Load Specifications
Load data in caliber .338 Lapua Mag. Ackley Improved with .338 | 225gr | Barnes MRX BT bullet and 84 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Accurate MAGPRO, ADI AR 2213 and Ramshot Grand.
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% | 59,480 psi | 85% | 2927 fps | 100% |
| Accurate 3100 | <<locked>> | 94% | 60,307 psi | 87% | 2992 fps | 100% |
| Accurate 4350 | <<locked>> | 86% | 61,293 psi | 88% | 3018 fps | 100% |
| Accurate MAGPRO | <<locked>> | 94% | 60,379 psi | 87% | 3120 fps | 99.3% |
| ADI APS 450 | <<locked>> | 82% | 61,105 psi | 88% | 2329 fps | 100% |
| ADI AR 2208 | <<locked>> | 82% | 61,206 psi | 88% | 2966 fps | 100% |
| ADI AR 2209 | <<locked>> | 92% | 62,627 psi | 90% | 3097 fps | 100% |
| ADI AR 2213 | <<locked>> | 94% | 60,539 psi | 87% | 3110 fps | 99.9% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 54,462 psi | 78% | 3012 fps | 99.8% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 48,878 psi | 70% | 2976 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 88% | 62,598 psi | 90% | 3074 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 82% | 59,785 psi | 86% | 3031 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 92% | 61,757 psi | 89% | 3081 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 94% | 60,510 psi | 87% | 3100 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 96% | 62,018 psi | 89% | 3048 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 62,076 psi | 89% | 3127 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 90% | 58,972 psi | 85% | 3097 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 51,300 psi | 74% | 3031 fps | 97.1% |
| Baschieri & Pellagri 109 | <<locked>> | 96% | 61,351 psi | 88% | 3068 fps | 98.8% |
| Bofors RP15 | <<locked>> | 96% | 59,611 psi | 86% | 3087 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 57,566 psi | 83% | 3084 fps | 100% |
| Bofors RP5 | <<locked>> | 94% | 60,510 psi | 87% | 3100 fps | 100% |
| Bofors RP7 | <<locked>> | 86% | 62,917 psi | 90% | 3022 fps | 100% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 56,057 psi | 81% | 3038 fps | 100% |
| Hodgdon H414 | <<locked>> | 82% | 60,046 psi | 86% | 3041 fps | 100% |
| Hodgdon H4350 | <<locked>> | 86% | 60,031 psi | 86% | 3018 fps | 100% |
| Hodgdon H4831 | <<locked>> | 96% | 59,306 psi | 85% | 3031 fps | 99.6% |
| Hodgdon H4831 SC | <<locked>> | 94% | 62,888 psi | 90% | 3081 fps | 99.8% |
| Hodgdon Hybrid 100V | <<locked>> | 90% | 62,642 psi | 90% | 2986 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 60,930 psi | 88% | 3219 fps | 100% |
| Hodgdon Superformance | <<locked>> | 84% | 60,292 psi | 87% | 3071 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,217 psi | 53% | 1873 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 60,075 psi | 86% | 2940 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 84% | 61,960 psi | 89% | 2986 fps | 100% |
| IMR 4350 | <<locked>> | 88% | 61,235 psi | 88% | 3012 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 84% | 60,539 psi | 87% | 2989 fps | 100% |
| IMR 4831 | <<locked>> | 92% | 62,830 psi | 90% | 3022 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 92% | 60,553 psi | 87% | 3018 fps | 99.7% |
| IMR 7828 SSC | <<locked>> | 92% | 58,740 psi | 84% | 3094 fps | 99.9% |
| IMR 7977 Enduronᴾ | <<locked>> | 100% | 62,946 psi | 90% | 3012 fps | 95.9% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 44,266 psi | 64% | 2881 fps | 98.5% |
| Lovex S065 | <<locked>> | 86% | 61,380 psi | 88% | 2982 fps | 100% |
| Lovex S070 | <<locked>> | 86% | 59,596 psi | 86% | 2986 fps | 100% |
| Lovex S071ᴾ | <<locked>> | 100% | 61,496 psi | 88% | 3009 fps | 100% |
| Norma 204 | <<locked>> | 88% | 62,990 psi | 90% | 3077 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 44,628 psi | 64% | 2904 fps | 99.8% |
| Norma MRP | <<locked>> | 92% | 60,785 psi | 87% | 3120 fps | 100% |
| Norma URP | <<locked>> | 86% | 59,451 psi | 85% | 3002 fps | 100% |
| Ramshot Grand | <<locked>> | 90% | 58,798 psi | 84% | 3097 fps | 100% |
| Ramshot Hunter | <<locked>> | 88% | 62,497 psi | 90% | 3071 fps | 100% |
| Ramshot Magnum | <<locked>> | 94% | 60,321 psi | 87% | 3068 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,189 psi | 55% | 1919 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 86% | 61,612 psi | 89% | 3045 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 86% | 60,481 psi | 87% | 3081 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 62,627 psi | 90% | 3215 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 57,029 psi | 82% | 3114 fps | 99.5% |
| Rottweil R 903 | <<locked>> | 82% | 60,597 psi | 87% | 2953 fps | 100% |
| Rottweil R 904 | <<locked>> | 90% | 59,277 psi | 85% | 3005 fps | 99.8% |
| Rottweil R 905 | <<locked>> | 92% | 61,366 psi | 88% | 3071 fps | 100% |
| Rottweil R 907 | <<locked>> | 86% | 62,917 psi | 90% | 3022 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 86% | 61,380 psi | 88% | 2982 fps | 100% |
| Shooters World SW4350 | <<locked>> | 86% | 59,596 psi | 86% | 2986 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 82% | 62,685 psi | 90% | 3018 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 82% | 59,799 psi | 86% | 2808 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 60,510 psi | 87% | 2940 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 92% | 60,945 psi | 88% | 3064 fps | 100% |
| Somchem S355 | <<locked>> | 82% | 60,133 psi | 86% | 2946 fps | 100% |
| Somchem S361 | <<locked>> | 90% | 61,134 psi | 88% | 2999 fps | 99.7% |
| Somchem S365 | <<locked>> | 88% | 60,597 psi | 87% | 2999 fps | 100% |
| Somchem S385 | <<locked>> | 92% | 61,757 psi | 89% | 3035 fps | 100% |
| Unknown powder | <<locked>> | 84% | 59,480 psi | 85% | 3002 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 62,337 psi | 90% | 2927 fps | 100% |
| Vihtavuori N160 | <<locked>> | 84% | 59,843 psi | 86% | 2966 fps | 100% |
| Vihtavuori N165 | <<locked>> | 96% | 59,611 psi | 86% | 2992 fps | 100% |
| Vihtavuori N550 | <<locked>> | 84% | 60,336 psi | 87% | 3015 fps | 100% |
| Vihtavuori N555 | <<locked>> | 92% | 60,046 psi | 86% | 3025 fps | 100% |
| Vihtavuori N560 | <<locked>> | 94% | 61,119 psi | 88% | 3140 fps | 99.9% |
| Vihtavuori N565 | <<locked>> | 98% | 60,394 psi | 87% | 3104 fps | 99.9% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 57,769 psi | 83% | 3117 fps | 99.3% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 55,201 psi | 79% | 3114 fps | 97.5% |
| Winchester 6.5 StaBALL | <<locked>> | 86% | 61,046 psi | 88% | 2940 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 60,046 psi | 86% | 3041 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 96% | 61,801 psi | 89% | 3146 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 90% | 59,582 psi | 86% | 3005 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% | 55,796 psi | 80% | 2874 fps | 100% |
| Accurate 3100 | <<locked>> | 80% | 37,188 psi | 53% | 2605 fps | 99.2% |
| Accurate 4350 | <<locked>> | 80% | 49,806 psi | 72% | 2854 fps | 100% |
| Accurate MAGPRO | 98.1 gr | 84% | 42,105 psi | 60% | 2799 fps | 95.8% |
| ADI APS 450 | <<locked>> | 80% | 59,161 psi | 85% | 2300 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 57,406 psi | 82% | 2913 fps | 100% |
| ADI AR 2209 | <<locked>> | 80% | 41,524 psi | 60% | 2743 fps | 98.3% |
| ADI AR 2213 | 88.9 gr | 80% | 37,086 psi | 53% | 2674 fps | 95.9% |
| ADI AR 2217 | <<locked>> | 88% | 36,027 psi | 52% | 2648 fps | 95.9% |
| ADI AR 2225 | <<locked>> | 84% | 28,340 psi | 41% | 2480 fps | 95.5% |
| Alliant Reloder-16 | <<locked>> | 80% | 47,921 psi | 69% | 2864 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 80% | 55,680 psi | 80% | 2976 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 41,568 psi | 60% | 2740 fps | 98.4% |
| Alliant Reloder-22 | <<locked>> | 80% | 37,434 psi | 54% | 2684 fps | 97.5% |
| Alliant Reloder-23 | <<locked>> | 80% | 36,071 psi | 52% | 2635 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 31,067 psi | 45% | 2556 fps | 98.5% |
| Alliant Reloder-26 | <<locked>> | 80% | 40,176 psi | 58% | 2792 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 96% | 44,106 psi | 63% | 2894 fps | 95.1% |
| Baschieri & Pellagri 109 | <<locked>> | 86% | 44,759 psi | 64% | 2776 fps | 95.3% |
| Bofors RP15 | <<locked>> | 80% | 34,780 psi | 50% | 2618 fps | 96.4% |
| Bofors RP30 | <<locked>> | 86% | 35,244 psi | 51% | 2657 fps | 96% |
| Bofors RP5 | <<locked>> | 80% | 37,434 psi | 54% | 2684 fps | 97.5% |
| Bofors RP7 | <<locked>> | 80% | 51,953 psi | 75% | 2858 fps | 100% |
| Hodgdon H1000 | <<locked>> | 86% | 34,519 psi | 50% | 2612 fps | 95.9% |
| Hodgdon H414 | <<locked>> | 80% | 56,101 psi | 81% | 2982 fps | 100% |
| Hodgdon H4350 | <<locked>> | 80% | 49,530 psi | 71% | 2854 fps | 99.7% |
| Hodgdon H4831 | <<locked>> | 82% | 37,333 psi | 54% | 2628 fps | 95.3% |
| Hodgdon H4831 SC | <<locked>> | 80% | 38,928 psi | 56% | 2667 fps | 95.9% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 45,107 psi | 65% | 2740 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 80% | 30,356 psi | 44% | 2575 fps | 95.1% |
| Hodgdon Superformance | <<locked>> | 80% | 51,895 psi | 75% | 2946 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,862 psi | 40% | 1677 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 56,608 psi | 81% | 2894 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 54,810 psi | 79% | 2884 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 47,340 psi | 68% | 2792 fps | 99.7% |
| IMR 4451 Enduron | <<locked>> | 80% | 53,461 psi | 77% | 2884 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 42,902 psi | 62% | 2723 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 41,075 psi | 59% | 2680 fps | 96.7% |
| IMR 7828 SSC | <<locked>> | 80% | 38,058 psi | 55% | 2710 fps | 96.4% |
| IMR 7977 Enduron | <<locked>> | 98% | 58,871 psi | 85% | 2949 fps | 95% |
| IMR 8133 Enduron | <<locked>> | 92% | 33,504 psi | 48% | 2635 fps | 95% |
| Lovex S065 | <<locked>> | 80% | 50,792 psi | 73% | 2828 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 49,226 psi | 71% | 2828 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 31,850 psi | 46% | 2480 fps | 97.9% |
| Norma 204 | <<locked>> | 80% | 47,805 psi | 69% | 2841 fps | 99.3% |
| Norma 217 | <<locked>> | 88% | 29,196 psi | 42% | 2536 fps | 95.4% |
| Norma MRP | <<locked>> | 80% | 39,479 psi | 57% | 2756 fps | 99.1% |
| Norma URP | <<locked>> | 80% | 48,805 psi | 70% | 2844 fps | 100% |
| Ramshot Grand | 94.6 gr | 80% | 39,769 psi | 57% | 2762 fps | 97.4% |
| Ramshot Hunter | <<locked>> | 80% | 47,718 psi | 69% | 2848 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 34,664 psi | 50% | 2618 fps | 97.5% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,543 psi | 41% | 1716 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 50,024 psi | 72% | 2881 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 48,544 psi | 70% | 2907 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 29,341 psi | 42% | 2546 fps | 96% |
| ReloadSwiss RS 80 | <<locked>> | 90% | 38,522 psi | 55% | 2769 fps | 95.6% |
| Rottweil R 903 | <<locked>> | 80% | 56,913 psi | 82% | 2904 fps | 100% |
| Rottweil R 904 | <<locked>> | 80% | 42,801 psi | 61% | 2723 fps | 97.7% |
| Rottweil R 905 | <<locked>> | 80% | 41,017 psi | 59% | 2726 fps | 98.4% |
| Rottweil R 907 | <<locked>> | 80% | 51,953 psi | 75% | 2858 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 80% | 50,792 psi | 73% | 2828 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 49,226 psi | 71% | 2828 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 58,624 psi | 84% | 2966 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 56,188 psi | 81% | 2766 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 49,705 psi | 71% | 2779 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 40,683 psi | 58% | 2723 fps | 98.3% |
| Somchem S355 | <<locked>> | 80% | 56,376 psi | 81% | 2897 fps | 100% |
| Somchem S361 | <<locked>> | 80% | 43,598 psi | 63% | 2710 fps | 97.2% |
| Somchem S365 | <<locked>> | 80% | 46,006 psi | 66% | 2795 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 41,423 psi | 60% | 2703 fps | 99% |
| Unknown powder | <<locked>> | 80% | 52,098 psi | 75% | 2897 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 48,617 psi | 70% | 2740 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 52,272 psi | 75% | 2861 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 34,925 psi | 50% | 2552 fps | 97.2% |
| Vihtavuori N550 | <<locked>> | 80% | 52,852 psi | 76% | 2910 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 40,292 psi | 58% | 2713 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 37,434 psi | 54% | 2700 fps | 95.5% |
| Vihtavuori N565 | <<locked>> | 84% | 37,072 psi | 53% | 2677 fps | 95.7% |
| Vihtavuori N568 | <<locked>> | 90% | 40,030 psi | 57% | 2789 fps | 95.4% |
| Vihtavuori N570 | <<locked>> | 96% | 47,456 psi | 68% | 2972 fps | 95.7% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 49,530 psi | 71% | 2789 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 56,101 psi | 81% | 2982 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 32,808 psi | 47% | 2674 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 41,452 psi | 60% | 2703 fps | 98.4% |
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 90 powders for .338 Lapua Mag. Ackley Improved loaded with the .338 | 225gr | Barnes MRX BT. Hodgdon Retumbo delivers the highest muzzle velocity at 3,219 fps; across all powders the maximum-charge window runs from 1,873 fps to 3,219 fps. ADI AR 2217 gives the best case fill at 100 %, and 90 of the 90 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (480 MPa), the top charges use 53–90 %, leaving at least 10 % headroom. The 225.0 gr projectile in 0.338" calls for a 1:13.5 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. Accurate MAGPRO, ADI AR 2213, Ramshot Grand rank at the top here: for .338 Lapua Mag. Ackley Improved with the .338 | 225gr | Barnes MRX BT they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Alliant Reloder-50, Lovex D100, Shooters World 50 BMG 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.