Load Specifications
Load data in caliber .338 Lapua Mag. Ackley Improved with .338 | 280gr | Barnes LRX BT bullet and 80 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Hodgdon Retumbo, ReloadSwiss RS 76 and Vihtavuori N570.
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>> | 92% | 61,844 psi | 89% | 2707 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 62,511 psi | 90% | 2720 fps | 100% |
| Accurate MAGPRO | <<locked>> | 92% | 62,033 psi | 89% | 2848 fps | 100% |
| ADI APS 450 | <<locked>> | 82% | 61,293 psi | 88% | 2073 fps | 100% |
| ADI AR 2209 | <<locked>> | 88% | 59,654 psi | 86% | 2749 fps | 100% |
| ADI AR 2213 | <<locked>> | 92% | 62,091 psi | 89% | 2825 fps | 100% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 60,234 psi | 87% | 2799 fps | 100% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 52,112 psi | 75% | 2812 fps | 99.1% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 54,331 psi | 78% | 2766 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 84% | 59,988 psi | 86% | 2723 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 90% | 62,903 psi | 90% | 2789 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 92% | 62,120 psi | 89% | 2812 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 92% | 59,799 psi | 86% | 2710 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 96% | 60,060 psi | 86% | 2785 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 88% | 60,959 psi | 88% | 2808 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 57,580 psi | 83% | 2851 fps | 99.5% |
| Alliant Reloder-50ᴾ | <<locked>> | 100% | 48,530 psi | 70% | 2713 fps | 97.9% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 62,279 psi | 89% | 2792 fps | 99.8% |
| Bofors RP15 | <<locked>> | 94% | 61,206 psi | 88% | 2802 fps | 100% |
| Bofors RP30 | <<locked>> | 98% | 59,683 psi | 86% | 2812 fps | 100% |
| Bofors RP5 | <<locked>> | 92% | 62,120 psi | 89% | 2812 fps | 100% |
| Bofors RP7 | <<locked>> | 82% | 59,524 psi | 86% | 2671 fps | 100% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 62,047 psi | 89% | 2818 fps | 100% |
| Hodgdon H4350 | <<locked>> | 84% | 60,901 psi | 87% | 2723 fps | 100% |
| Hodgdon H4831 | <<locked>> | 94% | 60,611 psi | 87% | 2753 fps | 100% |
| Hodgdon H4831 SC | <<locked>> | 90% | 59,828 psi | 86% | 2743 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 59,901 psi | 86% | 2644 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 96% | 59,292 psi | 85% | 2881 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 61,293 psi | 88% | 2776 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,666 psi | 54% | 1663 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 62,453 psi | 90% | 2684 fps | 100% |
| IMR 4350 | <<locked>> | 86% | 62,033 psi | 89% | 2713 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 82% | 61,148 psi | 88% | 2690 fps | 100% |
| IMR 4831 | <<locked>> | 88% | 60,365 psi | 87% | 2684 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 61,293 psi | 88% | 2733 fps | 100% |
| IMR 7828 SSC | <<locked>> | 90% | 60,249 psi | 87% | 2808 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 96% | 59,640 psi | 86% | 2690 fps | 97.3% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 49,777 psi | 72% | 2700 fps | 100% |
| Lovex D100ᴾ | <<locked>> | 100% | 59,727 psi | 86% | 2736 fps | 96.4% |
| Lovex S065 | <<locked>> | 84% | 62,047 psi | 89% | 2684 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 60,394 psi | 87% | 2690 fps | 100% |
| Lovex S071 | <<locked>> | 96% | 59,263 psi | 85% | 2677 fps | 100% |
| Norma 204 | <<locked>> | 84% | 59,640 psi | 86% | 2730 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 50,546 psi | 73% | 2717 fps | 100% |
| Norma MRP | <<locked>> | 90% | 62,453 psi | 90% | 2828 fps | 100% |
| Norma URP | <<locked>> | 84% | 60,524 psi | 87% | 2703 fps | 100% |
| Ramshot Grand | <<locked>> | 88% | 60,655 psi | 87% | 2815 fps | 100% |
| Ramshot Hunter | <<locked>> | 84% | 59,451 psi | 85% | 2720 fps | 100% |
| Ramshot Magnum | <<locked>> | 92% | 61,946 psi | 89% | 2785 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,508 psi | 55% | 1703 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 62,917 psi | 90% | 2746 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 84% | 61,815 psi | 89% | 2779 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 60,278 psi | 87% | 2874 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 59,132 psi | 85% | 2851 fps | 100% |
| Rottweil R 904 | <<locked>> | 88% | 60,133 psi | 86% | 2717 fps | 100% |
| Rottweil R 905 | <<locked>> | 90% | 62,729 psi | 90% | 2779 fps | 100% |
| Rottweil R 907 | <<locked>> | 82% | 59,524 psi | 86% | 2671 fps | 100% |
| Shooters World 50 BMGᴾ | <<locked>> | 100% | 59,727 psi | 86% | 2736 fps | 96.4% |
| Shooters World Long Rifle | <<locked>> | 84% | 62,047 psi | 89% | 2684 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 60,510 psi | 87% | 2690 fps | 100% |
| SNPE Vectan SP 13ᴾ | <<locked>> | 100% | 42,859 psi | 62% | 2536 fps | 95.9% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 60,974 psi | 88% | 2644 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 62,410 psi | 90% | 2779 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 61,670 psi | 89% | 2717 fps | 100% |
| Somchem S365 | <<locked>> | 86% | 62,120 psi | 89% | 2700 fps | 100% |
| Somchem S385 | <<locked>> | 90% | 62,903 psi | 90% | 2743 fps | 100% |
| Unknown powder | <<locked>> | 82% | 60,495 psi | 87% | 2703 fps | 100% |
| Vihtavuori N150 | <<locked>> | 86% | 62,975 psi | 90% | 2625 fps | 100% |
| Vihtavuori N160 | <<locked>> | 82% | 60,698 psi | 87% | 2671 fps | 100% |
| Vihtavuori N165 | <<locked>> | 94% | 60,901 psi | 87% | 2710 fps | 100% |
| Vihtavuori N170ᴾ | <<locked>> | 100% | 55,347 psi | 80% | 2690 fps | 98% |
| Vihtavuori N550 | <<locked>> | 82% | 61,279 psi | 88% | 2717 fps | 100% |
| Vihtavuori N555 | <<locked>> | 90% | 61,714 psi | 89% | 2733 fps | 100% |
| Vihtavuori N560 | <<locked>> | 92% | 62,627 psi | 90% | 2854 fps | 100% |
| Vihtavuori N565 | <<locked>> | 96% | 62,279 psi | 89% | 2828 fps | 100% |
| Vihtavuori N568 | <<locked>> | 98% | 59,669 psi | 86% | 2848 fps | 100% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 61,641 psi | 89% | 2917 fps | 99.7% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 61,743 psi | 89% | 2644 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 92% | 59,973 psi | 86% | 2805 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 88% | 60,582 psi | 87% | 2720 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% | 41,249 psi | 59% | 2421 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 54,723 psi | 79% | 2625 fps | 100% |
| Accurate MAGPRO | <<locked>> | 80% | 40,538 psi | 58% | 2503 fps | 97.4% |
| ADI APS 450 | <<locked>> | 80% | 59,393 psi | 85% | 2047 fps | 100% |
| ADI AR 2209 | <<locked>> | 80% | 45,614 psi | 66% | 2546 fps | 99.9% |
| ADI AR 2213 | <<locked>> | 80% | 40,785 psi | 59% | 2497 fps | 98.9% |
| ADI AR 2217 | <<locked>> | 80% | 30,269 psi | 43% | 2264 fps | 95.9% |
| ADI AR 2218 | <<locked>> | 92% | 39,030 psi | 56% | 2549 fps | 95.4% |
| ADI AR 2225 | <<locked>> | 80% | 27,514 psi | 40% | 2238 fps | 97.9% |
| Alliant Reloder-16 | <<locked>> | 80% | 52,562 psi | 76% | 2628 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 45,585 psi | 65% | 2539 fps | 99.9% |
| Alliant Reloder-22 | <<locked>> | 80% | 41,379 psi | 59% | 2500 fps | 99.6% |
| Alliant Reloder-23 | <<locked>> | 80% | 40,248 psi | 58% | 2438 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 34,621 psi | 50% | 2392 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 80% | 45,295 psi | 65% | 2595 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 90% | 39,479 psi | 57% | 2543 fps | 96% |
| Alliant Reloder-50 | <<locked>> | 94% | 38,609 psi | 55% | 2526 fps | 95.1% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 39,842 psi | 57% | 2425 fps | 96% |
| Bofors RP15 | <<locked>> | 80% | 38,580 psi | 55% | 2444 fps | 99.2% |
| Bofors RP30 | <<locked>> | 80% | 32,111 psi | 46% | 2333 fps | 97.1% |
| Bofors RP5 | <<locked>> | 80% | 41,379 psi | 59% | 2500 fps | 99.6% |
| Bofors RP7 | <<locked>> | 80% | 56,057 psi | 81% | 2625 fps | 100% |
| Hodgdon H1000 | <<locked>> | 80% | 31,067 psi | 45% | 2287 fps | 97% |
| Hodgdon H4350 | <<locked>> | 80% | 53,708 psi | 77% | 2625 fps | 100% |
| Hodgdon H4831 | <<locked>> | 80% | 38,406 psi | 55% | 2398 fps | 97.8% |
| Hodgdon H4831 SC | <<locked>> | 80% | 42,612 psi | 61% | 2480 fps | 98.7% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 49,342 psi | 71% | 2513 fps | 100% |
| Hodgdon Retumbo | 81.8 gr | 80% | 33,837 psi | 49% | 2438 fps | 99.1% |
| Hodgdon Superformance | <<locked>> | 80% | 56,913 psi | 82% | 2720 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,195 psi | 41% | 1486 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 58,711 psi | 84% | 2638 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 51,300 psi | 74% | 2572 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 80% | 57,305 psi | 82% | 2641 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 46,934 psi | 67% | 2503 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 44,701 psi | 64% | 2487 fps | 99.1% |
| IMR 7828 SSC | <<locked>> | 80% | 42,250 psi | 61% | 2533 fps | 99.2% |
| IMR 7977 Enduron | <<locked>> | 90% | 49,197 psi | 71% | 2533 fps | 95.1% |
| IMR 8133 Enduron | <<locked>> | 84% | 28,703 psi | 41% | 2267 fps | 95.3% |
| Lovex D100 | <<locked>> | 98% | 55,506 psi | 80% | 2680 fps | 95.5% |
| Lovex S065 | <<locked>> | 80% | 54,839 psi | 79% | 2592 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 53,287 psi | 77% | 2595 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 35,389 psi | 51% | 2310 fps | 99.8% |
| Norma 204 | <<locked>> | 80% | 52,098 psi | 75% | 2628 fps | 100% |
| Norma 217 | <<locked>> | 80% | 24,990 psi | 36% | 2178 fps | 95.7% |
| Norma MRP | <<locked>> | 80% | 43,888 psi | 63% | 2566 fps | 100% |
| Norma URP | <<locked>> | 80% | 53,214 psi | 76% | 2612 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 44,382 psi | 64% | 2585 fps | 99.7% |
| Ramshot Hunter | <<locked>> | 80% | 52,069 psi | 75% | 2621 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 38,827 psi | 56% | 2451 fps | 99.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,863 psi | 41% | 1519 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 54,810 psi | 79% | 2648 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 53,592 psi | 77% | 2680 fps | 100% |
| ReloadSwiss RS 76 | 87.5 gr | 80% | 32,779 psi | 47% | 2411 fps | 99.5% |
| ReloadSwiss RS 80 | <<locked>> | 82% | 32,068 psi | 46% | 2369 fps | 95.4% |
| Rottweil R 904 | <<locked>> | 80% | 46,514 psi | 67% | 2520 fps | 99.6% |
| Rottweil R 905 | <<locked>> | 80% | 45,005 psi | 65% | 2526 fps | 99.9% |
| Rottweil R 907 | <<locked>> | 80% | 56,057 psi | 81% | 2625 fps | 100% |
| Shooters World 50 BMG | <<locked>> | 98% | 55,506 psi | 80% | 2680 fps | 95.5% |
| Shooters World Long Rifle | <<locked>> | 80% | 54,839 psi | 79% | 2592 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 53,229 psi | 76% | 2595 fps | 100% |
| SNPE Vectan SP 13 | <<locked>> | 98% | 39,929 psi | 57% | 2480 fps | 95% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 53,534 psi | 77% | 2549 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 44,759 psi | 64% | 2526 fps | 99.9% |
| Somchem S361 | <<locked>> | 80% | 47,355 psi | 68% | 2513 fps | 99.3% |
| Somchem S365 | <<locked>> | 80% | 50,792 psi | 73% | 2566 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 45,324 psi | 65% | 2503 fps | 100% |
| Unknown powder | <<locked>> | 80% | 56,739 psi | 82% | 2657 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 52,533 psi | 75% | 2500 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 56,797 psi | 82% | 2621 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 38,479 psi | 55% | 2375 fps | 99.5% |
| Vihtavuori N170 | <<locked>> | 92% | 42,699 psi | 61% | 2480 fps | 95.1% |
| Vihtavuori N550 | <<locked>> | 80% | 57,377 psi | 82% | 2667 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 44,701 psi | 64% | 2503 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 41,553 psi | 60% | 2526 fps | 98.7% |
| Vihtavuori N565 | <<locked>> | 80% | 36,013 psi | 52% | 2398 fps | 97.6% |
| Vihtavuori N568 | <<locked>> | 82% | 33,547 psi | 48% | 2388 fps | 95.4% |
| Vihtavuori N570 | 94.4 gr | 88% | 39,842 psi | 57% | 2559 fps | 95.7% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 53,809 psi | 77% | 2552 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 37,942 psi | 55% | 2497 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 45,527 psi | 65% | 2510 fps | 99.9% |
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 86 powders for .338 Lapua Mag. Ackley Improved loaded with the .338 | 280gr | Barnes LRX BT. Vihtavuori N570 delivers the highest muzzle velocity at 2,917 fps; across all powders the maximum-charge window runs from 1,663 fps to 2,917 fps. Accurate 8700 gives the best case fill at 100 %, and 86 of the 86 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 280.0 gr projectile in 0.338" calls for a 1:10.5 twist; slower twists will usually not stabilise this weight. Accurate 8700, ADI AR 2217, ADI AR 2218 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. Hodgdon Retumbo, ReloadSwiss RS 76, Vihtavuori N570 rank at the top here: for .338 Lapua Mag. Ackley Improved with the .338 | 280gr | Barnes LRX BT they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Hodgdon 50BMG, Hodgdon US 869, Ramshot LRT 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.