Load Specifications
Load data in caliber .338 Norma Mag. with .338 | 250gr | Sierra GameKing bullet and 82 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Winchester StaBALL HD, IMR 7828 SSC and Vihtavuori N560.
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.
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Max Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 96% | 55,288 psi | 87% | 2648 fps | 100% |
| Accurate 4350 | <<locked>> | 88% | 56,942 psi | 89% | 2680 fps | 100% |
| Accurate High Country | <<locked>> | 94% | 56,666 psi | 89% | 2789 fps | 99.2% |
| Accurate MAGPRO | <<locked>> | 96% | 57,464 psi | 90% | 2792 fps | 98.4% |
| ADI AR 2208 | <<locked>> | 82% | 54,882 psi | 86% | 2592 fps | 100% |
| ADI AR 2209 | <<locked>> | 94% | 57,682 psi | 90% | 2733 fps | 99.7% |
| ADI AR 2213 | <<locked>> | 96% | 55,288 psi | 87% | 2736 fps | 98.8% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 46,151 psi | 72% | 2582 fps | 97.4% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 40,973 psi | 64% | 2546 fps | 99% |
| Alliant Power Pro Varmint | <<locked>> | 94% | 57,740 psi | 90% | 2730 fps | 99.7% |
| Alliant Reloder- TS 15.5 | <<locked>> | 82% | 56,028 psi | 88% | 2612 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 90% | 57,682 psi | 90% | 2726 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 84% | 55,158 psi | 86% | 2694 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 94% | 56,985 psi | 89% | 2720 fps | 99.6% |
| Alliant Reloder-22 | <<locked>> | 96% | 55,056 psi | 86% | 2733 fps | 99.6% |
| Alliant Reloder-23 | <<locked>> | 98% | 55,883 psi | 88% | 2700 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 51,692 psi | 81% | 2710 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 94% | 56,463 psi | 88% | 2792 fps | 100% |
| Baschieri & Pellagri 109 | <<locked>> | 98% | 57,276 psi | 90% | 2697 fps | 96.6% |
| Bofors RP15ᴾ | <<locked>> | 100% | 57,580 psi | 90% | 2766 fps | 99.7% |
| Bofors RP3 | <<locked>> | 82% | 57,188 psi | 90% | 2631 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 47,485 psi | 74% | 2648 fps | 98.1% |
| Bofors RP5 | <<locked>> | 96% | 55,056 psi | 86% | 2733 fps | 99.6% |
| Bofors RP7 | <<locked>> | 86% | 56,101 psi | 88% | 2631 fps | 99.8% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 50,865 psi | 80% | 2664 fps | 98.9% |
| Hodgdon H380 | <<locked>> | 82% | 57,087 psi | 89% | 2651 fps | 100% |
| Hodgdon H414 | <<locked>> | 86% | 54,969 psi | 86% | 2677 fps | 100% |
| Hodgdon H4350 | <<locked>> | 84% | 54,302 psi | 85% | 2638 fps | 99.5% |
| Hodgdon H4831 | <<locked>> | 94% | 55,201 psi | 87% | 2677 fps | 98.3% |
| Hodgdon H4831 SC | <<locked>> | 94% | 54,172 psi | 85% | 2661 fps | 98.1% |
| Hodgdon Hybrid 100V | <<locked>> | 90% | 54,433 psi | 85% | 2608 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 50,560 psi | 79% | 2766 fps | 99.7% |
| Hodgdon Superformance | <<locked>> | 86% | 55,259 psi | 87% | 2717 fps | 99.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,956 psi | 58% | 1637 fps | 100% |
| IMR 4350 | <<locked>> | 90% | 57,435 psi | 90% | 2664 fps | 99.9% |
| IMR 4451 Enduron | <<locked>> | 86% | 57,609 psi | 90% | 2651 fps | 100% |
| IMR 4831 | <<locked>> | 90% | 57,116 psi | 90% | 2667 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 94% | 56,565 psi | 89% | 2664 fps | 98.6% |
| IMR 7828 SSC | <<locked>> | 98% | 56,753 psi | 89% | 2769 fps | 99.1% |
| Lovex S065 | <<locked>> | 86% | 54,563 psi | 86% | 2602 fps | 100% |
| Lovex S070 | <<locked>> | 88% | 56,188 psi | 88% | 2648 fps | 100% |
| Lovex S071ᴾ | <<locked>> | 100% | 52,620 psi | 82% | 2612 fps | 100% |
| Norma 204 | <<locked>> | 88% | 54,752 psi | 86% | 2667 fps | 99.3% |
| Norma 217ᴾ | <<locked>> | 100% | 36,463 psi | 57% | 2474 fps | 97.1% |
| Norma MRP | <<locked>> | 94% | 54,752 psi | 86% | 2753 fps | 100% |
| Norma URP | <<locked>> | 88% | 55,419 psi | 87% | 2664 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 57,551 psi | 90% | 2789 fps | 99.4% |
| Ramshot Hunter | <<locked>> | 88% | 54,114 psi | 85% | 2667 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 55,593 psi | 87% | 2726 fps | 99.9% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,811 psi | 59% | 1680 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 56,927 psi | 89% | 2641 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 82% | 54,665 psi | 86% | 2680 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 56,913 psi | 89% | 2703 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 88% | 55,085 psi | 86% | 2730 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 50,981 psi | 80% | 2766 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 45,803 psi | 72% | 2651 fps | 96.2% |
| Rottweil R 903 | <<locked>> | 84% | 57,276 psi | 90% | 2628 fps | 100% |
| Rottweil R 904 | <<locked>> | 92% | 55,463 psi | 87% | 2651 fps | 98.8% |
| Rottweil R 905 | <<locked>> | 94% | 56,492 psi | 89% | 2710 fps | 99.6% |
| Rottweil R 907 | <<locked>> | 86% | 56,101 psi | 88% | 2631 fps | 99.8% |
| Shooters World Long Rifle | <<locked>> | 86% | 54,563 psi | 86% | 2602 fps | 100% |
| Shooters World SW4350 | <<locked>> | 88% | 56,188 psi | 88% | 2648 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 82% | 55,129 psi | 86% | 2638 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 57,479 psi | 90% | 2507 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 57,551 psi | 90% | 2608 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 56,028 psi | 88% | 2707 fps | 99.6% |
| Somchem S355 | <<locked>> | 84% | 56,913 psi | 89% | 2621 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 56,956 psi | 89% | 2648 fps | 98.4% |
| Somchem S365 | <<locked>> | 90% | 55,405 psi | 87% | 2664 fps | 100% |
| Somchem S385 | <<locked>> | 94% | 57,043 psi | 89% | 2684 fps | 99.9% |
| Vihtavuori N150 | <<locked>> | 84% | 54,650 psi | 86% | 2552 fps | 100% |
| Vihtavuori N160 | <<locked>> | 88% | 57,246 psi | 90% | 2654 fps | 100% |
| Vihtavuori N165 | <<locked>> | 98% | 56,492 psi | 89% | 2664 fps | 99.8% |
| Vihtavuori N550 | <<locked>> | 88% | 56,434 psi | 88% | 2664 fps | 100% |
| Vihtavuori N555 | <<locked>> | 94% | 54,795 psi | 86% | 2680 fps | 100% |
| Vihtavuori N560 | <<locked>> | 94% | 54,752 psi | 86% | 2749 fps | 98.5% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 54,157 psi | 85% | 2726 fps | 98.6% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 47,224 psi | 74% | 2661 fps | 96% |
| Winchester 6.5 StaBALL | <<locked>> | 88% | 56,681 psi | 89% | 2618 fps | 100% |
| Winchester 760 | <<locked>> | 86% | 55,172 psi | 86% | 2680 fps | 100% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 57,043 psi | 89% | 2831 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 96% | 57,159 psi | 90% | 2684 fps | 99.6% |
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 3100 | <<locked>> | 80% | 32,343 psi | 51% | 2247 fps | 97% |
| Accurate 4350 | <<locked>> | 80% | 43,555 psi | 68% | 2480 fps | 100% |
| Accurate High Country | <<locked>> | 84% | 40,016 psi | 63% | 2503 fps | 95.7% |
| Accurate MAGPRO | <<locked>> | 88% | 43,410 psi | 68% | 2559 fps | 95.3% |
| ADI AR 2208 | <<locked>> | 80% | 51,605 psi | 81% | 2546 fps | 100% |
| ADI AR 2209 | <<locked>> | 80% | 36,405 psi | 57% | 2362 fps | 95.5% |
| ADI AR 2213 | <<locked>> | 86% | 39,595 psi | 62% | 2457 fps | 95.1% |
| ADI AR 2217 | <<locked>> | 96% | 40,553 psi | 64% | 2470 fps | 95.7% |
| ADI AR 2225 | <<locked>> | 92% | 31,778 psi | 50% | 2326 fps | 95.5% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 36,738 psi | 58% | 2365 fps | 95.7% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 52,692 psi | 83% | 2569 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 41,640 psi | 65% | 2484 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 80% | 48,008 psi | 75% | 2595 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 36,405 psi | 57% | 2359 fps | 95.6% |
| Alliant Reloder-22 | <<locked>> | 82% | 34,461 psi | 54% | 2356 fps | 95% |
| Alliant Reloder-23 | <<locked>> | 80% | 30,937 psi | 48% | 2274 fps | 99.4% |
| Alliant Reloder-25 | <<locked>> | 80% | 27,151 psi | 43% | 2185 fps | 95% |
| Alliant Reloder-26 | <<locked>> | 80% | 33,562 psi | 53% | 2395 fps | 98.7% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 50,778 psi | 80% | 2595 fps | 95% |
| Bofors RP15 | <<locked>> | 86% | 36,593 psi | 57% | 2402 fps | 95.6% |
| Bofors RP3 | <<locked>> | 80% | 53,476 psi | 84% | 2582 fps | 100% |
| Bofors RP30 | <<locked>> | 94% | 38,870 psi | 61% | 2484 fps | 95.8% |
| Bofors RP5 | <<locked>> | 82% | 34,461 psi | 54% | 2356 fps | 95% |
| Bofors RP7 | <<locked>> | 80% | 46,586 psi | 73% | 2484 fps | 99% |
| Hodgdon H1000 | <<locked>> | 92% | 38,870 psi | 61% | 2441 fps | 95.8% |
| Hodgdon H380 | <<locked>> | 80% | 53,650 psi | 84% | 2602 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 45,194 psi | 71% | 2523 fps | 99.2% |
| Hodgdon H4350 | <<locked>> | 80% | 47,790 psi | 75% | 2536 fps | 98.7% |
| Hodgdon H4831 | <<locked>> | 86% | 42,308 psi | 66% | 2464 fps | 95.4% |
| Hodgdon H4831 SC | <<locked>> | 86% | 41,495 psi | 65% | 2448 fps | 95.1% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 39,363 psi | 62% | 2379 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 88% | 34,200 psi | 54% | 2415 fps | 95.2% |
| Hodgdon Superformance | <<locked>> | 80% | 44,295 psi | 69% | 2543 fps | 98.9% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,615 psi | 43% | 1463 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 42,090 psi | 66% | 2421 fps | 98.2% |
| IMR 4451 Enduron | <<locked>> | 80% | 47,834 psi | 75% | 2507 fps | 99.4% |
| IMR 4831 | <<locked>> | 80% | 41,437 psi | 65% | 2431 fps | 99.9% |
| IMR 4955 Enduron | <<locked>> | 84% | 41,350 psi | 65% | 2411 fps | 95.3% |
| IMR 7828 SSC | 76.8 gr | 88% | 40,509 psi | 63% | 2490 fps | 95.6% |
| Lovex S065 | <<locked>> | 80% | 45,411 psi | 71% | 2461 fps | 99.7% |
| Lovex S070 | <<locked>> | 80% | 43,772 psi | 69% | 2451 fps | 99% |
| Lovex S071 | <<locked>> | 80% | 27,862 psi | 44% | 2136 fps | 95% |
| Norma 204 | <<locked>> | 80% | 41,756 psi | 65% | 2451 fps | 97.1% |
| Norma 217 | <<locked>> | 96% | 32,097 psi | 50% | 2365 fps | 95.2% |
| Norma MRP | <<locked>> | 80% | 33,562 psi | 53% | 2362 fps | 96.2% |
| Norma URP | <<locked>> | 80% | 42,786 psi | 67% | 2467 fps | 99.9% |
| Ramshot Grand | <<locked>> | 88% | 40,277 psi | 63% | 2497 fps | 95.9% |
| Ramshot Hunter | <<locked>> | 80% | 41,524 psi | 65% | 2464 fps | 99.1% |
| Ramshot Magnum | <<locked>> | 86% | 33,359 psi | 52% | 2326 fps | 95.3% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,282 psi | 44% | 1499 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 53,185 psi | 83% | 2589 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 50,952 psi | 80% | 2635 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 43,294 psi | 68% | 2497 fps | 99.9% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 41,582 psi | 65% | 2513 fps | 99.8% |
| ReloadSwiss RS 76 | <<locked>> | 88% | 33,301 psi | 52% | 2395 fps | 96.2% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 42,540 psi | 67% | 2589 fps | 95.2% |
| Rottweil R 903 | <<locked>> | 80% | 50,459 psi | 79% | 2536 fps | 100% |
| Rottweil R 904 | <<locked>> | 82% | 40,335 psi | 63% | 2395 fps | 95.6% |
| Rottweil R 905 | <<locked>> | 80% | 35,563 psi | 56% | 2343 fps | 95.5% |
| Rottweil R 907 | <<locked>> | 80% | 46,586 psi | 73% | 2484 fps | 99% |
| Shooters World Long Rifle | <<locked>> | 80% | 45,411 psi | 71% | 2461 fps | 99.7% |
| Shooters World SW4350 | <<locked>> | 80% | 43,772 psi | 69% | 2451 fps | 99% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 51,619 psi | 81% | 2589 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 50,865 psi | 80% | 2425 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 44,483 psi | 70% | 2411 fps | 99% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 35,244 psi | 55% | 2339 fps | 95.3% |
| Somchem S355 | <<locked>> | 80% | 50,299 psi | 79% | 2533 fps | 100% |
| Somchem S361 | <<locked>> | 84% | 43,787 psi | 69% | 2438 fps | 95.7% |
| Somchem S365 | <<locked>> | 80% | 39,639 psi | 62% | 2431 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 36,172 psi | 57% | 2329 fps | 96.6% |
| Vihtavuori N150 | <<locked>> | 80% | 48,167 psi | 75% | 2464 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 44,251 psi | 69% | 2464 fps | 100% |
| Vihtavuori N165 | <<locked>> | 82% | 33,417 psi | 52% | 2264 fps | 95.2% |
| Vihtavuori N550 | <<locked>> | 80% | 43,598 psi | 68% | 2467 fps | 99.9% |
| Vihtavuori N555 | <<locked>> | 80% | 34,751 psi | 54% | 2343 fps | 99.4% |
| Vihtavuori N560 | 78 gr | 86% | 41,568 psi | 65% | 2520 fps | 95.4% |
| Vihtavuori N565 | <<locked>> | 92% | 41,408 psi | 65% | 2510 fps | 95.7% |
| Vihtavuori N568 | <<locked>> | 98% | 44,092 psi | 69% | 2602 fps | 95% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 43,047 psi | 67% | 2428 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 45,194 psi | 71% | 2523 fps | 99.2% |
| Winchester StaBALL HD | 71.8 gr | 80% | 27,441 psi | 43% | 2280 fps | 99.5% |
| Winchester Supreme 780 | <<locked>> | 82% | 35,259 psi | 55% | 2310 fps | 95.1% |
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 82 powders for .338 Norma Mag. loaded with the .338 | 250gr | Sierra GameKing. Winchester StaBALL HD delivers the highest muzzle velocity at 2,831 fps; across all powders the maximum-charge window runs from 1,637 fps to 2,831 fps. ADI AR 2217 gives the best case fill at 100 %, and 82 of the 82 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 57–90 %, leaving at least 10 % headroom. The 250.0 gr projectile in 0.338" calls for a 1:14.0 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2225, Alliant Reloder-25 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. Winchester StaBALL HD, IMR 7828 SSC, Vihtavuori N560 rank at the top here: for .338 Norma Mag. with the .338 | 250gr | 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.