Load Specifications
Load data in caliber .338 Lapua Mag. Ackley Improved with .338 | 265gr | Barnes TAC-TX BT bullet and 79 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.
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Max Load - Barrel Length: 27"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2700 | <<locked>> | 82% | 62,671 psi | 90% | 2743 fps | 100% |
| Accurate 3100 | <<locked>> | 92% | 60,089 psi | 86% | 2762 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 60,916 psi | 88% | 2779 fps | 100% |
| Accurate MAGPRO | <<locked>> | 92% | 60,191 psi | 86% | 2897 fps | 99.8% |
| ADI APS 450 | <<locked>> | 82% | 61,250 psi | 88% | 2136 fps | 100% |
| ADI AR 2209 | <<locked>> | 90% | 62,062 psi | 89% | 2858 fps | 100% |
| ADI AR 2213 | <<locked>> | 92% | 60,249 psi | 87% | 2877 fps | 100% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 58,479 psi | 84% | 2854 fps | 100% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 50,517 psi | 73% | 2848 fps | 98.4% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 52,576 psi | 76% | 2818 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 86% | 62,366 psi | 90% | 2831 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 90% | 61,322 psi | 88% | 2844 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 92% | 60,336 psi | 87% | 2867 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 94% | 62,149 psi | 89% | 2815 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 98% | 62,381 psi | 90% | 2890 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 88% | 59,059 psi | 85% | 2864 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 55,767 psi | 80% | 2897 fps | 99.1% |
| Alliant Reloder-50ᴾ | <<locked>> | 100% | 46,673 psi | 67% | 2749 fps | 97% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 60,858 psi | 87% | 2844 fps | 99.5% |
| Bofors RP15 | <<locked>> | 94% | 59,422 psi | 85% | 2858 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 61,873 psi | 89% | 2917 fps | 100% |
| Bofors RP5 | <<locked>> | 92% | 60,336 psi | 87% | 2867 fps | 100% |
| Bofors RP7 | <<locked>> | 84% | 62,076 psi | 89% | 2779 fps | 100% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 60,205 psi | 86% | 2871 fps | 100% |
| Hodgdon H4350 | <<locked>> | 84% | 59,553 psi | 86% | 2782 fps | 100% |
| Hodgdon H4831 | <<locked>> | 96% | 62,946 psi | 90% | 2858 fps | 100% |
| Hodgdon H4831 SC | <<locked>> | 92% | 62,337 psi | 90% | 2851 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 88% | 62,279 psi | 89% | 2746 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 61,482 psi | 88% | 2989 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 59,611 psi | 86% | 2831 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,463 psi | 54% | 1713 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 61,177 psi | 88% | 2743 fps | 100% |
| IMR 4350 | <<locked>> | 86% | 60,582 psi | 87% | 2772 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 82% | 59,872 psi | 86% | 2749 fps | 100% |
| IMR 4831 | <<locked>> | 90% | 62,642 psi | 90% | 2785 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 59,799 psi | 86% | 2789 fps | 100% |
| IMR 7828 SSC | <<locked>> | 92% | 62,859 psi | 90% | 2920 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 98% | 62,163 psi | 89% | 2792 fps | 97.2% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 47,993 psi | 69% | 2743 fps | 99.8% |
| Lovex S065 | <<locked>> | 84% | 60,756 psi | 87% | 2743 fps | 100% |
| Lovex S070 | <<locked>> | 86% | 62,758 psi | 90% | 2795 fps | 100% |
| Lovex S071 | <<locked>> | 98% | 61,482 psi | 88% | 2779 fps | 100% |
| Norma 204 | <<locked>> | 86% | 62,265 psi | 89% | 2838 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 48,762 psi | 70% | 2762 fps | 100% |
| Norma MRP | <<locked>> | 90% | 60,713 psi | 87% | 2887 fps | 100% |
| Norma URP | <<locked>> | 86% | 62,903 psi | 90% | 2808 fps | 100% |
| Ramshot Grand | <<locked>> | 88% | 58,740 psi | 84% | 2871 fps | 100% |
| Ramshot Hunter | <<locked>> | 86% | 61,960 psi | 89% | 2828 fps | 100% |
| Ramshot Magnum | <<locked>> | 92% | 60,046 psi | 86% | 2838 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,421 psi | 55% | 1752 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 61,293 psi | 88% | 2805 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 84% | 60,089 psi | 86% | 2838 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 62,685 psi | 90% | 2982 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 61,830 psi | 89% | 2959 fps | 100% |
| Rottweil R 904 | <<locked>> | 90% | 62,613 psi | 90% | 2825 fps | 100% |
| Rottweil R 905 | <<locked>> | 90% | 61,105 psi | 88% | 2838 fps | 100% |
| Rottweil R 907 | <<locked>> | 84% | 62,076 psi | 89% | 2779 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 84% | 60,756 psi | 87% | 2743 fps | 100% |
| Shooters World SW4350 | <<locked>> | 86% | 62,758 psi | 90% | 2795 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 82% | 62,743 psi | 90% | 2615 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 59,683 psi | 86% | 2703 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 60,669 psi | 87% | 2831 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 60,307 psi | 87% | 2769 fps | 100% |
| Somchem S365 | <<locked>> | 86% | 60,394 psi | 87% | 2762 fps | 100% |
| Somchem S385 | <<locked>> | 90% | 61,467 psi | 88% | 2805 fps | 100% |
| Unknown powder | <<locked>> | 84% | 62,917 psi | 90% | 2812 fps | 100% |
| Vihtavuori N150 | <<locked>> | 86% | 61,699 psi | 89% | 2687 fps | 100% |
| Vihtavuori N160 | <<locked>> | 82% | 59,263 psi | 85% | 2730 fps | 100% |
| Vihtavuori N165 | <<locked>> | 94% | 59,219 psi | 85% | 2766 fps | 100% |
| Vihtavuori N170ᴾ | <<locked>> | 100% | 53,925 psi | 77% | 2740 fps | 97.3% |
| Vihtavuori N550 | <<locked>> | 82% | 59,814 psi | 86% | 2776 fps | 100% |
| Vihtavuori N555 | <<locked>> | 90% | 60,060 psi | 86% | 2792 fps | 100% |
| Vihtavuori N560 | <<locked>> | 92% | 60,945 psi | 88% | 2907 fps | 100% |
| Vihtavuori N565 | <<locked>> | 96% | 60,350 psi | 87% | 2881 fps | 100% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 62,076 psi | 89% | 2956 fps | 100% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 59,669 psi | 86% | 2966 fps | 99.3% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 60,437 psi | 87% | 2707 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 94% | 62,381 psi | 90% | 2913 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 88% | 58,885 psi | 85% | 2776 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% | 58,610 psi | 84% | 2690 fps | 100% |
| Accurate 3100 | <<locked>> | 80% | 39,958 psi | 57% | 2464 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 53,200 psi | 76% | 2680 fps | 100% |
| Accurate MAGPRO | <<locked>> | 80% | 39,233 psi | 56% | 2543 fps | 96.5% |
| ADI APS 450 | <<locked>> | 80% | 59,379 psi | 85% | 2110 fps | 100% |
| ADI AR 2209 | <<locked>> | 80% | 44,469 psi | 64% | 2595 fps | 99.7% |
| ADI AR 2213 | <<locked>> | 80% | 39,682 psi | 57% | 2543 fps | 98.3% |
| ADI AR 2217 | <<locked>> | 82% | 31,488 psi | 45% | 2352 fps | 95.8% |
| ADI AR 2218 | <<locked>> | 94% | 40,611 psi | 58% | 2644 fps | 95.3% |
| ADI AR 2225 | <<locked>> | 80% | 26,701 psi | 38% | 2267 fps | 96.7% |
| Alliant Reloder-16 | <<locked>> | 80% | 51,343 psi | 74% | 2690 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 44,324 psi | 64% | 2589 fps | 99.7% |
| Alliant Reloder-22 | <<locked>> | 80% | 40,219 psi | 58% | 2546 fps | 99.2% |
| Alliant Reloder-23 | <<locked>> | 80% | 38,972 psi | 56% | 2487 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 33,605 psi | 48% | 2434 fps | 99.9% |
| Alliant Reloder-26 | <<locked>> | 80% | 43,656 psi | 63% | 2641 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 92% | 41,089 psi | 59% | 2641 fps | 95.9% |
| Alliant Reloder-50 | <<locked>> | 98% | 43,294 psi | 62% | 2684 fps | 96.1% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 38,914 psi | 56% | 2464 fps | 95% |
| Bofors RP15 | <<locked>> | 80% | 37,405 psi | 54% | 2487 fps | 98.6% |
| Bofors RP30 | <<locked>> | 80% | 30,922 psi | 44% | 2365 fps | 96% |
| Bofors RP5 | <<locked>> | 80% | 40,219 psi | 58% | 2546 fps | 99.2% |
| Bofors RP7 | <<locked>> | 80% | 54,810 psi | 79% | 2684 fps | 100% |
| Hodgdon H1000 | <<locked>> | 80% | 30,124 psi | 43% | 2320 fps | 95.9% |
| Hodgdon H4350 | <<locked>> | 80% | 52,417 psi | 75% | 2680 fps | 100% |
| Hodgdon H4831 | <<locked>> | 80% | 37,333 psi | 54% | 2438 fps | 97% |
| Hodgdon H4831 SC | <<locked>> | 80% | 41,524 psi | 60% | 2526 fps | 98.1% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 48,037 psi | 69% | 2566 fps | 100% |
| Hodgdon Retumbo | 83.2 gr | 80% | 32,793 psi | 47% | 2474 fps | 98.3% |
| Hodgdon Superformance | <<locked>> | 80% | 55,376 psi | 80% | 2776 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,166 psi | 40% | 1532 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 57,522 psi | 83% | 2697 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 50,212 psi | 72% | 2628 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 80% | 56,159 psi | 81% | 2700 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 45,745 psi | 66% | 2556 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 43,627 psi | 63% | 2533 fps | 98.6% |
| IMR 7828 SSC | <<locked>> | 80% | 40,988 psi | 59% | 2575 fps | 98.6% |
| IMR 7977 Enduron | <<locked>> | 92% | 51,242 psi | 74% | 2631 fps | 95% |
| IMR 8133 Enduron | <<locked>> | 86% | 29,660 psi | 43% | 2352 fps | 95.1% |
| Lovex S065 | <<locked>> | 80% | 53,592 psi | 77% | 2648 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 52,011 psi | 75% | 2651 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 34,360 psi | 49% | 2352 fps | 99.5% |
| Norma 204 | <<locked>> | 80% | 50,807 psi | 73% | 2680 fps | 100% |
| Norma 217 | <<locked>> | 82% | 25,889 psi | 37% | 2264 fps | 95.6% |
| Norma MRP | <<locked>> | 80% | 42,554 psi | 61% | 2612 fps | 100% |
| Norma URP | <<locked>> | 80% | 51,851 psi | 74% | 2667 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 42,975 psi | 62% | 2628 fps | 99.3% |
| Ramshot Hunter | <<locked>> | 80% | 50,749 psi | 73% | 2677 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 37,536 psi | 54% | 2490 fps | 99.4% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,819 psi | 41% | 1568 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 53,519 psi | 77% | 2707 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 52,011 psi | 75% | 2733 fps | 100% |
| ReloadSwiss RS 76 | 89 gr | 80% | 31,720 psi | 46% | 2444 fps | 98.9% |
| ReloadSwiss RS 80 | <<locked>> | 84% | 33,315 psi | 48% | 2461 fps | 95.3% |
| Rottweil R 904 | <<locked>> | 80% | 45,353 psi | 65% | 2569 fps | 99.2% |
| Rottweil R 905 | <<locked>> | 80% | 43,830 psi | 63% | 2575 fps | 99.7% |
| Rottweil R 907 | <<locked>> | 80% | 54,810 psi | 79% | 2684 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 80% | 53,592 psi | 77% | 2648 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 52,011 psi | 75% | 2651 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 58,958 psi | 85% | 2572 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 52,460 psi | 75% | 2608 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 43,497 psi | 62% | 2572 fps | 99.6% |
| Somchem S361 | <<locked>> | 80% | 46,137 psi | 66% | 2559 fps | 98.9% |
| Somchem S365 | <<locked>> | 80% | 49,472 psi | 71% | 2621 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 44,179 psi | 63% | 2552 fps | 99.9% |
| Unknown powder | <<locked>> | 80% | 55,288 psi | 79% | 2713 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 51,256 psi | 74% | 2556 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 55,492 psi | 80% | 2680 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 37,376 psi | 54% | 2415 fps | 99% |
| Vihtavuori N170 | <<locked>> | 94% | 44,309 psi | 64% | 2575 fps | 95% |
| Vihtavuori N550 | <<locked>> | 80% | 56,072 psi | 81% | 2726 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 43,337 psi | 62% | 2556 fps | 100% |
| Vihtavuori N560 | 84.5 gr | 80% | 40,350 psi | 58% | 2569 fps | 98% |
| Vihtavuori N565 | <<locked>> | 80% | 34,853 psi | 50% | 2438 fps | 96.6% |
| Vihtavuori N568 | <<locked>> | 84% | 34,838 psi | 50% | 2480 fps | 95.3% |
| Vihtavuori N570 | <<locked>> | 90% | 41,307 psi | 59% | 2651 fps | 95.5% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 52,591 psi | 76% | 2612 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 36,390 psi | 52% | 2539 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 44,280 psi | 64% | 2556 fps | 99.7% |
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 | 265gr | Barnes TAC-TX BT. Hodgdon Retumbo delivers the highest muzzle velocity at 2,989 fps; across all powders the maximum-charge window runs from 1,713 fps to 2,989 fps. Accurate 8700 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 265.0 gr projectile in 0.338" calls for a 1:10.5 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 N560 rank at the top here: for .338 Lapua Mag. Ackley Improved with the .338 | 265gr | Barnes TAC-TX BT they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Accurate 8700, Ramshot LRT, SNPE Vectan SP 13 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.