Load Specifications
Load data in caliber .338 Lapua Mag. Ackley Improved with .338 | 250gr | Barnes LRX BT bullet and 86 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 N560.
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 2700 | <<locked>> | 82% | 61,670 psi | 89% | 2808 fps | 100% |
| Accurate 3100 | <<locked>> | 92% | 58,958 psi | 85% | 2831 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 59,770 psi | 86% | 2848 fps | 100% |
| Accurate MAGPRO | <<locked>> | 92% | 58,856 psi | 85% | 2959 fps | 99.6% |
| ADI APS 450 | <<locked>> | 82% | 61,206 psi | 88% | 2195 fps | 100% |
| ADI AR 2209 | <<locked>> | 90% | 60,887 psi | 87% | 2927 fps | 100% |
| ADI AR 2213 | <<locked>> | 92% | 59,016 psi | 85% | 2943 fps | 100% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 57,101 psi | 82% | 2913 fps | 100% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 49,516 psi | 71% | 2897 fps | 97.6% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 51,358 psi | 74% | 2877 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 90% | 60,292 psi | 87% | 2910 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 86% | 61,250 psi | 88% | 2904 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 82% | 62,395 psi | 90% | 2910 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 90% | 60,365 psi | 87% | 2913 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 92% | 59,132 psi | 85% | 2933 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 94% | 60,727 psi | 87% | 2881 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 98% | 60,959 psi | 88% | 2959 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 90% | 62,091 psi | 89% | 2986 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 54,215 psi | 78% | 2949 fps | 98.5% |
| Alliant Reloder-50ᴾ | <<locked>> | 100% | 45,440 psi | 65% | 2795 fps | 96.1% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 59,741 psi | 86% | 2907 fps | 99.1% |
| Bofors RP15 | <<locked>> | 96% | 62,178 psi | 89% | 2972 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 60,553 psi | 87% | 2982 fps | 100% |
| Bofors RP5 | <<locked>> | 92% | 59,132 psi | 85% | 2933 fps | 100% |
| Bofors RP7 | <<locked>> | 84% | 61,192 psi | 88% | 2851 fps | 100% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 58,798 psi | 84% | 2936 fps | 100% |
| Hodgdon H414 | <<locked>> | 82% | 62,526 psi | 90% | 2923 fps | 100% |
| Hodgdon H4350 | <<locked>> | 86% | 62,120 psi | 89% | 2897 fps | 100% |
| Hodgdon H4831 | <<locked>> | 96% | 61,960 psi | 89% | 2927 fps | 100% |
| Hodgdon H4831 SC | <<locked>> | 92% | 61,192 psi | 88% | 2917 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 88% | 61,134 psi | 88% | 2818 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 59,857 psi | 86% | 3054 fps | 100% |
| Hodgdon Superformance | <<locked>> | 84% | 62,903 psi | 90% | 2956 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,434 psi | 54% | 1768 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 62,250 psi | 89% | 2815 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 60,220 psi | 87% | 2815 fps | 100% |
| IMR 4350 | <<locked>> | 86% | 59,553 psi | 86% | 2841 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 84% | 61,873 psi | 89% | 2854 fps | 100% |
| IMR 4831 | <<locked>> | 90% | 61,467 psi | 88% | 2858 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 92% | 61,859 psi | 89% | 2890 fps | 100% |
| IMR 7828 SSC | <<locked>> | 92% | 61,424 psi | 88% | 2982 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 98% | 60,365 psi | 87% | 2838 fps | 96.3% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 46,891 psi | 67% | 2799 fps | 99.5% |
| Lovex S065 | <<locked>> | 84% | 59,727 psi | 86% | 2812 fps | 100% |
| Lovex S070 | <<locked>> | 86% | 61,728 psi | 89% | 2864 fps | 100% |
| Lovex S071 | <<locked>> | 98% | 60,278 psi | 87% | 2844 fps | 100% |
| Norma 204 | <<locked>> | 86% | 61,163 psi | 88% | 2907 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 47,529 psi | 68% | 2822 fps | 100% |
| Norma MRP | <<locked>> | 90% | 59,350 psi | 85% | 2953 fps | 100% |
| Norma URP | <<locked>> | 86% | 61,743 psi | 89% | 2881 fps | 100% |
| Ramshot Grand | <<locked>> | 90% | 61,989 psi | 89% | 2992 fps | 100% |
| Ramshot Hunter | <<locked>> | 86% | 60,843 psi | 87% | 2897 fps | 100% |
| Ramshot Magnum | <<locked>> | 92% | 58,711 psi | 84% | 2904 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,348 psi | 55% | 1811 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 60,162 psi | 86% | 2874 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 84% | 58,813 psi | 84% | 2907 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 61,046 psi | 88% | 3045 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 60,147 psi | 86% | 3018 fps | 100% |
| Rottweil R 903 | <<locked>> | 82% | 62,917 psi | 90% | 2828 fps | 100% |
| Rottweil R 904 | <<locked>> | 90% | 61,569 psi | 88% | 2894 fps | 100% |
| Rottweil R 905 | <<locked>> | 90% | 59,915 psi | 86% | 2904 fps | 100% |
| Rottweil R 907 | <<locked>> | 84% | 61,192 psi | 88% | 2851 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 84% | 59,727 psi | 86% | 2812 fps | 100% |
| Shooters World SW4350 | <<locked>> | 86% | 61,046 psi | 88% | 2851 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 82% | 61,844 psi | 89% | 2687 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 62,671 psi | 90% | 2822 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 92% | 62,700 psi | 90% | 2936 fps | 100% |
| Somchem S355 | <<locked>> | 82% | 62,236 psi | 89% | 2822 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 59,234 psi | 85% | 2835 fps | 99.9% |
| Somchem S365 | <<locked>> | 86% | 59,161 psi | 85% | 2831 fps | 100% |
| Somchem S385 | <<locked>> | 90% | 60,234 psi | 87% | 2871 fps | 100% |
| Unknown powder | <<locked>> | 84% | 61,859 psi | 89% | 2884 fps | 100% |
| Vihtavuori N150 | <<locked>> | 86% | 60,684 psi | 87% | 2759 fps | 100% |
| Vihtavuori N160 | <<locked>> | 84% | 62,149 psi | 89% | 2844 fps | 100% |
| Vihtavuori N165 | <<locked>> | 96% | 62,018 psi | 89% | 2877 fps | 100% |
| Vihtavuori N170ᴾ | <<locked>> | 100% | 52,779 psi | 76% | 2792 fps | 96.6% |
| Vihtavuori N550 | <<locked>> | 84% | 62,656 psi | 90% | 2894 fps | 100% |
| Vihtavuori N555 | <<locked>> | 92% | 62,830 psi | 90% | 2910 fps | 100% |
| Vihtavuori N560 | <<locked>> | 92% | 59,669 psi | 86% | 2972 fps | 100% |
| Vihtavuori N565 | <<locked>> | 96% | 59,190 psi | 85% | 2943 fps | 100% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 60,640 psi | 87% | 3015 fps | 99.8% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 58,175 psi | 84% | 3022 fps | 98.8% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 59,306 psi | 85% | 2772 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 62,526 psi | 90% | 2923 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 94% | 60,756 psi | 87% | 2979 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 90% | 62,163 psi | 89% | 2894 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 2700 | <<locked>> | 80% | 57,754 psi | 83% | 2759 fps | 100% |
| Accurate 3100 | <<locked>> | 80% | 39,117 psi | 56% | 2520 fps | 99.9% |
| Accurate 4350 | <<locked>> | 80% | 52,199 psi | 75% | 2746 fps | 100% |
| Accurate MAGPRO | <<locked>> | 80% | 38,319 psi | 55% | 2592 fps | 95.6% |
| ADI APS 450 | <<locked>> | 80% | 59,176 psi | 85% | 2169 fps | 100% |
| ADI AR 2209 | <<locked>> | 80% | 43,497 psi | 62% | 2651 fps | 99.3% |
| ADI AR 2213 | <<locked>> | 80% | 38,827 psi | 56% | 2592 fps | 97.6% |
| ADI AR 2217 | <<locked>> | 84% | 32,866 psi | 47% | 2451 fps | 95.8% |
| ADI AR 2218 | <<locked>> | 96% | 42,786 psi | 61% | 2759 fps | 95.4% |
| ADI AR 2225 | <<locked>> | 80% | 26,034 psi | 37% | 2300 fps | 95.4% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 43,236 psi | 62% | 2638 fps | 99.2% |
| Alliant Reloder-16 | <<locked>> | 80% | 50,270 psi | 72% | 2753 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 80% | 58,218 psi | 84% | 2861 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 43,511 psi | 63% | 2648 fps | 99.3% |
| Alliant Reloder-22 | <<locked>> | 80% | 39,334 psi | 56% | 2598 fps | 98.7% |
| Alliant Reloder-23 | <<locked>> | 80% | 38,014 psi | 55% | 2543 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 32,735 psi | 47% | 2480 fps | 99.6% |
| Alliant Reloder-26 | <<locked>> | 80% | 42,525 psi | 61% | 2700 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 94% | 43,221 psi | 62% | 2753 fps | 96% |
| Alliant Reloder-50 | <<locked>> | 98% | 42,061 psi | 60% | 2730 fps | 95% |
| Baschieri & Pellagri 109 | <<locked>> | 82% | 40,770 psi | 59% | 2572 fps | 95.1% |
| Bofors RP15 | <<locked>> | 80% | 36,492 psi | 52% | 2536 fps | 97.9% |
| Bofors RP30 | <<locked>> | 82% | 32,372 psi | 47% | 2467 fps | 95.9% |
| Bofors RP5 | <<locked>> | 80% | 39,334 psi | 56% | 2598 fps | 98.7% |
| Bofors RP7 | <<locked>> | 80% | 53,853 psi | 77% | 2746 fps | 100% |
| Hodgdon H1000 | <<locked>> | 82% | 31,517 psi | 45% | 2418 fps | 95.8% |
| Hodgdon H414 | <<locked>> | 80% | 58,465 psi | 84% | 2871 fps | 100% |
| Hodgdon H4350 | <<locked>> | 80% | 51,488 psi | 74% | 2746 fps | 100% |
| Hodgdon H4831 | <<locked>> | 80% | 36,535 psi | 52% | 2490 fps | 96.1% |
| Hodgdon H4831 SC | <<locked>> | 80% | 40,698 psi | 58% | 2579 fps | 97.4% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 47,079 psi | 68% | 2631 fps | 100% |
| Hodgdon Retumbo | 85.2 gr | 80% | 31,923 psi | 46% | 2513 fps | 97.4% |
| Hodgdon Superformance | <<locked>> | 80% | 54,273 psi | 78% | 2841 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,094 psi | 40% | 1585 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 58,552 psi | 84% | 2769 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 56,695 psi | 81% | 2766 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 49,240 psi | 71% | 2690 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 80% | 54,665 psi | 79% | 2756 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 44,875 psi | 64% | 2621 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 42,177 psi | 61% | 2572 fps | 97.8% |
| IMR 7828 SSC | <<locked>> | 80% | 40,016 psi | 57% | 2631 fps | 98% |
| IMR 7977 Enduron | <<locked>> | 96% | 56,521 psi | 81% | 2779 fps | 95.5% |
| IMR 8133 Enduron | <<locked>> | 88% | 30,893 psi | 44% | 2451 fps | 95% |
| Lovex S065 | <<locked>> | 80% | 52,649 psi | 76% | 2713 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 51,039 psi | 73% | 2717 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 33,620 psi | 48% | 2405 fps | 99.1% |
| Norma 204 | <<locked>> | 80% | 49,777 psi | 72% | 2740 fps | 99.8% |
| Norma 217 | <<locked>> | 84% | 27,006 psi | 39% | 2356 fps | 95.5% |
| Norma MRP | <<locked>> | 80% | 41,597 psi | 60% | 2667 fps | 99.8% |
| Norma URP | <<locked>> | 80% | 50,778 psi | 73% | 2730 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 41,916 psi | 60% | 2680 fps | 98.8% |
| Ramshot Hunter | <<locked>> | 80% | 49,748 psi | 71% | 2740 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 36,506 psi | 52% | 2539 fps | 98.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,718 psi | 41% | 1621 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 52,330 psi | 75% | 2772 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 50,894 psi | 73% | 2799 fps | 100% |
| ReloadSwiss RS 76 | 91.2 gr | 80% | 30,922 psi | 44% | 2484 fps | 98.1% |
| ReloadSwiss RS 80 | <<locked>> | 86% | 35,070 psi | 50% | 2569 fps | 95.4% |
| Rottweil R 903 | <<locked>> | 80% | 58,958 psi | 85% | 2782 fps | 100% |
| Rottweil R 904 | <<locked>> | 80% | 44,585 psi | 64% | 2628 fps | 98.8% |
| Rottweil R 905 | <<locked>> | 80% | 42,844 psi | 62% | 2631 fps | 99.3% |
| Rottweil R 907 | <<locked>> | 80% | 53,853 psi | 77% | 2746 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 80% | 52,649 psi | 76% | 2713 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 50,488 psi | 73% | 2703 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 58,160 psi | 84% | 2644 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 51,634 psi | 74% | 2671 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 41,959 psi | 60% | 2615 fps | 99.2% |
| Somchem S355 | <<locked>> | 80% | 58,421 psi | 84% | 2776 fps | 100% |
| Somchem S361 | <<locked>> | 80% | 45,295 psi | 65% | 2615 fps | 98.4% |
| Somchem S365 | <<locked>> | 80% | 48,298 psi | 69% | 2687 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 43,279 psi | 62% | 2608 fps | 99.7% |
| Unknown powder | <<locked>> | 80% | 54,360 psi | 78% | 2782 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 50,430 psi | 72% | 2625 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 54,462 psi | 78% | 2746 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 36,506 psi | 52% | 2467 fps | 98.5% |
| Vihtavuori N170 | <<locked>> | 96% | 46,340 psi | 67% | 2680 fps | 95% |
| Vihtavuori N550 | <<locked>> | 80% | 55,042 psi | 79% | 2795 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 42,322 psi | 61% | 2612 fps | 100% |
| Vihtavuori N560 | 86.6 gr | 80% | 39,407 psi | 57% | 2618 fps | 97.3% |
| Vihtavuori N565 | <<locked>> | 80% | 33,997 psi | 49% | 2484 fps | 95.7% |
| Vihtavuori N568 | <<locked>> | 86% | 36,521 psi | 52% | 2589 fps | 95.3% |
| Vihtavuori N570 | <<locked>> | 92% | 43,352 psi | 62% | 2762 fps | 95.6% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 51,590 psi | 74% | 2674 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 58,465 psi | 84% | 2871 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 35,186 psi | 51% | 2592 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 43,381 psi | 62% | 2612 fps | 99.3% |
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 | 250gr | Barnes LRX BT. Hodgdon Retumbo delivers the highest muzzle velocity at 3,054 fps; across all powders the maximum-charge window runs from 1,768 fps to 3,054 fps. ADI AR 2217 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 250.0 gr projectile in 0.338" calls for a 1:11.0 twist; slower twists will usually not stabilise this weight. ADI AR 2217, 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. Hodgdon Retumbo, ReloadSwiss RS 76, Vihtavuori N560 rank at the top here: for .338 Lapua Mag. Ackley Improved with the .338 | 250gr | Barnes LRX BT they combine a high case fill with complete burn and sit in the upper velocity band. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.