodgdon H4350 | <<locked>> | 82% | 41,307 psi | 66% | 2346 fps | 95.5% |
| Hodgdon H4895 | <<locked>> | 80% | 50,705 psi | 81% | 2474 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 30,792 psi | 49% | 2152 fps | 98.2% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 47,253 psi | 76% | 2461 fps | 100% |
| Hodgdon Superformance | 63.9 gr | 82% | 37,057 psi | 59% | 2333 fps | 95% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,079 psi | 43% | 1371 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 48,689 psi | 78% | 2431 fps | 100% |
| IMR 3031 | <<locked>> | 80% | 51,068 psi | 82% | 2454 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 44,947 psi | 72% | 2365 fps | 99.8% |
| IMR 4166 Enduron | <<locked>> | 80% | 47,268 psi | 76% | 2388 fps | 98.1% |
| IMR 4350 | <<locked>> | 84% | 38,450 psi | 62% | 2280 fps | 95.4% |
| IMR 4451 Enduron | <<locked>> | 80% | 39,639 psi | 64% | 2280 fps | 96.2% |
| IMR 4831 | <<locked>> | 80% | 32,489 psi | 52% | 2195 fps | 97.1% |
| IMR 4895 | <<locked>> | 80% | 46,934 psi | 75% | 2441 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 98% | 51,517 psi | 83% | 2507 fps | 95.7% |
| IMR 8208 XBR | <<locked>> | 80% | 52,257 psi | 84% | 2461 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 50,227 psi | 81% | 2444 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 49,617 psi | 80% | 2402 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 45,049 psi | 72% | 2365 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 37,101 psi | 59% | 2238 fps | 97% |
| Lovex S070 | <<locked>> | 80% | 35,273 psi | 57% | 2218 fps | 95.2% |
| Lovex S071 | <<locked>> | 94% | 32,895 psi | 53% | 2211 fps | 95.3% |
| Norma 201 | <<locked>> | 80% | 49,197 psi | 79% | 2418 fps | 100% |
| Norma 202 | <<locked>> | 80% | 49,661 psi | 80% | 2415 fps | 100% |
| Norma 203B | <<locked>> | 80% | 45,136 psi | 72% | 2405 fps | 99.9% |
| Norma 204 | <<locked>> | 88% | 43,323 psi | 69% | 2408 fps | 95.4% |
| Norma MRP | <<locked>> | 92% | 38,580 psi | 62% | 2415 fps | 95.9% |
| Norma URP | <<locked>> | 80% | 33,591 psi | 54% | 2231 fps | 97.3% |
| Ramshot Big Game | <<locked>> | 80% | 45,092 psi | 72% | 2425 fps | 99.9% |
| Ramshot Hunter | <<locked>> | 80% | 32,706 psi | 52% | 2218 fps | 95% |
| Ramshot TAC | <<locked>> | 80% | 52,112 psi | 84% | 2487 fps | 99.7% |
| Ramshot Wild Boar | <<locked>> | 80% | 52,156 psi | 84% | 2500 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,398 psi | 44% | 1404 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 43,569 psi | 70% | 2359 fps | 97.9% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 49,168 psi | 79% | 2520 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 39,653 psi | 64% | 2408 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 33,098 psi | 53% | 2247 fps | 96.9% |
| ReloadSwiss RS 70 | 59.9 gr | 80% | 32,706 psi | 52% | 2251 fps | 96% |
| Rottweil R 902 | <<locked>> | 80% | 46,847 psi | 75% | 2375 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 40,350 psi | 65% | 2320 fps | 99.9% |
| Rottweil R 904 | <<locked>> | 94% | 47,311 psi | 76% | 2448 fps | 95.4% |
| Rottweil R 905 | <<locked>> | 92% | 41,002 psi | 66% | 2392 fps | 95.3% |
| Rottweil R 907 | <<locked>> | 80% | 38,174 psi | 61% | 2251 fps | 95.3% |
| Shooters World Long Rifle | <<locked>> | 80% | 37,101 psi | 59% | 2238 fps | 97% |
| Shooters World Match Rifle | <<locked>> | 80% | 50,227 psi | 81% | 2444 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 45,049 psi | 72% | 2365 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 35,273 psi | 57% | 2218 fps | 95.2% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 41,379 psi | 66% | 2369 fps | 99.7% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 50,836 psi | 82% | 2467 fps | 99.8% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 48,733 psi | 78% | 2444 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 50,314 psi | 81% | 2359 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 42,279 psi | 68% | 2244 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 36,361 psi | 58% | 2188 fps | 95.4% |
| SNPE Vectan Tubal 8000 | <<locked>> | 92% | 40,611 psi | 65% | 2388 fps | 95.1% |
| Somchem S335 | <<locked>> | 80% | 49,893 psi | 80% | 2359 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 50,560 psi | 81% | 2457 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 40,930 psi | 66% | 2320 fps | 99.8% |
| Somchem S361 | <<locked>> | 96% | 51,735 psi | 83% | 2487 fps | 95.4% |
| Somchem S365 | <<locked>> | 80% | 30,182 psi | 48% | 2195 fps | 99.1% |
| Somchem S385 | <<locked>> | 90% | 39,131 psi | 63% | 2333 fps | 95.6% |
| Vihtavuori N133 | <<locked>> | 80% | 50,778 psi | 81% | 2346 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 46,920 psi | 75% | 2346 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 47,094 psi | 76% | 2359 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 38,943 psi | 62% | 2260 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 34,940 psi | 56% | 2231 fps | 97.6% |
| Vihtavuori N165 | <<locked>> | 96% | 40,886 psi | 66% | 2356 fps | 95.6% |
| Vihtavuori N530 | <<locked>> | 80% | 52,750 psi | 85% | 2464 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 45,498 psi | 73% | 2356 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 34,534 psi | 55% | 2234 fps | 97.3% |
| Vihtavuori N555 | <<locked>> | 82% | 27,920 psi | 45% | 2142 fps | 95.9% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 34,287 psi | 55% | 2208 fps | 99.2% |
| Winchester 760 | <<locked>> | 80% | 35,723 psi | 57% | 2277 fps | 95.2% |
| Winchester StaBALL HD | <<locked>> | 84% | 24,221 psi | 39% | 2093 fps | 95% |
| Winchester StaBALL Match | <<locked>> | 80% | 48,457 psi | 78% | 2448 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 96% | 44,034 psi | 71% | 2411 fps | 95.7% |
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 104 powders for .338 Win Mag. loaded with the .338 | 250gr | Speer Grand Slam. ReloadSwiss RS 70 delivers the highest muzzle velocity at 2,680 fps; across all powders the maximum-charge window runs from 1,539 fps to 2,680 fps. Accurate 3100 gives the best case fill at 100 %, and 104 of the 104 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (430 MPa), the top charges use 58–90 %, 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, Accurate High Country, ADI AR 2209 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 70, Alliant Reloder-16, Hodgdon Superformance rank at the top here: for .338 Win Mag. with the .338 | 250gr | Speer Grand Slam 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.