Load Specifications
Load data in caliber .338 Lapua Mag. Ackley Improved with .338 | 250gr | Nosler Partition Gold bullet and 78 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% | 59,785 psi | 86% | 2844 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 60,263 psi | 87% | 2858 fps | 100% |
| Accurate MAGPRO | <<locked>> | 90% | 59,611 psi | 86% | 2972 fps | 99.8% |
| ADI APS 450 | <<locked>> | 82% | 61,366 psi | 88% | 2228 fps | 100% |
| ADI AR 2209 | <<locked>> | 88% | 61,061 psi | 88% | 2933 fps | 100% |
| ADI AR 2213 | <<locked>> | 90% | 59,524 psi | 86% | 2956 fps | 100% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 62,062 psi | 89% | 2986 fps | 100% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 54,201 psi | 78% | 2995 fps | 98.9% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 56,405 psi | 81% | 2949 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 84% | 61,366 psi | 88% | 2910 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 60,394 psi | 87% | 2920 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 90% | 59,857 psi | 86% | 2946 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 92% | 61,598 psi | 88% | 2894 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 96% | 62,004 psi | 89% | 2972 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 86% | 58,624 psi | 84% | 2940 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 59,959 psi | 86% | 3038 fps | 99.4% |
| Alliant Reloder-50ᴾ | <<locked>> | 100% | 51,140 psi | 73% | 2897 fps | 97.8% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 59,799 psi | 86% | 2917 fps | 99.3% |
| Bofors RP15 | <<locked>> | 94% | 62,859 psi | 90% | 2989 fps | 100% |
| Bofors RP30 | <<locked>> | 98% | 61,670 psi | 89% | 2999 fps | 100% |
| Bofors RP5 | <<locked>> | 90% | 59,857 psi | 86% | 2946 fps | 100% |
| Bofors RP7 | <<locked>> | 82% | 60,916 psi | 88% | 2854 fps | 100% |
| Hodgdon H1000 | <<locked>> | 98% | 59,582 psi | 86% | 2949 fps | 100% |
| Hodgdon H4350 | <<locked>> | 84% | 62,120 psi | 89% | 2907 fps | 100% |
| Hodgdon H4831 | <<locked>> | 94% | 62,178 psi | 89% | 2936 fps | 100% |
| Hodgdon H4831 SC | <<locked>> | 90% | 61,424 psi | 88% | 2930 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 61,337 psi | 88% | 2825 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 96% | 61,076 psi | 88% | 3071 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 62,874 psi | 90% | 2959 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,710 psi | 54% | 1791 fps | 100% |
| IMR 4350 | <<locked>> | 84% | 59,495 psi | 85% | 2848 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 82% | 62,178 psi | 89% | 2871 fps | 100% |
| IMR 4831 | <<locked>> | 88% | 61,902 psi | 89% | 2864 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 62,526 psi | 90% | 2913 fps | 100% |
| IMR 7828 SSC | <<locked>> | 90% | 61,975 psi | 89% | 2995 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 96% | 61,076 psi | 88% | 2864 fps | 96.9% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 51,779 psi | 74% | 2877 fps | 99.9% |
| Lovex D100ᴾ | <<locked>> | 100% | 61,844 psi | 89% | 2917 fps | 96.1% |
| Lovex S065 | <<locked>> | 82% | 59,625 psi | 86% | 2818 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 61,859 psi | 89% | 2874 fps | 100% |
| Lovex S071 | <<locked>> | 96% | 61,206 psi | 88% | 2861 fps | 100% |
| Norma 204 | <<locked>> | 84% | 60,974 psi | 88% | 2913 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 52,750 psi | 76% | 2897 fps | 100% |
| Norma MRP | <<locked>> | 88% | 60,046 psi | 86% | 2963 fps | 100% |
| Norma URP | <<locked>> | 84% | 61,975 psi | 89% | 2887 fps | 100% |
| Ramshot Grand | <<locked>> | 88% | 62,569 psi | 90% | 3005 fps | 100% |
| Ramshot Hunter | <<locked>> | 84% | 60,858 psi | 87% | 2904 fps | 100% |
| Ramshot Magnum | <<locked>> | 90% | 59,321 psi | 85% | 2913 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,653 psi | 56% | 1834 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 60,394 psi | 87% | 2881 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 82% | 59,045 psi | 85% | 2913 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 62,540 psi | 90% | 3064 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 61,540 psi | 88% | 3038 fps | 100% |
| Rottweil R 904 | <<locked>> | 88% | 61,569 psi | 88% | 2904 fps | 100% |
| Rottweil R 905 | <<locked>> | 88% | 60,307 psi | 87% | 2913 fps | 100% |
| Rottweil R 907 | <<locked>> | 82% | 60,916 psi | 88% | 2854 fps | 100% |
| Shooters World 50 BMGᴾ | <<locked>> | 100% | 61,844 psi | 89% | 2917 fps | 96.1% |
| Shooters World Long Rifle | <<locked>> | 82% | 59,625 psi | 86% | 2818 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 61,859 psi | 89% | 2874 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 62,395 psi | 90% | 2825 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 59,944 psi | 86% | 2910 fps | 100% |
| Somchem S361 | <<locked>> | 86% | 59,277 psi | 85% | 2844 fps | 99.9% |
| Somchem S365 | <<locked>> | 84% | 59,727 psi | 86% | 2838 fps | 100% |
| Somchem S385 | <<locked>> | 88% | 60,611 psi | 87% | 2881 fps | 100% |
| Unknown powder | <<locked>> | 82% | 61,859 psi | 89% | 2890 fps | 100% |
| Vihtavuori N150 | <<locked>> | 84% | 60,597 psi | 87% | 2762 fps | 100% |
| Vihtavuori N160 | <<locked>> | 82% | 62,192 psi | 89% | 2851 fps | 100% |
| Vihtavuori N165 | <<locked>> | 94% | 62,468 psi | 90% | 2890 fps | 100% |
| Vihtavuori N170ᴾ | <<locked>> | 100% | 57,188 psi | 82% | 2867 fps | 97.7% |
| Vihtavuori N550 | <<locked>> | 82% | 62,816 psi | 90% | 2900 fps | 100% |
| Vihtavuori N555 | <<locked>> | 88% | 59,727 psi | 86% | 2874 fps | 100% |
| Vihtavuori N560 | <<locked>> | 90% | 60,176 psi | 86% | 2986 fps | 100% |
| Vihtavuori N565 | <<locked>> | 94% | 60,234 psi | 87% | 2963 fps | 100% |
| Vihtavuori N568 | <<locked>> | 98% | 61,888 psi | 89% | 3038 fps | 100% |
| Vihtavuori N570 | <<locked>> | 98% | 59,553 psi | 86% | 3045 fps | 99.1% |
| Winchester 6.5 StaBALL | <<locked>> | 82% | 59,088 psi | 85% | 2776 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 92% | 62,120 psi | 89% | 2992 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 88% | 62,178 psi | 89% | 2904 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% | 42,772 psi | 61% | 2589 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 56,260 psi | 81% | 2805 fps | 100% |
| Accurate MAGPRO | <<locked>> | 80% | 42,076 psi | 60% | 2674 fps | 97.1% |
| ADI APS 450 | <<locked>> | 80% | 59,466 psi | 85% | 2201 fps | 100% |
| ADI AR 2209 | <<locked>> | 80% | 46,905 psi | 67% | 2717 fps | 99.8% |
| ADI AR 2213 | <<locked>> | 80% | 42,090 psi | 60% | 2664 fps | 98.6% |
| ADI AR 2217 | <<locked>> | 80% | 31,459 psi | 45% | 2418 fps | 95.4% |
| ADI AR 2218 | <<locked>> | 94% | 43,497 psi | 62% | 2782 fps | 96.2% |
| ADI AR 2225 | <<locked>> | 80% | 28,761 psi | 41% | 2388 fps | 97.5% |
| Alliant Reloder-16 | <<locked>> | 80% | 53,838 psi | 77% | 2808 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 46,702 psi | 67% | 2710 fps | 99.8% |
| Alliant Reloder-22 | <<locked>> | 80% | 42,815 psi | 62% | 2671 fps | 99.5% |
| Alliant Reloder-23 | <<locked>> | 80% | 41,611 psi | 60% | 2605 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 36,013 psi | 52% | 2556 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 80% | 46,949 psi | 67% | 2772 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 90% | 41,336 psi | 59% | 2713 fps | 95.7% |
| Alliant Reloder-50 | <<locked>> | 96% | 44,063 psi | 63% | 2766 fps | 96% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 40,872 psi | 59% | 2582 fps | 95.5% |
| Bofors RP15 | <<locked>> | 80% | 39,914 psi | 57% | 2612 fps | 98.9% |
| Bofors RP30 | <<locked>> | 80% | 33,460 psi | 48% | 2490 fps | 96.6% |
| Bofors RP5 | <<locked>> | 80% | 42,815 psi | 62% | 2671 fps | 99.5% |
| Bofors RP7 | <<locked>> | 80% | 57,217 psi | 82% | 2805 fps | 100% |
| Hodgdon H1000 | <<locked>> | 80% | 32,256 psi | 46% | 2441 fps | 96.5% |
| Hodgdon H4350 | <<locked>> | 80% | 54,781 psi | 79% | 2802 fps | 100% |
| Hodgdon H4831 | <<locked>> | 80% | 39,494 psi | 57% | 2559 fps | 97.4% |
| Hodgdon H4831 SC | <<locked>> | 80% | 43,918 psi | 63% | 2648 fps | 98.4% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 50,575 psi | 73% | 2684 fps | 100% |
| Hodgdon Retumbo | 89.5 gr | 80% | 35,114 psi | 50% | 2598 fps | 98.8% |
| Hodgdon Superformance | <<locked>> | 80% | 58,421 psi | 84% | 2904 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,326 psi | 41% | 1601 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 52,562 psi | 76% | 2749 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 80% | 58,450 psi | 84% | 2822 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 48,370 psi | 69% | 2677 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 45,774 psi | 66% | 2651 fps | 98.8% |
| IMR 7828 SSC | <<locked>> | 80% | 43,569 psi | 63% | 2703 fps | 98.9% |
| IMR 7977 Enduron | <<locked>> | 92% | 53,766 psi | 77% | 2756 fps | 95.4% |
| IMR 8133 Enduron | <<locked>> | 86% | 32,169 psi | 46% | 2480 fps | 95.9% |
| Lovex D100 | <<locked>> | 98% | 57,508 psi | 83% | 2854 fps | 95.2% |
| Lovex S065 | <<locked>> | 80% | 56,072 psi | 81% | 2769 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 54,650 psi | 79% | 2776 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 36,985 psi | 53% | 2477 fps | 99.7% |
| Norma 204 | <<locked>> | 80% | 53,330 psi | 77% | 2802 fps | 100% |
| Norma 217 | <<locked>> | 80% | 26,426 psi | 38% | 2336 fps | 95.4% |
| Norma MRP | <<locked>> | 80% | 45,397 psi | 65% | 2740 fps | 100% |
| Norma URP | <<locked>> | 80% | 54,549 psi | 78% | 2789 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 45,948 psi | 66% | 2759 fps | 99.5% |
| Ramshot Hunter | <<locked>> | 80% | 53,374 psi | 77% | 2799 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 40,451 psi | 58% | 2618 fps | 99.6% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,095 psi | 42% | 1640 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 56,478 psi | 81% | 2831 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 54,940 psi | 79% | 2858 fps | 100% |
| ReloadSwiss RS 76 | 95.8 gr | 80% | 34,287 psi | 49% | 2575 fps | 99.3% |
| ReloadSwiss RS 80 | <<locked>> | 82% | 33,663 psi | 48% | 2530 fps | 95% |
| Rottweil R 904 | <<locked>> | 80% | 47,718 psi | 69% | 2690 fps | 99.4% |
| Rottweil R 905 | <<locked>> | 80% | 46,427 psi | 67% | 2700 fps | 99.8% |
| Rottweil R 907 | <<locked>> | 80% | 57,217 psi | 82% | 2805 fps | 100% |
| Shooters World 50 BMG | <<locked>> | 98% | 57,508 psi | 83% | 2854 fps | 95.2% |
| Shooters World Long Rifle | <<locked>> | 80% | 56,072 psi | 81% | 2769 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 54,650 psi | 79% | 2776 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 54,810 psi | 79% | 2726 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 46,093 psi | 66% | 2697 fps | 99.8% |
| Somchem S361 | <<locked>> | 80% | 48,515 psi | 70% | 2680 fps | 99.1% |
| Somchem S365 | <<locked>> | 80% | 52,373 psi | 75% | 2743 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 46,775 psi | 67% | 2674 fps | 100% |
| Unknown powder | <<locked>> | 80% | 57,899 psi | 83% | 2838 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 53,664 psi | 77% | 2674 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 58,233 psi | 84% | 2802 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 39,769 psi | 57% | 2536 fps | 99.3% |
| Vihtavuori N170 | <<locked>> | 94% | 47,268 psi | 68% | 2703 fps | 95.6% |
| Vihtavuori N550 | <<locked>> | 80% | 58,871 psi | 85% | 2851 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 46,209 psi | 66% | 2680 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 43,004 psi | 62% | 2697 fps | 98.4% |
| Vihtavuori N565 | <<locked>> | 80% | 37,550 psi | 54% | 2566 fps | 97.2% |
| Vihtavuori N568 | <<locked>> | 84% | 37,695 psi | 54% | 2612 fps | 96% |
| Vihtavuori N570 | 103.3 gr | 88% | 41,524 psi | 60% | 2723 fps | 95.2% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 55,201 psi | 79% | 2726 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 39,566 psi | 57% | 2667 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 46,920 psi | 67% | 2680 fps | 99.8% |
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 84 powders for .338 Lapua Mag. Ackley Improved loaded with the .338 | 250gr | Nosler Partition Gold. Hodgdon Retumbo delivers the highest muzzle velocity at 3,071 fps; across all powders the maximum-charge window runs from 1,791 fps to 3,071 fps. Accurate 8700 gives the best case fill at 100 %, and 84 of the 84 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 250.0 gr projectile in 0.338" calls for a 1:15.0 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 | 250gr | Nosler Partition Gold they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Hodgdon US 869, Ramshot LRT, 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.