Load Specifications
Load data in caliber .338 Lapua Mag. Ackley Improved with .338 | 300gr | Berger Hybrid OTM bullet and 74 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Vihtavuori N570, Hodgdon Retumbo and ReloadSwiss RS 76.
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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You can find more information in our FAQ: How can I use the Personalized Load Calculator?
Max Load - Barrel Length: 27"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 88% | 59,524 psi | 86% | 2589 fps | 100% |
| Accurate 8700ᴾ | <<locked>> | 100% | 46,166 psi | 66% | 2543 fps | 98.1% |
| Accurate MAGPRO | <<locked>> | 88% | 59,408 psi | 85% | 2723 fps | 100% |
| ADI APS 450 | <<locked>> | 82% | 61,540 psi | 88% | 2018 fps | 100% |
| ADI AR 2209 | <<locked>> | 86% | 60,756 psi | 87% | 2674 fps | 100% |
| ADI AR 2213 | <<locked>> | 88% | 59,292 psi | 85% | 2700 fps | 100% |
| ADI AR 2217 | <<locked>> | 98% | 62,120 psi | 89% | 2730 fps | 100% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 58,175 psi | 84% | 2825 fps | 100% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 60,901 psi | 87% | 2749 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 82% | 61,061 psi | 88% | 2641 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 86% | 60,234 psi | 87% | 2664 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 88% | 59,683 psi | 86% | 2690 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 90% | 61,728 psi | 89% | 2635 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 94% | 62,221 psi | 89% | 2717 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 84% | 58,740 psi | 84% | 2684 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 98% | 60,176 psi | 86% | 2799 fps | 99.9% |
| Alliant Reloder-50ᴾ | <<locked>> | 100% | 55,492 psi | 80% | 2736 fps | 99.5% |
| Baschieri & Pellagri 109 | <<locked>> | 90% | 59,190 psi | 85% | 2667 fps | 99.9% |
| Bofors RP15 | <<locked>> | 92% | 62,787 psi | 90% | 2730 fps | 100% |
| Bofors RP30 | <<locked>> | 96% | 61,931 psi | 89% | 2749 fps | 100% |
| Bofors RP5 | <<locked>> | 88% | 59,683 psi | 86% | 2690 fps | 100% |
| Hodgdon H1000 | <<locked>> | 96% | 59,756 psi | 86% | 2700 fps | 100% |
| Hodgdon H4350 | <<locked>> | 82% | 61,569 psi | 88% | 2641 fps | 100% |
| Hodgdon H4831 | <<locked>> | 92% | 61,888 psi | 89% | 2684 fps | 100% |
| Hodgdon H4831 SC | <<locked>> | 88% | 60,930 psi | 88% | 2671 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 84% | 61,134 psi | 88% | 2566 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 94% | 61,757 psi | 89% | 2812 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,898 psi | 54% | 1617 fps | 100% |
| IMR 4350 | <<locked>> | 84% | 62,642 psi | 90% | 2631 fps | 100% |
| IMR 4831 | <<locked>> | 86% | 61,685 psi | 89% | 2605 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 88% | 61,917 psi | 89% | 2654 fps | 100% |
| IMR 7828 SSC | <<locked>> | 88% | 61,830 psi | 89% | 2736 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 94% | 60,553 psi | 87% | 2625 fps | 98.2% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 55,825 psi | 80% | 2694 fps | 100% |
| Lovex D100 | <<locked>> | 98% | 61,221 psi | 88% | 2680 fps | 97.5% |
| Lovex S065 | <<locked>> | 82% | 62,671 psi | 90% | 2598 fps | 100% |
| Lovex S070 | <<locked>> | 82% | 61,221 psi | 88% | 2608 fps | 100% |
| Lovex S071 | <<locked>> | 94% | 61,235 psi | 88% | 2608 fps | 100% |
| Norma 204 | <<locked>> | 82% | 60,466 psi | 87% | 2651 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 57,188 psi | 82% | 2710 fps | 100% |
| Norma MRP | <<locked>> | 86% | 59,944 psi | 86% | 2703 fps | 100% |
| Norma URP | <<locked>> | 82% | 61,540 psi | 88% | 2621 fps | 100% |
| Ramshot Grand | <<locked>> | 86% | 62,366 psi | 90% | 2743 fps | 100% |
| Ramshot Hunter | <<locked>> | 82% | 60,524 psi | 87% | 2641 fps | 100% |
| Ramshot LRTᴾ | <<locked>> | 100% | 57,682 psi | 83% | 2753 fps | 96.9% |
| Ramshot Magnum | <<locked>> | 88% | 59,117 psi | 85% | 2661 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,957 psi | 56% | 1657 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 82% | 62,932 psi | 90% | 2697 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 94% | 62,917 psi | 90% | 2805 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 96% | 61,801 psi | 89% | 2792 fps | 100% |
| Rottweil R 904 | <<locked>> | 86% | 61,003 psi | 88% | 2641 fps | 100% |
| Rottweil R 905 | <<locked>> | 86% | 60,147 psi | 86% | 2657 fps | 100% |
| Shooters World 50 BMG | <<locked>> | 98% | 61,221 psi | 88% | 2680 fps | 97.5% |
| Shooters World Long Rifle | <<locked>> | 82% | 62,671 psi | 90% | 2598 fps | 100% |
| Shooters World SW4350 | <<locked>> | 82% | 61,221 psi | 88% | 2608 fps | 100% |
| SNPE Vectan SP 13ᴾ | <<locked>> | 100% | 48,269 psi | 69% | 2552 fps | 98.1% |
| SNPE Vectan Tubal 7000 | <<locked>> | 82% | 61,496 psi | 88% | 2562 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 86% | 59,741 psi | 86% | 2654 fps | 100% |
| Somchem S361 | <<locked>> | 86% | 62,410 psi | 90% | 2638 fps | 100% |
| Somchem S365 | <<locked>> | 82% | 59,640 psi | 86% | 2579 fps | 100% |
| Somchem S385 | <<locked>> | 86% | 60,234 psi | 87% | 2621 fps | 100% |
| Vihtavuori 20N29ᴾ | <<locked>> | 100% | 46,093 psi | 66% | 2539 fps | 96.1% |
| Vihtavuori 24N41ᴾ | <<locked>> | 100% | 58,494 psi | 84% | 2717 fps | 96.8% |
| Vihtavuori N150 | <<locked>> | 82% | 60,133 psi | 86% | 2503 fps | 100% |
| Vihtavuori N165 | <<locked>> | 92% | 62,149 psi | 89% | 2635 fps | 100% |
| Vihtavuori N170ᴾ | <<locked>> | 100% | 60,872 psi | 87% | 2687 fps | 99.3% |
| Vihtavuori N555 | <<locked>> | 86% | 59,756 psi | 86% | 2615 fps | 100% |
| Vihtavuori N560 | <<locked>> | 88% | 60,176 psi | 86% | 2730 fps | 100% |
| Vihtavuori N565 | <<locked>> | 92% | 60,162 psi | 86% | 2710 fps | 100% |
| Vihtavuori N568 | <<locked>> | 96% | 62,033 psi | 89% | 2785 fps | 100% |
| Vihtavuori N570 | <<locked>> | 96% | 59,756 psi | 86% | 2802 fps | 99.8% |
| Winchester 6.5 StaBALL | <<locked>> | 82% | 62,555 psi | 90% | 2562 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 90% | 62,859 psi | 90% | 2733 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 86% | 61,540 psi | 88% | 2644 fps | 100% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 27"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 80% | 45,847 psi | 66% | 2411 fps | 100% |
| Accurate 8700 | <<locked>> | 94% | 37,333 psi | 54% | 2375 fps | 95.5% |
| Accurate MAGPRO | <<locked>> | 80% | 45,179 psi | 65% | 2510 fps | 99.1% |
| ADI APS 450 | <<locked>> | 80% | 59,480 psi | 85% | 1991 fps | 100% |
| ADI AR 2209 | <<locked>> | 80% | 49,864 psi | 72% | 2526 fps | 100% |
| ADI AR 2213 | <<locked>> | 80% | 45,165 psi | 65% | 2493 fps | 99.8% |
| ADI AR 2217 | <<locked>> | 80% | 33,765 psi | 49% | 2277 fps | 98.3% |
| ADI AR 2218 | <<locked>> | 86% | 35,259 psi | 51% | 2392 fps | 95.1% |
| ADI AR 2225 | <<locked>> | 80% | 31,009 psi | 45% | 2260 fps | 99.7% |
| Alliant Reloder-16 | <<locked>> | 80% | 57,305 psi | 82% | 2595 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 49,763 psi | 71% | 2523 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 80% | 45,919 psi | 66% | 2493 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 80% | 44,773 psi | 64% | 2421 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 38,870 psi | 56% | 2388 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 80% | 50,850 psi | 73% | 2582 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 84% | 35,955 psi | 52% | 2388 fps | 95.7% |
| Alliant Reloder-50 | <<locked>> | 88% | 35,810 psi | 51% | 2385 fps | 95.1% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 43,149 psi | 62% | 2418 fps | 97.9% |
| Bofors RP15 | <<locked>> | 80% | 42,801 psi | 61% | 2441 fps | 99.9% |
| Bofors RP30 | <<locked>> | 80% | 36,361 psi | 52% | 2349 fps | 99% |
| Bofors RP5 | <<locked>> | 80% | 45,919 psi | 66% | 2493 fps | 100% |
| Hodgdon H1000 | <<locked>> | 80% | 34,650 psi | 50% | 2300 fps | 99% |
| Hodgdon H4350 | <<locked>> | 80% | 57,914 psi | 83% | 2595 fps | 100% |
| Hodgdon H4831 | <<locked>> | 80% | 42,090 psi | 60% | 2392 fps | 99.2% |
| Hodgdon H4831 SC | <<locked>> | 80% | 46,818 psi | 67% | 2474 fps | 99.7% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 53,853 psi | 77% | 2480 fps | 100% |
| Hodgdon Retumbo | 82.9 gr | 80% | 38,000 psi | 55% | 2451 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,543 psi | 41% | 1444 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 55,376 psi | 80% | 2543 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 51,372 psi | 74% | 2477 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 48,327 psi | 69% | 2467 fps | 99.8% |
| IMR 7828 SSC | <<locked>> | 80% | 46,775 psi | 67% | 2530 fps | 99.9% |
| IMR 7977 Enduron | <<locked>> | 86% | 46,949 psi | 67% | 2425 fps | 95.6% |
| IMR 8133 Enduron | <<locked>> | 80% | 28,631 psi | 41% | 2192 fps | 96.4% |
| Lovex D100 | <<locked>> | 92% | 49,632 psi | 71% | 2520 fps | 95.2% |
| Lovex S065 | <<locked>> | 80% | 59,045 psi | 85% | 2556 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 57,667 psi | 83% | 2566 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 39,682 psi | 57% | 2310 fps | 100% |
| Norma 204 | <<locked>> | 80% | 56,666 psi | 81% | 2602 fps | 100% |
| Norma 217 | <<locked>> | 80% | 28,834 psi | 41% | 2215 fps | 98.6% |
| Norma MRP | <<locked>> | 80% | 48,892 psi | 70% | 2556 fps | 100% |
| Norma URP | <<locked>> | 80% | 57,812 psi | 83% | 2579 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 49,719 psi | 71% | 2579 fps | 100% |
| Ramshot Hunter | <<locked>> | 80% | 56,797 psi | 82% | 2595 fps | 100% |
| Ramshot LRT | <<locked>> | 96% | 50,169 psi | 72% | 2635 fps | 95.2% |
| Ramshot Magnum | <<locked>> | 80% | 43,714 psi | 63% | 2451 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,283 psi | 42% | 1480 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 58,871 psi | 85% | 2651 fps | 100% |
| ReloadSwiss RS 76 | 88.7 gr | 80% | 37,159 psi | 53% | 2428 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 80% | 34,156 psi | 49% | 2339 fps | 97.3% |
| Rottweil R 904 | <<locked>> | 80% | 50,502 psi | 73% | 2500 fps | 100% |
| Rottweil R 905 | <<locked>> | 80% | 49,400 psi | 71% | 2513 fps | 100% |
| Shooters World 50 BMG | <<locked>> | 92% | 49,632 psi | 71% | 2520 fps | 95.2% |
| Shooters World Long Rifle | <<locked>> | 80% | 59,045 psi | 85% | 2556 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 57,667 psi | 83% | 2566 fps | 100% |
| SNPE Vectan SP 13 | <<locked>> | 94% | 39,436 psi | 57% | 2395 fps | 95.8% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 57,812 psi | 83% | 2520 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 49,066 psi | 70% | 2510 fps | 100% |
| Somchem S361 | <<locked>> | 80% | 51,474 psi | 74% | 2497 fps | 99.9% |
| Somchem S365 | <<locked>> | 80% | 55,811 psi | 80% | 2533 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 49,821 psi | 72% | 2487 fps | 100% |
| Vihtavuori 20N29 | <<locked>> | 98% | 42,873 psi | 62% | 2484 fps | 95.2% |
| Vihtavuori 24N41 | <<locked>> | 96% | 50,705 psi | 73% | 2598 fps | 95% |
| Vihtavuori N150 | <<locked>> | 80% | 56,565 psi | 81% | 2461 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 42,467 psi | 61% | 2365 fps | 100% |
| Vihtavuori N170 | <<locked>> | 86% | 39,189 psi | 56% | 2339 fps | 95% |
| Vihtavuori N555 | <<locked>> | 80% | 49,545 psi | 71% | 2487 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 46,166 psi | 66% | 2523 fps | 99.8% |
| Vihtavuori N565 | <<locked>> | 80% | 40,408 psi | 58% | 2408 fps | 99.2% |
| Vihtavuori N568 | <<locked>> | 80% | 35,433 psi | 51% | 2352 fps | 97.1% |
| Vihtavuori N570 | 89.1 gr | 82% | 36,289 psi | 52% | 2402 fps | 95.4% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 58,378 psi | 84% | 2516 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 43,656 psi | 63% | 2493 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 50,038 psi | 72% | 2497 fps | 100% |
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 76 powders for .338 Lapua Mag. Ackley Improved loaded with the .338 | 300gr | Berger Hybrid OTM. ADI AR 2218 delivers the highest muzzle velocity at 2,825 fps; across all powders the maximum-charge window runs from 1,617 fps to 2,825 fps. Accurate 8700 gives the best case fill at 100 %, and 76 of the 76 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (480 MPa), the top charges use 54–90 %, leaving at least 10 % headroom. The 300.0 gr projectile in 0.338" calls for a 1:11.0 twist; slower twists will usually not stabilise this weight. Accurate 8700, ADI AR 2218, ADI AR 2225 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. Vihtavuori N570, Hodgdon Retumbo, ReloadSwiss RS 76 rank at the top here: for .338 Lapua Mag. Ackley Improved with the .338 | 300gr | Berger Hybrid OTM they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Hodgdon 50BMG burn incompletely and react more sensitively to barrel length and temperature. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.