Load Specifications
Load data in caliber .338 Lapua Mag. Ackley Improved with .338 | 285gr | Barnes TAC-X 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>> | 90% | 59,132 psi | 85% | 2654 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 59,770 psi | 86% | 2664 fps | 100% |
| Accurate 8700ᴾ | <<locked>> | 100% | 42,119 psi | 61% | 2526 fps | 96.3% |
| Accurate MAGPRO | <<locked>> | 90% | 59,219 psi | 85% | 2789 fps | 100% |
| ADI APS 450 | <<locked>> | 82% | 61,395 psi | 88% | 2060 fps | 100% |
| ADI AR 2209 | <<locked>> | 88% | 60,843 psi | 87% | 2743 fps | 100% |
| ADI AR 2213 | <<locked>> | 90% | 59,306 psi | 85% | 2769 fps | 100% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 61,757 psi | 89% | 2795 fps | 100% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 53,577 psi | 77% | 2815 fps | 99.4% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 56,057 psi | 81% | 2766 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 84% | 61,250 psi | 88% | 2717 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 60,191 psi | 86% | 2733 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 90% | 59,480 psi | 85% | 2756 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 92% | 61,293 psi | 88% | 2703 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 96% | 61,627 psi | 89% | 2782 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 88% | 62,613 psi | 90% | 2802 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 59,335 psi | 85% | 2854 fps | 99.7% |
| Alliant Reloder-50ᴾ | <<locked>> | 100% | 50,183 psi | 72% | 2720 fps | 98.4% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 59,495 psi | 85% | 2736 fps | 99.7% |
| Bofors RP15 | <<locked>> | 94% | 62,453 psi | 90% | 2795 fps | 100% |
| Bofors RP30 | <<locked>> | 98% | 61,192 psi | 88% | 2808 fps | 100% |
| Bofors RP5 | <<locked>> | 90% | 59,480 psi | 85% | 2756 fps | 100% |
| Bofors RP7 | <<locked>> | 82% | 60,597 psi | 87% | 2664 fps | 100% |
| Hodgdon H1000 | <<locked>> | 98% | 59,335 psi | 85% | 2762 fps | 100% |
| Hodgdon H4350 | <<locked>> | 84% | 62,018 psi | 89% | 2717 fps | 100% |
| Hodgdon H4831 | <<locked>> | 94% | 61,757 psi | 89% | 2749 fps | 100% |
| Hodgdon H4831 SC | <<locked>> | 90% | 61,177 psi | 88% | 2740 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 61,105 psi | 88% | 2635 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 96% | 60,785 psi | 87% | 2874 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 62,540 psi | 90% | 2769 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,666 psi | 54% | 1654 fps | 100% |
| IMR 4350 | <<locked>> | 84% | 59,393 psi | 85% | 2661 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 82% | 62,091 psi | 89% | 2680 fps | 100% |
| IMR 4831 | <<locked>> | 88% | 61,540 psi | 88% | 2674 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 62,410 psi | 90% | 2726 fps | 100% |
| IMR 7828 SSC | <<locked>> | 90% | 61,786 psi | 89% | 2805 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 96% | 60,742 psi | 87% | 2687 fps | 97.7% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 51,213 psi | 74% | 2700 fps | 100% |
| Lovex D100ᴾ | <<locked>> | 100% | 61,235 psi | 88% | 2740 fps | 96.9% |
| Lovex S065 | <<locked>> | 82% | 59,205 psi | 85% | 2628 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 61,496 psi | 88% | 2680 fps | 100% |
| Lovex S071 | <<locked>> | 96% | 60,655 psi | 87% | 2674 fps | 100% |
| Norma 204 | <<locked>> | 84% | 60,785 psi | 87% | 2723 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 52,025 psi | 75% | 2713 fps | 100% |
| Norma MRP | <<locked>> | 88% | 59,582 psi | 86% | 2772 fps | 100% |
| Norma URP | <<locked>> | 84% | 61,714 psi | 89% | 2694 fps | 100% |
| Ramshot Grand | <<locked>> | 88% | 62,308 psi | 90% | 2815 fps | 100% |
| Ramshot Hunter | <<locked>> | 84% | 60,626 psi | 87% | 2713 fps | 100% |
| Ramshot Magnum | <<locked>> | 90% | 58,842 psi | 85% | 2726 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,667 psi | 56% | 1693 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 60,046 psi | 86% | 2690 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 82% | 58,755 psi | 84% | 2720 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 62,047 psi | 89% | 2871 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 60,959 psi | 88% | 2854 fps | 100% |
| Rottweil R 904 | <<locked>> | 88% | 61,221 psi | 88% | 2710 fps | 100% |
| Rottweil R 905 | <<locked>> | 88% | 59,988 psi | 86% | 2723 fps | 100% |
| Rottweil R 907 | <<locked>> | 82% | 60,597 psi | 87% | 2664 fps | 100% |
| Shooters World 50 BMGᴾ | <<locked>> | 100% | 61,235 psi | 88% | 2740 fps | 96.9% |
| Shooters World Long Rifle | <<locked>> | 82% | 59,205 psi | 85% | 2628 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 61,496 psi | 88% | 2680 fps | 100% |
| SNPE Vectan SP 13ᴾ | <<locked>> | 100% | 44,034 psi | 63% | 2539 fps | 96.5% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 62,076 psi | 89% | 2638 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 59,582 psi | 86% | 2720 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 62,917 psi | 90% | 2710 fps | 100% |
| Somchem S365 | <<locked>> | 84% | 59,466 psi | 85% | 2648 fps | 100% |
| Somchem S385 | <<locked>> | 88% | 60,220 psi | 87% | 2690 fps | 100% |
| Unknown powder | <<locked>> | 82% | 61,685 psi | 89% | 2697 fps | 100% |
| Vihtavuori N150 | <<locked>> | 84% | 60,408 psi | 87% | 2575 fps | 100% |
| Vihtavuori N160 | <<locked>> | 82% | 61,859 psi | 89% | 2661 fps | 100% |
| Vihtavuori N165 | <<locked>> | 94% | 62,062 psi | 89% | 2703 fps | 100% |
| Vihtavuori N170ᴾ | <<locked>> | 100% | 56,579 psi | 81% | 2690 fps | 98.4% |
| Vihtavuori N550 | <<locked>> | 82% | 62,439 psi | 90% | 2707 fps | 100% |
| Vihtavuori N555 | <<locked>> | 88% | 59,292 psi | 85% | 2684 fps | 100% |
| Vihtavuori N560 | <<locked>> | 90% | 59,973 psi | 86% | 2799 fps | 100% |
| Vihtavuori N565 | <<locked>> | 94% | 59,596 psi | 86% | 2772 fps | 100% |
| Vihtavuori N568 | <<locked>> | 98% | 61,409 psi | 88% | 2851 fps | 100% |
| Vihtavuori N570 | <<locked>> | 98% | 58,943 psi | 85% | 2861 fps | 99.6% |
| Winchester 6.5 StaBALL | <<locked>> | 82% | 58,914 psi | 85% | 2592 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 92% | 61,815 psi | 89% | 2799 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 88% | 61,728 psi | 89% | 2713 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% | 42,105 psi | 60% | 2418 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 55,753 psi | 80% | 2615 fps | 100% |
| Accurate 8700 | <<locked>> | 98% | 39,088 psi | 56% | 2467 fps | 95.3% |
| Accurate MAGPRO | <<locked>> | 80% | 41,539 psi | 60% | 2503 fps | 97.9% |
| ADI APS 450 | <<locked>> | 80% | 59,321 psi | 85% | 2034 fps | 100% |
| ADI AR 2209 | <<locked>> | 80% | 46,659 psi | 67% | 2543 fps | 100% |
| ADI AR 2213 | <<locked>> | 80% | 41,785 psi | 60% | 2497 fps | 99.2% |
| ADI AR 2217 | <<locked>> | 80% | 30,908 psi | 44% | 2264 fps | 96.6% |
| ADI AR 2218 | <<locked>> | 90% | 37,231 psi | 53% | 2490 fps | 95% |
| ADI AR 2225 | <<locked>> | 80% | 28,239 psi | 41% | 2241 fps | 98.4% |
| Alliant Reloder-16 | <<locked>> | 80% | 53,751 psi | 77% | 2621 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 46,441 psi | 67% | 2533 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 80% | 42,395 psi | 61% | 2500 fps | 99.8% |
| Alliant Reloder-23 | <<locked>> | 80% | 41,147 psi | 59% | 2431 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 35,549 psi | 51% | 2392 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 80% | 46,499 psi | 67% | 2592 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 88% | 37,753 psi | 54% | 2490 fps | 95.7% |
| Alliant Reloder-50 | <<locked>> | 94% | 39,885 psi | 57% | 2533 fps | 95.9% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 40,567 psi | 58% | 2421 fps | 96.6% |
| Bofors RP15 | <<locked>> | 80% | 39,407 psi | 57% | 2441 fps | 99.4% |
| Bofors RP30 | <<locked>> | 80% | 32,924 psi | 47% | 2333 fps | 97.6% |
| Bofors RP5 | <<locked>> | 80% | 42,395 psi | 61% | 2500 fps | 99.8% |
| Bofors RP7 | <<locked>> | 80% | 56,898 psi | 82% | 2615 fps | 100% |
| Hodgdon H1000 | <<locked>> | 80% | 31,749 psi | 46% | 2287 fps | 97.5% |
| Hodgdon H4350 | <<locked>> | 80% | 54,592 psi | 78% | 2618 fps | 100% |
| Hodgdon H4831 | <<locked>> | 80% | 39,160 psi | 56% | 2395 fps | 98.2% |
| Hodgdon H4831 SC | <<locked>> | 80% | 43,569 psi | 63% | 2480 fps | 99% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 50,430 psi | 72% | 2507 fps | 100% |
| Hodgdon Retumbo | 82.4 gr | 80% | 34,722 psi | 50% | 2441 fps | 99.4% |
| Hodgdon Superformance | <<locked>> | 80% | 58,088 psi | 83% | 2713 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,268 psi | 41% | 1476 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 52,301 psi | 75% | 2566 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 80% | 58,218 psi | 84% | 2631 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 47,979 psi | 69% | 2497 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 45,469 psi | 65% | 2480 fps | 99.4% |
| IMR 7828 SSC | <<locked>> | 80% | 43,308 psi | 62% | 2533 fps | 99.5% |
| IMR 7977 Enduron | <<locked>> | 90% | 50,183 psi | 72% | 2533 fps | 95.6% |
| IMR 8133 Enduron | <<locked>> | 84% | 29,530 psi | 42% | 2274 fps | 96.1% |
| Lovex D100 | <<locked>> | 96% | 52,939 psi | 76% | 2625 fps | 95.2% |
| Lovex S065 | <<locked>> | 80% | 55,666 psi | 80% | 2582 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 54,172 psi | 78% | 2589 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 36,303 psi | 52% | 2310 fps | 100% |
| Norma 204 | <<locked>> | 80% | 53,127 psi | 76% | 2621 fps | 100% |
| Norma 217 | <<locked>> | 80% | 25,759 psi | 37% | 2185 fps | 96.5% |
| Norma MRP | <<locked>> | 80% | 45,005 psi | 65% | 2562 fps | 100% |
| Norma URP | <<locked>> | 80% | 54,172 psi | 78% | 2602 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 45,745 psi | 66% | 2585 fps | 99.9% |
| Ramshot Hunter | <<locked>> | 80% | 53,156 psi | 76% | 2618 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 39,856 psi | 57% | 2451 fps | 99.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,950 psi | 42% | 1512 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 55,999 psi | 80% | 2641 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 54,810 psi | 79% | 2671 fps | 100% |
| ReloadSwiss RS 76 | 88.2 gr | 80% | 33,765 psi | 49% | 2418 fps | 99.8% |
| ReloadSwiss RS 80 | <<locked>> | 80% | 30,603 psi | 44% | 2313 fps | 95% |
| Rottweil R 904 | <<locked>> | 80% | 47,485 psi | 68% | 2516 fps | 99.8% |
| Rottweil R 905 | <<locked>> | 80% | 46,035 psi | 66% | 2523 fps | 100% |
| Rottweil R 907 | <<locked>> | 80% | 56,898 psi | 82% | 2615 fps | 100% |
| Shooters World 50 BMG | <<locked>> | 96% | 52,939 psi | 76% | 2625 fps | 95.2% |
| Shooters World Long Rifle | <<locked>> | 80% | 55,666 psi | 80% | 2582 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 54,172 psi | 78% | 2589 fps | 100% |
| SNPE Vectan SP 13 | <<locked>> | 98% | 41,060 psi | 59% | 2487 fps | 95.6% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 54,563 psi | 78% | 2543 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 45,701 psi | 66% | 2523 fps | 100% |
| Somchem S361 | <<locked>> | 80% | 48,254 psi | 69% | 2510 fps | 99.6% |
| Somchem S365 | <<locked>> | 80% | 51,996 psi | 75% | 2559 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 46,311 psi | 67% | 2500 fps | 100% |
| Unknown powder | <<locked>> | 80% | 57,711 psi | 83% | 2648 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 53,403 psi | 77% | 2490 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 57,928 psi | 83% | 2615 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 39,247 psi | 56% | 2372 fps | 99.7% |
| Vihtavuori N170 | <<locked>> | 92% | 43,772 psi | 63% | 2487 fps | 95.7% |
| Vihtavuori N550 | <<locked>> | 80% | 58,508 psi | 84% | 2661 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 45,614 psi | 66% | 2497 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 42,598 psi | 61% | 2526 fps | 99% |
| Vihtavuori N565 | <<locked>> | 80% | 36,941 psi | 53% | 2402 fps | 98% |
| Vihtavuori N568 | <<locked>> | 80% | 31,995 psi | 46% | 2333 fps | 95% |
| Vihtavuori N570 | 92.9 gr | 86% | 38,087 psi | 55% | 2500 fps | 95.3% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 55,042 psi | 79% | 2546 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 39,189 psi | 56% | 2493 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 46,528 psi | 67% | 2507 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 85 powders for .338 Lapua Mag. Ackley Improved loaded with the .338 | 285gr | Barnes TAC-X. Hodgdon Retumbo delivers the highest muzzle velocity at 2,874 fps; across all powders the maximum-charge window runs from 1,654 fps to 2,874 fps. Accurate 8700 gives the best case fill at 100 %, and 85 of the 85 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 285.0 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 | 285gr | Barnes TAC-X they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Hodgdon 50BMG, Hodgdon US 869, Vihtavuori 20N29 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.