Load Specifications
Load data in caliber .338 Lapua Mag. Ackley Improved with .338 | 225gr | Barnes XLC S 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 Winchester StaBALL HD.
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% | 59,524 psi | 86% | 2963 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 59,944 psi | 86% | 2982 fps | 100% |
| Accurate MAGPRO | <<locked>> | 92% | 62,453 psi | 90% | 3136 fps | 99.5% |
| ADI APS 450 | <<locked>> | 82% | 61,395 psi | 88% | 2336 fps | 100% |
| ADI AR 2209 | <<locked>> | 88% | 59,640 psi | 86% | 3041 fps | 100% |
| ADI AR 2213 | <<locked>> | 92% | 61,873 psi | 89% | 3117 fps | 100% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 60,147 psi | 86% | 3084 fps | 100% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 52,881 psi | 76% | 3074 fps | 97.5% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 54,868 psi | 79% | 3058 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 84% | 59,872 psi | 86% | 3025 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 59,248 psi | 85% | 3031 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 92% | 62,468 psi | 90% | 3110 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 92% | 60,408 psi | 87% | 3012 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 96% | 60,220 psi | 87% | 3087 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 88% | 61,627 psi | 89% | 3114 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 58,117 psi | 83% | 3133 fps | 98.5% |
| Alliant Reloder-50ᴾ | <<locked>> | 100% | 50,415 psi | 72% | 2995 fps | 96.5% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 61,960 psi | 89% | 3068 fps | 98.9% |
| Bofors RP15 | <<locked>> | 94% | 61,540 psi | 88% | 3100 fps | 100% |
| Bofors RP30 | <<locked>> | 98% | 60,278 psi | 87% | 3107 fps | 100% |
| Bofors RP5 | <<locked>> | 92% | 62,468 psi | 90% | 3110 fps | 100% |
| Bofors RP7 | <<locked>> | 82% | 60,292 psi | 87% | 2969 fps | 100% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 61,830 psi | 89% | 3107 fps | 100% |
| Hodgdon H4350 | <<locked>> | 84% | 60,814 psi | 87% | 3015 fps | 100% |
| Hodgdon H4831 | <<locked>> | 94% | 60,771 psi | 87% | 3041 fps | 99.7% |
| Hodgdon H4831 SC | <<locked>> | 90% | 60,104 psi | 86% | 3031 fps | 99.7% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 60,365 psi | 87% | 2943 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 96% | 59,030 psi | 85% | 3179 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 61,424 psi | 88% | 3071 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,782 psi | 54% | 1880 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 62,453 psi | 90% | 2979 fps | 100% |
| IMR 4350 | <<locked>> | 86% | 62,163 psi | 89% | 3009 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 82% | 61,177 psi | 88% | 2986 fps | 100% |
| IMR 4831 | <<locked>> | 88% | 61,177 psi | 88% | 2986 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 61,293 psi | 88% | 3018 fps | 99.8% |
| IMR 7828 SSC | <<locked>> | 90% | 60,234 psi | 87% | 3100 fps | 100% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 50,807 psi | 73% | 2982 fps | 99.5% |
| Lovex S065 | <<locked>> | 84% | 62,627 psi | 90% | 2982 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 61,264 psi | 88% | 2992 fps | 100% |
| Lovex S071 | <<locked>> | 96% | 60,814 psi | 87% | 2979 fps | 100% |
| Norma 204 | <<locked>> | 84% | 59,843 psi | 86% | 3022 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 51,648 psi | 74% | 3009 fps | 100% |
| Norma MRP | <<locked>> | 90% | 62,787 psi | 90% | 3130 fps | 100% |
| Norma URP | <<locked>> | 84% | 61,061 psi | 88% | 3009 fps | 100% |
| Ramshot Grand | <<locked>> | 88% | 60,611 psi | 87% | 3110 fps | 100% |
| Ramshot Hunter | <<locked>> | 84% | 59,814 psi | 86% | 3018 fps | 100% |
| Ramshot Magnum | <<locked>> | 92% | 62,236 psi | 89% | 3077 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,870 psi | 56% | 1926 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 59,611 psi | 86% | 2999 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 84% | 61,786 psi | 89% | 3084 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 60,234 psi | 87% | 3173 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 59,814 psi | 86% | 3140 fps | 99.7% |
| Rottweil R 904 | <<locked>> | 88% | 60,452 psi | 87% | 3009 fps | 99.9% |
| Rottweil R 905 | <<locked>> | 88% | 59,335 psi | 85% | 3025 fps | 100% |
| Rottweil R 907 | <<locked>> | 82% | 60,292 psi | 87% | 2969 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 84% | 62,627 psi | 90% | 2982 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 61,264 psi | 88% | 2992 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 61,786 psi | 89% | 2940 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 62,685 psi | 90% | 3074 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 62,076 psi | 89% | 2999 fps | 99.8% |
| Somchem S365 | <<locked>> | 86% | 62,671 psi | 90% | 3009 fps | 100% |
| Somchem S385 | <<locked>> | 88% | 59,915 psi | 86% | 2995 fps | 100% |
| Unknown powder | <<locked>> | 82% | 60,901 psi | 87% | 3009 fps | 100% |
| Vihtavuori N150 | <<locked>> | 84% | 60,031 psi | 86% | 2884 fps | 100% |
| Vihtavuori N160 | <<locked>> | 82% | 61,061 psi | 88% | 2966 fps | 100% |
| Vihtavuori N165 | <<locked>> | 94% | 61,308 psi | 88% | 2999 fps | 100% |
| Vihtavuori N170ᴾ | <<locked>> | 100% | 56,492 psi | 81% | 2966 fps | 96.5% |
| Vihtavuori N550 | <<locked>> | 82% | 61,873 psi | 89% | 3022 fps | 100% |
| Vihtavuori N555 | <<locked>> | 90% | 62,830 psi | 90% | 3041 fps | 100% |
| Vihtavuori N560 | <<locked>> | 92% | 62,743 psi | 90% | 3150 fps | 99.9% |
| Vihtavuori N565 | <<locked>> | 94% | 59,277 psi | 85% | 3071 fps | 99.8% |
| Vihtavuori N568 | <<locked>> | 98% | 60,191 psi | 86% | 3136 fps | 99.5% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 62,033 psi | 89% | 3205 fps | 98.7% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 61,960 psi | 89% | 2936 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 92% | 60,104 psi | 86% | 3110 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 88% | 60,930 psi | 88% | 3009 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% | 43,453 psi | 62% | 2710 fps | 99.9% |
| Accurate 4350 | <<locked>> | 80% | 56,159 psi | 81% | 2930 fps | 100% |
| Accurate MAGPRO | <<locked>> | 80% | 41,843 psi | 60% | 2772 fps | 95.8% |
| ADI APS 450 | <<locked>> | 80% | 59,321 psi | 85% | 2306 fps | 100% |
| ADI AR 2209 | <<locked>> | 80% | 46,224 psi | 66% | 2822 fps | 99.2% |
| ADI AR 2213 | <<locked>> | 80% | 41,771 psi | 60% | 2766 fps | 97.5% |
| ADI AR 2217 | <<locked>> | 82% | 33,939 psi | 49% | 2572 fps | 95.1% |
| ADI AR 2218 | <<locked>> | 96% | 46,108 psi | 66% | 2936 fps | 95.4% |
| ADI AR 2225 | <<locked>> | 80% | 29,501 psi | 42% | 2497 fps | 96.4% |
| Alliant Reloder-16 | <<locked>> | 80% | 52,895 psi | 76% | 2927 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 46,325 psi | 67% | 2815 fps | 99.3% |
| Alliant Reloder-22 | <<locked>> | 80% | 42,685 psi | 61% | 2779 fps | 98.8% |
| Alliant Reloder-23 | <<locked>> | 80% | 41,524 psi | 60% | 2723 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 36,071 psi | 52% | 2664 fps | 99.7% |
| Alliant Reloder-26 | <<locked>> | 80% | 46,514 psi | 67% | 2887 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 92% | 43,932 psi | 63% | 2874 fps | 95.1% |
| Alliant Reloder-50 | <<locked>> | 98% | 47,036 psi | 68% | 2933 fps | 95.6% |
| Baschieri & Pellagri 109 | <<locked>> | 84% | 45,905 psi | 66% | 2789 fps | 95.7% |
| Bofors RP15 | <<locked>> | 80% | 39,943 psi | 57% | 2720 fps | 98.1% |
| Bofors RP30 | <<locked>> | 80% | 33,852 psi | 49% | 2602 fps | 95.5% |
| Bofors RP5 | <<locked>> | 80% | 42,685 psi | 61% | 2779 fps | 98.8% |
| Bofors RP7 | <<locked>> | 80% | 56,753 psi | 82% | 2920 fps | 100% |
| Hodgdon H1000 | <<locked>> | 80% | 32,677 psi | 47% | 2539 fps | 95.2% |
| Hodgdon H4350 | <<locked>> | 80% | 54,041 psi | 78% | 2913 fps | 99.9% |
| Hodgdon H4831 | <<locked>> | 80% | 39,450 psi | 57% | 2657 fps | 96.2% |
| Hodgdon H4831 SC | <<locked>> | 80% | 43,598 psi | 63% | 2749 fps | 97.4% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 50,154 psi | 72% | 2802 fps | 100% |
| Hodgdon Retumbo | 89.6 gr | 80% | 35,317 psi | 51% | 2703 fps | 97.8% |
| Hodgdon Superformance | <<locked>> | 80% | 57,217 psi | 82% | 3012 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,456 psi | 41% | 1683 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 58,827 psi | 85% | 2930 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 51,793 psi | 74% | 2854 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 80% | 57,609 psi | 83% | 2933 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 48,196 psi | 69% | 2795 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 45,353 psi | 65% | 2749 fps | 97.9% |
| IMR 7828 SSC | <<locked>> | 80% | 42,960 psi | 62% | 2802 fps | 97.9% |
| IMR 8133 Enduron | <<locked>> | 88% | 34,780 psi | 50% | 2648 fps | 95.7% |
| Lovex S065 | <<locked>> | 80% | 55,782 psi | 80% | 2887 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 54,404 psi | 78% | 2890 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 37,956 psi | 55% | 2598 fps | 99.4% |
| Norma 204 | <<locked>> | 80% | 52,562 psi | 76% | 2910 fps | 99.8% |
| Norma 217 | <<locked>> | 82% | 29,211 psi | 42% | 2510 fps | 95.6% |
| Norma MRP | <<locked>> | 80% | 45,078 psi | 65% | 2851 fps | 99.8% |
| Norma URP | <<locked>> | 80% | 54,041 psi | 78% | 2907 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 45,237 psi | 65% | 2861 fps | 98.8% |
| Ramshot Hunter | <<locked>> | 80% | 52,707 psi | 76% | 2913 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 40,263 psi | 58% | 2723 fps | 99% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,254 psi | 42% | 1726 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 55,927 psi | 80% | 2949 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 53,809 psi | 77% | 2972 fps | 100% |
| ReloadSwiss RS 76 | 95.9 gr | 80% | 34,621 psi | 50% | 2680 fps | 98.6% |
| ReloadSwiss RS 80 | <<locked>> | 86% | 39,059 psi | 56% | 2762 fps | 95.9% |
| Rottweil R 904 | <<locked>> | 80% | 47,340 psi | 68% | 2792 fps | 98.7% |
| Rottweil R 905 | <<locked>> | 80% | 46,064 psi | 66% | 2808 fps | 99.3% |
| Rottweil R 907 | <<locked>> | 80% | 56,753 psi | 82% | 2920 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 80% | 55,782 psi | 80% | 2887 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 54,404 psi | 78% | 2890 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 54,636 psi | 78% | 2838 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 45,701 psi | 66% | 2802 fps | 99.3% |
| Somchem S361 | <<locked>> | 80% | 48,269 psi | 69% | 2779 fps | 98.3% |
| Somchem S365 | <<locked>> | 80% | 51,793 psi | 74% | 2861 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 46,775 psi | 67% | 2785 fps | 99.7% |
| Unknown powder | <<locked>> | 80% | 57,116 psi | 82% | 2953 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 53,447 psi | 77% | 2792 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 57,493 psi | 83% | 2920 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 39,856 psi | 57% | 2641 fps | 98.6% |
| Vihtavuori N170 | <<locked>> | 96% | 50,082 psi | 72% | 2858 fps | 95% |
| Vihtavuori N550 | <<locked>> | 80% | 58,247 psi | 84% | 2969 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 46,398 psi | 67% | 2799 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 42,728 psi | 61% | 2802 fps | 97.3% |
| Vihtavuori N565 | <<locked>> | 80% | 37,884 psi | 54% | 2674 fps | 96.2% |
| Vihtavuori N568 | <<locked>> | 86% | 40,234 psi | 58% | 2776 fps | 95.6% |
| Vihtavuori N570 | <<locked>> | 92% | 47,123 psi | 68% | 2953 fps | 95.7% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 54,360 psi | 78% | 2838 fps | 100% |
| Winchester StaBALL HD | 92 gr | 80% | 39,131 psi | 56% | 2789 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 46,586 psi | 67% | 2785 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 83 powders for .338 Lapua Mag. Ackley Improved loaded with the .338 | 225gr | Barnes XLC S. Vihtavuori N570 delivers the highest muzzle velocity at 3,205 fps; across all powders the maximum-charge window runs from 1,880 fps to 3,205 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 225.0 gr projectile in 0.338" calls for a 1:14.0 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, Winchester StaBALL HD rank at the top here: for .338 Lapua Mag. Ackley Improved with the .338 | 225gr | Barnes XLC S they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Accurate 8700, Lovex D100, 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.