Load Specifications
Load data in caliber .338 Lapua Mag. Ackley Improved with .338 | 290gr | Peregrine Glider GRM bullet and 81 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 N570.
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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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>> | 92% | 61,598 psi | 88% | 2654 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 62,468 psi | 90% | 2664 fps | 100% |
| Accurate MAGPRO | <<locked>> | 92% | 61,902 psi | 89% | 2792 fps | 100% |
| ADI APS 450 | <<locked>> | 82% | 61,409 psi | 88% | 2028 fps | 100% |
| ADI AR 2209 | <<locked>> | 88% | 59,596 psi | 86% | 2697 fps | 100% |
| ADI AR 2213 | <<locked>> | 92% | 61,931 psi | 89% | 2769 fps | 100% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 60,162 psi | 86% | 2746 fps | 100% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 52,040 psi | 75% | 2762 fps | 99.2% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 54,360 psi | 78% | 2717 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 88% | 59,712 psi | 86% | 2694 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 84% | 59,828 psi | 86% | 2667 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 90% | 62,758 psi | 90% | 2733 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 92% | 61,975 psi | 89% | 2759 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 92% | 59,640 psi | 86% | 2654 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 96% | 60,017 psi | 86% | 2733 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 88% | 60,843 psi | 87% | 2753 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 57,377 psi | 82% | 2799 fps | 99.6% |
| Alliant Reloder-50ᴾ | <<locked>> | 100% | 48,327 psi | 69% | 2667 fps | 98.1% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 62,047 psi | 89% | 2736 fps | 99.8% |
| Bofors RP15 | <<locked>> | 94% | 61,061 psi | 88% | 2746 fps | 100% |
| Bofors RP30 | <<locked>> | 98% | 59,350 psi | 85% | 2759 fps | 100% |
| Bofors RP5 | <<locked>> | 92% | 61,975 psi | 89% | 2759 fps | 100% |
| Bofors RP7 | <<locked>> | 82% | 59,495 psi | 85% | 2618 fps | 100% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 61,946 psi | 89% | 2762 fps | 100% |
| Hodgdon H4350 | <<locked>> | 84% | 60,756 psi | 87% | 2667 fps | 100% |
| Hodgdon H4831 | <<locked>> | 94% | 60,568 psi | 87% | 2700 fps | 100% |
| Hodgdon H4831 SC | <<locked>> | 90% | 59,756 psi | 86% | 2694 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 59,814 psi | 86% | 2589 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 96% | 59,059 psi | 85% | 2825 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 61,032 psi | 88% | 2720 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,623 psi | 54% | 1624 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 62,323 psi | 90% | 2628 fps | 100% |
| IMR 4350 | <<locked>> | 86% | 61,873 psi | 89% | 2661 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 82% | 61,061 psi | 88% | 2635 fps | 100% |
| IMR 4831 | <<locked>> | 88% | 60,336 psi | 87% | 2628 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 61,221 psi | 88% | 2680 fps | 100% |
| IMR 7828 SSC | <<locked>> | 90% | 60,234 psi | 87% | 2756 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 96% | 59,495 psi | 85% | 2638 fps | 97.4% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 49,647 psi | 71% | 2648 fps | 100% |
| Lovex D100ᴾ | <<locked>> | 100% | 59,495 psi | 85% | 2687 fps | 96.5% |
| Lovex S065 | <<locked>> | 84% | 61,917 psi | 89% | 2628 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 60,307 psi | 87% | 2635 fps | 100% |
| Lovex S071 | <<locked>> | 96% | 59,176 psi | 85% | 2625 fps | 100% |
| Norma 204 | <<locked>> | 84% | 59,553 psi | 86% | 2677 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 50,401 psi | 72% | 2664 fps | 100% |
| Norma MRP | <<locked>> | 90% | 62,294 psi | 89% | 2772 fps | 100% |
| Norma URP | <<locked>> | 84% | 60,423 psi | 87% | 2648 fps | 100% |
| Ramshot Grand | <<locked>> | 88% | 60,582 psi | 87% | 2762 fps | 100% |
| Ramshot Hunter | <<locked>> | 84% | 59,364 psi | 85% | 2667 fps | 100% |
| Ramshot Magnum | <<locked>> | 92% | 61,714 psi | 89% | 2730 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,493 psi | 55% | 1663 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 62,845 psi | 90% | 2694 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 84% | 61,627 psi | 89% | 2723 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 59,988 psi | 86% | 2818 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 59,030 psi | 85% | 2802 fps | 100% |
| Rottweil R 904 | <<locked>> | 88% | 60,031 psi | 86% | 2664 fps | 100% |
| Rottweil R 905 | <<locked>> | 90% | 62,743 psi | 90% | 2726 fps | 100% |
| Rottweil R 907 | <<locked>> | 82% | 59,495 psi | 85% | 2618 fps | 100% |
| Shooters World 50 BMGᴾ | <<locked>> | 100% | 59,495 psi | 85% | 2687 fps | 96.5% |
| Shooters World Long Rifle | <<locked>> | 84% | 61,917 psi | 89% | 2628 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 60,307 psi | 87% | 2635 fps | 100% |
| SNPE Vectan SP 13ᴾ | <<locked>> | 100% | 42,772 psi | 61% | 2493 fps | 96.2% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 60,974 psi | 88% | 2592 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 62,323 psi | 90% | 2723 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 61,540 psi | 88% | 2661 fps | 100% |
| Somchem S365 | <<locked>> | 86% | 61,960 psi | 89% | 2648 fps | 100% |
| Somchem S385 | <<locked>> | 90% | 62,801 psi | 90% | 2690 fps | 100% |
| Unknown powder | <<locked>> | 82% | 60,350 psi | 87% | 2648 fps | 100% |
| Vihtavuori N150 | <<locked>> | 86% | 62,961 psi | 90% | 2572 fps | 100% |
| Vihtavuori N160 | <<locked>> | 82% | 60,640 psi | 87% | 2615 fps | 100% |
| Vihtavuori N165 | <<locked>> | 94% | 60,713 psi | 87% | 2657 fps | 100% |
| Vihtavuori N170ᴾ | <<locked>> | 100% | 55,303 psi | 79% | 2641 fps | 98.2% |
| Vihtavuori N550 | <<locked>> | 82% | 61,221 psi | 88% | 2661 fps | 100% |
| Vihtavuori N555 | <<locked>> | 90% | 61,685 psi | 89% | 2680 fps | 100% |
| Vihtavuori N560 | <<locked>> | 92% | 62,497 psi | 90% | 2799 fps | 100% |
| Vihtavuori N565 | <<locked>> | 96% | 62,163 psi | 89% | 2776 fps | 100% |
| Vihtavuori N568 | <<locked>> | 98% | 59,553 psi | 86% | 2795 fps | 100% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 61,496 psi | 88% | 2864 fps | 99.7% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 61,627 psi | 89% | 2592 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 92% | 59,872 psi | 86% | 2749 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 88% | 60,379 psi | 87% | 2667 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% | 41,205 psi | 59% | 2375 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 54,665 psi | 79% | 2572 fps | 100% |
| Accurate MAGPRO | <<locked>> | 80% | 40,379 psi | 58% | 2457 fps | 97.6% |
| ADI APS 450 | <<locked>> | 80% | 59,263 psi | 85% | 2001 fps | 100% |
| ADI AR 2209 | <<locked>> | 80% | 45,556 psi | 65% | 2497 fps | 99.9% |
| ADI AR 2213 | <<locked>> | 80% | 40,785 psi | 59% | 2451 fps | 99.1% |
| ADI AR 2217 | <<locked>> | 80% | 30,226 psi | 43% | 2221 fps | 96.3% |
| ADI AR 2218 | <<locked>> | 92% | 38,812 psi | 56% | 2503 fps | 95.7% |
| ADI AR 2225 | <<locked>> | 80% | 27,499 psi | 40% | 2198 fps | 98.2% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 45,992 psi | 66% | 2497 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 52,591 psi | 76% | 2575 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 45,542 psi | 65% | 2493 fps | 99.9% |
| Alliant Reloder-22 | <<locked>> | 80% | 41,365 psi | 59% | 2454 fps | 99.7% |
| Alliant Reloder-23 | <<locked>> | 80% | 40,118 psi | 58% | 2388 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 34,563 psi | 50% | 2349 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 80% | 45,165 psi | 65% | 2546 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 88% | 36,477 psi | 52% | 2438 fps | 95.2% |
| Alliant Reloder-50 | <<locked>> | 94% | 38,508 psi | 55% | 2484 fps | 95.4% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 39,827 psi | 57% | 2379 fps | 96.3% |
| Bofors RP15 | <<locked>> | 80% | 38,522 psi | 55% | 2402 fps | 99.3% |
| Bofors RP30 | <<locked>> | 80% | 32,068 psi | 46% | 2290 fps | 97.3% |
| Bofors RP5 | <<locked>> | 80% | 41,365 psi | 59% | 2454 fps | 99.7% |
| Bofors RP7 | <<locked>> | 80% | 55,941 psi | 80% | 2572 fps | 100% |
| Hodgdon H1000 | <<locked>> | 80% | 31,009 psi | 45% | 2244 fps | 97.3% |
| Hodgdon H4350 | <<locked>> | 80% | 53,577 psi | 77% | 2572 fps | 100% |
| Hodgdon H4831 | <<locked>> | 80% | 38,261 psi | 55% | 2352 fps | 98% |
| Hodgdon H4831 SC | <<locked>> | 80% | 42,598 psi | 61% | 2434 fps | 98.9% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 49,356 psi | 71% | 2464 fps | 100% |
| Hodgdon Retumbo | 79.5 gr | 80% | 33,808 psi | 49% | 2395 fps | 99.3% |
| Hodgdon Superformance | <<locked>> | 80% | 56,898 psi | 82% | 2667 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,166 psi | 40% | 1450 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 58,668 psi | 84% | 2582 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 51,256 psi | 74% | 2523 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 80% | 57,319 psi | 82% | 2589 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 46,905 psi | 67% | 2454 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 44,556 psi | 64% | 2434 fps | 99.2% |
| IMR 7828 SSC | <<locked>> | 80% | 42,134 psi | 61% | 2487 fps | 99.3% |
| IMR 7977 Enduron | <<locked>> | 90% | 49,153 psi | 71% | 2487 fps | 95.3% |
| IMR 8133 Enduron | <<locked>> | 84% | 28,601 psi | 41% | 2228 fps | 95.7% |
| Lovex D100 | <<locked>> | 98% | 55,376 psi | 80% | 2631 fps | 95.7% |
| Lovex S065 | <<locked>> | 80% | 54,694 psi | 79% | 2539 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 53,200 psi | 76% | 2543 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 35,462 psi | 51% | 2270 fps | 99.9% |
| Norma 204 | <<locked>> | 80% | 51,967 psi | 75% | 2575 fps | 100% |
| Norma 217 | <<locked>> | 80% | 25,019 psi | 36% | 2146 fps | 96.2% |
| Norma MRP | <<locked>> | 80% | 43,845 psi | 63% | 2516 fps | 100% |
| Norma URP | <<locked>> | 80% | 53,142 psi | 76% | 2559 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 44,440 psi | 64% | 2536 fps | 99.8% |
| Ramshot Hunter | <<locked>> | 80% | 51,982 psi | 75% | 2569 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 38,754 psi | 56% | 2405 fps | 99.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,993 psi | 42% | 1486 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 54,766 psi | 79% | 2595 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 53,432 psi | 77% | 2625 fps | 100% |
| ReloadSwiss RS 76 | 85.1 gr | 80% | 32,808 psi | 47% | 2369 fps | 99.7% |
| ReloadSwiss RS 80 | <<locked>> | 82% | 31,952 psi | 46% | 2326 fps | 95.7% |
| Rottweil R 904 | <<locked>> | 80% | 46,441 psi | 67% | 2470 fps | 99.7% |
| Rottweil R 905 | <<locked>> | 80% | 45,078 psi | 65% | 2480 fps | 100% |
| Rottweil R 907 | <<locked>> | 80% | 55,941 psi | 80% | 2572 fps | 100% |
| Shooters World 50 BMG | <<locked>> | 98% | 55,376 psi | 80% | 2631 fps | 95.7% |
| Shooters World Long Rifle | <<locked>> | 80% | 54,694 psi | 79% | 2539 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 53,200 psi | 76% | 2543 fps | 100% |
| SNPE Vectan SP 13 | <<locked>> | 98% | 39,900 psi | 57% | 2438 fps | 95.2% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 53,505 psi | 77% | 2500 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 44,744 psi | 64% | 2477 fps | 99.9% |
| Somchem S361 | <<locked>> | 80% | 47,224 psi | 68% | 2464 fps | 99.4% |
| Somchem S365 | <<locked>> | 80% | 50,734 psi | 73% | 2513 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 45,295 psi | 65% | 2454 fps | 100% |
| Unknown powder | <<locked>> | 80% | 56,724 psi | 81% | 2605 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 52,460 psi | 75% | 2448 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 56,811 psi | 82% | 2572 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 38,392 psi | 55% | 2329 fps | 99.6% |
| Vihtavuori N170 | <<locked>> | 92% | 42,641 psi | 61% | 2438 fps | 95.4% |
| Vihtavuori N550 | <<locked>> | 80% | 57,392 psi | 82% | 2615 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 44,570 psi | 64% | 2454 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 41,582 psi | 60% | 2480 fps | 98.9% |
| Vihtavuori N565 | <<locked>> | 80% | 35,911 psi | 52% | 2356 fps | 97.8% |
| Vihtavuori N568 | <<locked>> | 82% | 33,460 psi | 48% | 2346 fps | 95.7% |
| Vihtavuori N570 | 91.7 gr | 88% | 39,697 psi | 57% | 2510 fps | 95.9% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 53,882 psi | 77% | 2503 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 37,840 psi | 54% | 2448 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 45,513 psi | 65% | 2464 fps | 99.9% |
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 81 powders for .338 Lapua Mag. Ackley Improved loaded with the .338 | 290gr | Peregrine Glider GRM. Vihtavuori N570 delivers the highest muzzle velocity at 2,864 fps; across all powders the maximum-charge window runs from 1,624 fps to 2,864 fps. ADI AR 2217 gives the best case fill at 100 %, and 81 of the 81 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 290.0 gr projectile in 0.338" calls for a 1:9.0 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 N570 rank at the top here: for .338 Lapua Mag. Ackley Improved with the .338 | 290gr | Peregrine Glider GRM 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.