Load Specifications
Load data in caliber .338 Lapua Mag. Ackley Improved with .338 | 250gr | Alaska Bullet Works Kodiak PP SPBC bullet and 76 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.
A valid access license is required to use the Personalized Load Calculator.
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% | 60,234 psi | 87% | 2851 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 60,814 psi | 87% | 2867 fps | 100% |
| Accurate MAGPRO | <<locked>> | 90% | 60,234 psi | 87% | 2982 fps | 99.8% |
| ADI APS 450 | <<locked>> | 82% | 61,366 psi | 88% | 2234 fps | 100% |
| ADI AR 2209 | <<locked>> | 88% | 61,496 psi | 88% | 2940 fps | 100% |
| ADI AR 2213 | <<locked>> | 90% | 60,002 psi | 86% | 2966 fps | 100% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 62,656 psi | 90% | 2995 fps | 100% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 54,781 psi | 79% | 3005 fps | 99% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 57,174 psi | 82% | 2963 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 84% | 61,757 psi | 89% | 2917 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 60,988 psi | 88% | 2930 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 90% | 60,278 psi | 87% | 2953 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 92% | 62,105 psi | 89% | 2900 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 96% | 62,627 psi | 90% | 2982 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 86% | 59,306 psi | 85% | 2953 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 60,800 psi | 87% | 3051 fps | 99.5% |
| Alliant Reloder-50ᴾ | <<locked>> | 100% | 51,750 psi | 74% | 2907 fps | 97.9% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 60,292 psi | 87% | 2927 fps | 99.4% |
| Bofors RP15 | <<locked>> | 92% | 59,625 psi | 86% | 2946 fps | 100% |
| Bofors RP30 | <<locked>> | 98% | 62,265 psi | 89% | 3009 fps | 100% |
| Bofors RP5 | <<locked>> | 90% | 60,278 psi | 87% | 2953 fps | 100% |
| Bofors RP7 | <<locked>> | 82% | 61,206 psi | 88% | 2861 fps | 100% |
| Hodgdon H1000 | <<locked>> | 98% | 60,220 psi | 87% | 2959 fps | 100% |
| Hodgdon H4350 | <<locked>> | 84% | 62,410 psi | 90% | 2913 fps | 100% |
| Hodgdon H4831 | <<locked>> | 94% | 62,584 psi | 90% | 2943 fps | 100% |
| Hodgdon H4831 SC | <<locked>> | 90% | 61,830 psi | 89% | 2936 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 61,844 psi | 89% | 2835 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 96% | 61,989 psi | 89% | 3081 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,710 psi | 54% | 1795 fps | 100% |
| IMR 4350 | <<locked>> | 84% | 59,944 psi | 86% | 2854 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 82% | 62,468 psi | 90% | 2877 fps | 100% |
| IMR 4831 | <<locked>> | 88% | 62,381 psi | 90% | 2874 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 88% | 59,161 psi | 85% | 2871 fps | 100% |
| IMR 7828 SSC | <<locked>> | 90% | 62,598 psi | 90% | 3005 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 96% | 61,540 psi | 88% | 2874 fps | 97% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 52,359 psi | 75% | 2887 fps | 100% |
| Lovex D100ᴾ | <<locked>> | 100% | 62,424 psi | 90% | 2927 fps | 96.3% |
| Lovex S065 | <<locked>> | 82% | 59,930 psi | 86% | 2822 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 62,323 psi | 90% | 2881 fps | 100% |
| Lovex S071 | <<locked>> | 96% | 61,830 psi | 89% | 2871 fps | 100% |
| Norma 204 | <<locked>> | 84% | 61,612 psi | 89% | 2923 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 53,374 psi | 77% | 2907 fps | 100% |
| Norma MRP | <<locked>> | 88% | 60,698 psi | 87% | 2972 fps | 100% |
| Norma URP | <<locked>> | 84% | 62,482 psi | 90% | 2894 fps | 100% |
| Ramshot Grand | <<locked>> | 86% | 58,595 psi | 84% | 2956 fps | 100% |
| Ramshot Hunter | <<locked>> | 84% | 61,511 psi | 88% | 2910 fps | 100% |
| Ramshot Magnum | <<locked>> | 90% | 59,901 psi | 86% | 2923 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,769 psi | 56% | 1841 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 61,032 psi | 88% | 2890 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 82% | 59,698 psi | 86% | 2923 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 94% | 58,566 psi | 84% | 3015 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 62,294 psi | 89% | 3048 fps | 100% |
| Rottweil R 904 | <<locked>> | 88% | 62,033 psi | 89% | 2910 fps | 100% |
| Rottweil R 905 | <<locked>> | 88% | 60,800 psi | 87% | 2923 fps | 100% |
| Rottweil R 907 | <<locked>> | 82% | 61,206 psi | 88% | 2861 fps | 100% |
| Shooters World 50 BMGᴾ | <<locked>> | 100% | 62,424 psi | 90% | 2927 fps | 96.3% |
| Shooters World Long Rifle | <<locked>> | 82% | 59,930 psi | 86% | 2822 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 62,323 psi | 90% | 2881 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 62,801 psi | 90% | 2831 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 60,379 psi | 87% | 2920 fps | 100% |
| Somchem S361 | <<locked>> | 86% | 59,625 psi | 86% | 2851 fps | 100% |
| Somchem S365 | <<locked>> | 84% | 60,263 psi | 87% | 2848 fps | 100% |
| Somchem S385 | <<locked>> | 88% | 61,192 psi | 88% | 2890 fps | 100% |
| Unknown powder | <<locked>> | 82% | 62,366 psi | 90% | 2897 fps | 100% |
| Vihtavuori N150 | <<locked>> | 84% | 61,076 psi | 88% | 2769 fps | 100% |
| Vihtavuori N160 | <<locked>> | 82% | 62,685 psi | 90% | 2861 fps | 100% |
| Vihtavuori N165 | <<locked>> | 92% | 59,176 psi | 85% | 2851 fps | 100% |
| Vihtavuori N170ᴾ | <<locked>> | 100% | 57,682 psi | 83% | 2877 fps | 97.9% |
| Vihtavuori N555 | <<locked>> | 88% | 60,379 psi | 87% | 2881 fps | 100% |
| Vihtavuori N560 | <<locked>> | 90% | 60,742 psi | 87% | 2995 fps | 100% |
| Vihtavuori N565 | <<locked>> | 94% | 60,785 psi | 87% | 2972 fps | 100% |
| Vihtavuori N568 | <<locked>> | 98% | 62,642 psi | 90% | 3048 fps | 100% |
| Vihtavuori N570 | <<locked>> | 98% | 60,292 psi | 87% | 3058 fps | 99.2% |
| Winchester 6.5 StaBALL | <<locked>> | 82% | 59,698 psi | 86% | 2782 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 92% | 62,888 psi | 90% | 3002 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 88% | 62,758 psi | 90% | 2910 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% | 43,221 psi | 62% | 2598 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 56,782 psi | 82% | 2815 fps | 100% |
| Accurate MAGPRO | <<locked>> | 80% | 42,467 psi | 61% | 2680 fps | 97.2% |
| ADI APS 450 | <<locked>> | 80% | 59,480 psi | 85% | 2205 fps | 100% |
| ADI AR 2209 | <<locked>> | 80% | 47,224 psi | 68% | 2726 fps | 99.8% |
| ADI AR 2213 | <<locked>> | 80% | 42,496 psi | 61% | 2674 fps | 98.7% |
| ADI AR 2217 | <<locked>> | 80% | 31,676 psi | 46% | 2425 fps | 95.6% |
| ADI AR 2218 | <<locked>> | 92% | 40,988 psi | 59% | 2726 fps | 95.2% |
| ADI AR 2225 | <<locked>> | 80% | 29,066 psi | 42% | 2402 fps | 97.7% |
| Alliant Reloder-16 | <<locked>> | 80% | 54,404 psi | 78% | 2818 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 47,137 psi | 68% | 2717 fps | 99.8% |
| Alliant Reloder-22 | <<locked>> | 80% | 43,279 psi | 62% | 2680 fps | 99.5% |
| Alliant Reloder-23 | <<locked>> | 80% | 42,076 psi | 60% | 2615 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 36,318 psi | 52% | 2562 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 80% | 47,442 psi | 68% | 2779 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 90% | 41,814 psi | 60% | 2726 fps | 95.9% |
| Alliant Reloder-50 | <<locked>> | 94% | 41,350 psi | 59% | 2713 fps | 95.1% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 41,162 psi | 59% | 2592 fps | 95.7% |
| Bofors RP15 | <<locked>> | 80% | 40,234 psi | 58% | 2618 fps | 99% |
| Bofors RP30 | <<locked>> | 80% | 33,866 psi | 49% | 2500 fps | 96.8% |
| Bofors RP5 | <<locked>> | 80% | 43,279 psi | 62% | 2680 fps | 99.5% |
| Bofors RP7 | <<locked>> | 80% | 57,537 psi | 83% | 2812 fps | 100% |
| Hodgdon H1000 | <<locked>> | 80% | 32,518 psi | 47% | 2448 fps | 96.7% |
| Hodgdon H4350 | <<locked>> | 80% | 55,288 psi | 79% | 2812 fps | 100% |
| Hodgdon H4831 | <<locked>> | 80% | 39,900 psi | 57% | 2566 fps | 97.5% |
| Hodgdon H4831 SC | <<locked>> | 80% | 44,309 psi | 64% | 2657 fps | 98.5% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 51,082 psi | 73% | 2694 fps | 100% |
| Hodgdon Retumbo | 90.3 gr | 80% | 35,520 psi | 51% | 2612 fps | 98.9% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,398 psi | 41% | 1608 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 52,852 psi | 76% | 2753 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 80% | 58,769 psi | 84% | 2828 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 48,689 psi | 70% | 2684 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 46,079 psi | 66% | 2657 fps | 98.9% |
| IMR 7828 SSC | <<locked>> | 80% | 43,903 psi | 63% | 2710 fps | 99% |
| IMR 7977 Enduron | <<locked>> | 92% | 54,230 psi | 78% | 2766 fps | 95.6% |
| IMR 8133 Enduron | <<locked>> | 84% | 30,414 psi | 44% | 2431 fps | 95.1% |
| Lovex D100 | <<locked>> | 98% | 58,102 psi | 83% | 2867 fps | 95.4% |
| Lovex S065 | <<locked>> | 80% | 56,536 psi | 81% | 2779 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 54,940 psi | 79% | 2779 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 37,289 psi | 54% | 2484 fps | 99.8% |
| Norma 204 | <<locked>> | 80% | 53,737 psi | 77% | 2812 fps | 100% |
| Norma 217 | <<locked>> | 80% | 26,701 psi | 38% | 2343 fps | 95.6% |
| Norma MRP | <<locked>> | 80% | 45,861 psi | 66% | 2749 fps | 100% |
| Norma URP | <<locked>> | 80% | 54,926 psi | 79% | 2795 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 46,470 psi | 67% | 2769 fps | 99.6% |
| Ramshot Hunter | <<locked>> | 80% | 53,838 psi | 77% | 2805 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 40,843 psi | 59% | 2628 fps | 99.7% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,051 psi | 42% | 1644 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 56,971 psi | 82% | 2838 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 55,579 psi | 80% | 2867 fps | 100% |
| ReloadSwiss RS 76 | 96.6 gr | 80% | 34,635 psi | 50% | 2585 fps | 99.4% |
| ReloadSwiss RS 80 | <<locked>> | 82% | 34,142 psi | 49% | 2543 fps | 95.3% |
| Rottweil R 904 | <<locked>> | 80% | 48,008 psi | 69% | 2697 fps | 99.5% |
| Rottweil R 905 | <<locked>> | 80% | 46,789 psi | 67% | 2707 fps | 99.8% |
| Rottweil R 907 | <<locked>> | 80% | 57,537 psi | 83% | 2812 fps | 100% |
| Shooters World 50 BMG | <<locked>> | 98% | 58,102 psi | 83% | 2867 fps | 95.4% |
| Shooters World Long Rifle | <<locked>> | 80% | 56,536 psi | 81% | 2779 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 54,940 psi | 79% | 2779 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 55,288 psi | 79% | 2733 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 46,441 psi | 67% | 2703 fps | 99.8% |
| Somchem S361 | <<locked>> | 80% | 49,023 psi | 70% | 2690 fps | 99.2% |
| Somchem S365 | <<locked>> | 80% | 52,765 psi | 76% | 2749 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 47,224 psi | 68% | 2684 fps | 100% |
| Unknown powder | <<locked>> | 80% | 58,421 psi | 84% | 2848 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 54,027 psi | 78% | 2680 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 58,726 psi | 84% | 2812 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 40,030 psi | 57% | 2543 fps | 99.3% |
| Vihtavuori N170 | <<locked>> | 94% | 47,747 psi | 69% | 2713 fps | 95.8% |
| Vihtavuori N555 | <<locked>> | 80% | 46,572 psi | 67% | 2684 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 43,439 psi | 62% | 2707 fps | 98.5% |
| Vihtavuori N565 | <<locked>> | 80% | 37,869 psi | 54% | 2572 fps | 97.4% |
| Vihtavuori N568 | <<locked>> | 82% | 35,491 psi | 51% | 2559 fps | 95.2% |
| Vihtavuori N570 | 104.2 gr | 88% | 42,047 psi | 60% | 2736 fps | 95.5% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 55,608 psi | 80% | 2733 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 40,132 psi | 58% | 2677 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 47,340 psi | 68% | 2687 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 83 powders for .338 Lapua Mag. Ackley Improved loaded with the .338 | 250gr | Alaska Bullet Works Kodiak PP SPBC. Hodgdon Retumbo delivers the highest muzzle velocity at 3,081 fps; across all powders the maximum-charge window runs from 1,795 fps to 3,081 fps. Accurate 8700 gives the best case fill at 100 %, and 83 of the 83 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 1:16.0 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 | Alaska Bullet Works Kodiak PP SPBC 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.