Load Specifications
Load data in caliber .338 Lapua Mag. Ackley Improved with .338 | 252gr | CutEdge MTH bullet and 85 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 2700 | <<locked>> | 82% | 61,119 psi | 88% | 2789 fps | 100% |
| Accurate 3100 | <<locked>> | 94% | 62,337 psi | 90% | 2858 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 59,234 psi | 85% | 2828 fps | 100% |
| Accurate MAGPRO | <<locked>> | 94% | 62,526 psi | 90% | 2995 fps | 99.8% |
| ADI APS 450 | <<locked>> | 82% | 61,293 psi | 88% | 2192 fps | 100% |
| ADI AR 2208 | <<locked>> | 82% | 62,801 psi | 90% | 2822 fps | 100% |
| ADI AR 2209 | <<locked>> | 90% | 60,321 psi | 87% | 2904 fps | 100% |
| ADI AR 2213 | <<locked>> | 94% | 62,700 psi | 90% | 2979 fps | 100% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 56,550 psi | 81% | 2894 fps | 100% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 48,863 psi | 70% | 2874 fps | 97.4% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 50,865 psi | 73% | 2861 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 86% | 60,539 psi | 87% | 2881 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 82% | 61,888 psi | 89% | 2890 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 90% | 59,799 psi | 86% | 2894 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 94% | 62,671 psi | 90% | 2966 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 94% | 60,162 psi | 86% | 2861 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 98% | 60,307 psi | 87% | 2940 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 90% | 61,380 psi | 88% | 2963 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 53,606 psi | 77% | 2930 fps | 98.4% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 59,292 psi | 85% | 2887 fps | 99.1% |
| Bofors RP15 | <<locked>> | 96% | 61,496 psi | 88% | 2953 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 59,756 psi | 86% | 2959 fps | 100% |
| Bofors RP5 | <<locked>> | 94% | 62,671 psi | 90% | 2966 fps | 100% |
| Bofors RP7 | <<locked>> | 84% | 60,742 psi | 87% | 2828 fps | 100% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 58,189 psi | 84% | 2913 fps | 100% |
| Hodgdon H414 | <<locked>> | 82% | 61,888 psi | 89% | 2900 fps | 100% |
| Hodgdon H4350 | <<locked>> | 86% | 61,656 psi | 89% | 2877 fps | 100% |
| Hodgdon H4831 | <<locked>> | 96% | 61,293 psi | 88% | 2904 fps | 100% |
| Hodgdon H4831 SC | <<locked>> | 92% | 60,727 psi | 87% | 2897 fps | 99.9% |
| Hodgdon Hybrid 100V | <<locked>> | 88% | 60,640 psi | 87% | 2799 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 59,219 psi | 85% | 3031 fps | 100% |
| Hodgdon Superformance | <<locked>> | 84% | 62,192 psi | 89% | 2933 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,449 psi | 54% | 1759 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 61,844 psi | 89% | 2795 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 59,857 psi | 86% | 2795 fps | 100% |
| IMR 4350 | <<locked>> | 86% | 59,146 psi | 85% | 2822 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 84% | 62,091 psi | 89% | 2848 fps | 100% |
| IMR 4831 | <<locked>> | 90% | 61,032 psi | 88% | 2838 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 92% | 62,120 psi | 89% | 2884 fps | 100% |
| IMR 7828 SSC | <<locked>> | 92% | 60,930 psi | 88% | 2963 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 98% | 60,640 psi | 87% | 2831 fps | 96.4% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 46,180 psi | 66% | 2776 fps | 99.5% |
| Lovex S065 | <<locked>> | 86% | 62,946 psi | 90% | 2838 fps | 100% |
| Lovex S070 | <<locked>> | 86% | 61,293 psi | 88% | 2844 fps | 100% |
| Lovex S071 | <<locked>> | 98% | 59,785 psi | 86% | 2828 fps | 100% |
| Norma 204 | <<locked>> | 86% | 60,611 psi | 87% | 2887 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 46,775 psi | 67% | 2799 fps | 100% |
| Norma MRP | <<locked>> | 92% | 62,975 psi | 90% | 2986 fps | 100% |
| Norma URP | <<locked>> | 86% | 61,293 psi | 88% | 2861 fps | 100% |
| Ramshot Grand | <<locked>> | 90% | 61,250 psi | 88% | 2972 fps | 100% |
| Ramshot Hunter | <<locked>> | 86% | 60,278 psi | 87% | 2877 fps | 100% |
| Ramshot Magnum | <<locked>> | 94% | 62,714 psi | 90% | 2940 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,363 psi | 55% | 1801 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 59,538 psi | 86% | 2854 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 86% | 62,482 psi | 90% | 2940 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 60,292 psi | 87% | 3025 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 59,495 psi | 85% | 2999 fps | 99.9% |
| Rottweil R 903 | <<locked>> | 82% | 62,555 psi | 90% | 2812 fps | 100% |
| Rottweil R 904 | <<locked>> | 90% | 61,017 psi | 88% | 2871 fps | 100% |
| Rottweil R 905 | <<locked>> | 90% | 59,335 psi | 85% | 2884 fps | 100% |
| Rottweil R 907 | <<locked>> | 84% | 60,742 psi | 87% | 2828 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 86% | 62,946 psi | 90% | 2838 fps | 100% |
| Shooters World SW4350 | <<locked>> | 86% | 61,293 psi | 88% | 2844 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 82% | 61,467 psi | 88% | 2667 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 62,279 psi | 89% | 2802 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 58,914 psi | 85% | 2881 fps | 100% |
| Somchem S355 | <<locked>> | 82% | 61,699 psi | 89% | 2802 fps | 100% |
| Somchem S361 | <<locked>> | 90% | 62,845 psi | 90% | 2867 fps | 100% |
| Somchem S365 | <<locked>> | 88% | 62,743 psi | 90% | 2858 fps | 100% |
| Somchem S385 | <<locked>> | 90% | 59,741 psi | 86% | 2851 fps | 100% |
| Unknown powder | <<locked>> | 84% | 61,380 psi | 88% | 2864 fps | 100% |
| Vihtavuori N150 | <<locked>> | 86% | 60,205 psi | 86% | 2740 fps | 100% |
| Vihtavuori N160 | <<locked>> | 84% | 61,685 psi | 89% | 2828 fps | 100% |
| Vihtavuori N165 | <<locked>> | 96% | 61,380 psi | 88% | 2858 fps | 100% |
| Vihtavuori N170ᴾ | <<locked>> | 100% | 52,286 psi | 75% | 2772 fps | 96.5% |
| Vihtavuori N550 | <<locked>> | 84% | 62,236 psi | 89% | 2874 fps | 100% |
| Vihtavuori N555 | <<locked>> | 92% | 62,250 psi | 89% | 2890 fps | 100% |
| Vihtavuori N560 | <<locked>> | 92% | 58,972 psi | 85% | 2949 fps | 100% |
| Vihtavuori N565 | <<locked>> | 98% | 62,656 psi | 90% | 2979 fps | 100% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 59,959 psi | 86% | 2995 fps | 99.8% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 57,508 psi | 83% | 3002 fps | 98.7% |
| Winchester 6.5 StaBALL | <<locked>> | 86% | 62,859 psi | 90% | 2802 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 61,888 psi | 89% | 2900 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 94% | 59,741 psi | 86% | 2956 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 90% | 61,554 psi | 88% | 2874 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% | 57,348 psi | 82% | 2740 fps | 100% |
| Accurate 3100 | <<locked>> | 80% | 38,682 psi | 56% | 2503 fps | 99.8% |
| Accurate 4350 | <<locked>> | 80% | 51,619 psi | 74% | 2726 fps | 100% |
| Accurate MAGPRO | <<locked>> | 80% | 37,927 psi | 54% | 2572 fps | 95.5% |
| ADI APS 450 | <<locked>> | 80% | 59,263 psi | 85% | 2162 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 59,103 psi | 85% | 2776 fps | 100% |
| ADI AR 2209 | <<locked>> | 80% | 43,149 psi | 62% | 2635 fps | 99.3% |
| ADI AR 2213 | <<locked>> | 80% | 38,421 psi | 55% | 2572 fps | 97.4% |
| ADI AR 2217 | <<locked>> | 84% | 32,532 psi | 47% | 2434 fps | 95.6% |
| ADI AR 2218 | <<locked>> | 96% | 42,279 psi | 61% | 2736 fps | 95.2% |
| ADI AR 2225 | <<locked>> | 80% | 25,831 psi | 37% | 2283 fps | 95.4% |
| Alliant Reloder-16 | <<locked>> | 80% | 49,647 psi | 71% | 2733 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 80% | 57,696 psi | 83% | 2841 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 43,047 psi | 62% | 2625 fps | 99.3% |
| Alliant Reloder-22 | <<locked>> | 80% | 38,870 psi | 56% | 2579 fps | 98.7% |
| Alliant Reloder-23 | <<locked>> | 80% | 37,637 psi | 54% | 2523 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 32,430 psi | 47% | 2464 fps | 99.5% |
| Alliant Reloder-26 | <<locked>> | 80% | 42,061 psi | 60% | 2680 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 94% | 42,627 psi | 61% | 2730 fps | 95.8% |
| Baschieri & Pellagri 109 | <<locked>> | 82% | 40,509 psi | 58% | 2552 fps | 95% |
| Bofors RP15 | <<locked>> | 80% | 36,158 psi | 52% | 2516 fps | 97.9% |
| Bofors RP30 | <<locked>> | 82% | 31,952 psi | 46% | 2448 fps | 95.8% |
| Bofors RP5 | <<locked>> | 80% | 38,870 psi | 56% | 2579 fps | 98.7% |
| Bofors RP7 | <<locked>> | 80% | 53,519 psi | 77% | 2730 fps | 100% |
| Hodgdon H1000 | <<locked>> | 82% | 31,270 psi | 45% | 2402 fps | 95.7% |
| Hodgdon H414 | <<locked>> | 80% | 57,827 psi | 83% | 2848 fps | 100% |
| Hodgdon H4350 | <<locked>> | 80% | 51,097 psi | 73% | 2726 fps | 100% |
| Hodgdon H4831 | <<locked>> | 80% | 36,230 psi | 52% | 2470 fps | 96% |
| Hodgdon H4831 SC | <<locked>> | 80% | 40,263 psi | 58% | 2559 fps | 97.3% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 46,688 psi | 67% | 2612 fps | 100% |
| Hodgdon Retumbo | 84 gr | 80% | 31,633 psi | 45% | 2493 fps | 97.3% |
| Hodgdon Superformance | <<locked>> | 80% | 53,708 psi | 77% | 2818 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,978 psi | 40% | 1568 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 58,146 psi | 84% | 2749 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 56,318 psi | 81% | 2746 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 48,936 psi | 70% | 2674 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 80% | 54,868 psi | 79% | 2749 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 44,483 psi | 64% | 2602 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 42,467 psi | 61% | 2572 fps | 98% |
| IMR 7828 SSC | <<locked>> | 80% | 39,581 psi | 57% | 2608 fps | 97.9% |
| IMR 7977 Enduron | <<locked>> | 96% | 56,782 psi | 82% | 2776 fps | 95.7% |
| IMR 8133 Enduron | <<locked>> | 90% | 32,692 psi | 47% | 2487 fps | 96% |
| Lovex S065 | <<locked>> | 80% | 52,315 psi | 75% | 2697 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 50,676 psi | 73% | 2697 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 33,243 psi | 48% | 2385 fps | 99.1% |
| Norma 204 | <<locked>> | 80% | 49,327 psi | 71% | 2720 fps | 99.8% |
| Norma 217 | <<locked>> | 84% | 26,672 psi | 38% | 2339 fps | 95.3% |
| Norma MRP | <<locked>> | 80% | 41,133 psi | 59% | 2648 fps | 99.8% |
| Norma URP | <<locked>> | 80% | 50,415 psi | 72% | 2713 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 41,495 psi | 60% | 2661 fps | 98.7% |
| Ramshot Hunter | <<locked>> | 80% | 49,284 psi | 71% | 2720 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 36,172 psi | 52% | 2520 fps | 98.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,718 psi | 41% | 1608 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 51,851 psi | 74% | 2753 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 50,401 psi | 72% | 2779 fps | 100% |
| ReloadSwiss RS 76 | 89.9 gr | 80% | 30,632 psi | 44% | 2467 fps | 98% |
| ReloadSwiss RS 80 | <<locked>> | 86% | 34,548 psi | 50% | 2546 fps | 95.2% |
| Rottweil R 903 | <<locked>> | 80% | 58,595 psi | 84% | 2762 fps | 100% |
| Rottweil R 904 | <<locked>> | 80% | 44,135 psi | 63% | 2608 fps | 98.7% |
| Rottweil R 905 | <<locked>> | 80% | 42,496 psi | 61% | 2615 fps | 99.3% |
| Rottweil R 907 | <<locked>> | 80% | 53,519 psi | 77% | 2730 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 80% | 52,315 psi | 75% | 2697 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 50,676 psi | 73% | 2697 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 57,783 psi | 83% | 2625 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 51,169 psi | 74% | 2654 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 42,163 psi | 61% | 2612 fps | 99.2% |
| Somchem S355 | <<locked>> | 80% | 58,044 psi | 83% | 2756 fps | 100% |
| Somchem S361 | <<locked>> | 80% | 44,976 psi | 65% | 2598 fps | 98.3% |
| Somchem S365 | <<locked>> | 80% | 47,906 psi | 69% | 2667 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 42,844 psi | 62% | 2592 fps | 99.7% |
| Unknown powder | <<locked>> | 80% | 53,809 psi | 77% | 2762 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 50,053 psi | 72% | 2608 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 53,940 psi | 77% | 2726 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 36,216 psi | 52% | 2451 fps | 98.4% |
| Vihtavuori N170 | <<locked>> | 98% | 48,950 psi | 70% | 2717 fps | 95.7% |
| Vihtavuori N550 | <<locked>> | 80% | 54,534 psi | 78% | 2776 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 41,930 psi | 60% | 2595 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 38,957 psi | 56% | 2598 fps | 97.2% |
| Vihtavuori N565 | <<locked>> | 80% | 33,591 psi | 48% | 2464 fps | 95.6% |
| Vihtavuori N568 | <<locked>> | 86% | 36,056 psi | 52% | 2566 fps | 95.1% |
| Vihtavuori N570 | <<locked>> | 92% | 42,801 psi | 61% | 2743 fps | 95.4% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 51,198 psi | 74% | 2657 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 57,827 psi | 83% | 2848 fps | 100% |
| Winchester StaBALL HD | 86.2 gr | 80% | 34,664 psi | 50% | 2572 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 43,004 psi | 62% | 2595 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 92 powders for .338 Lapua Mag. Ackley Improved loaded with the .338 | 252gr | CutEdge MTH. Hodgdon Retumbo delivers the highest muzzle velocity at 3,031 fps; across all powders the maximum-charge window runs from 1,759 fps to 3,031 fps. Accurate 8700 gives the best case fill at 100 %, and 92 of the 92 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 252.0 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, Winchester StaBALL HD rank at the top here: for .338 Lapua Mag. Ackley Improved with the .338 | 252gr | CutEdge MTH 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.