Load Specifications
Load data in caliber .338 Lapua Mag. Ackley Improved with .338 | 300gr | CutEdge MTH 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>> | 90% | 59,495 psi | 85% | 2585 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 59,988 psi | 86% | 2592 fps | 100% |
| Accurate 8700ᴾ | <<locked>> | 100% | 42,366 psi | 61% | 2470 fps | 96.9% |
| Accurate MAGPRO | <<locked>> | 90% | 59,567 psi | 86% | 2720 fps | 100% |
| ADI APS 450 | <<locked>> | 82% | 61,366 psi | 88% | 1995 fps | 100% |
| ADI AR 2209 | <<locked>> | 88% | 61,206 psi | 88% | 2674 fps | 100% |
| ADI AR 2213 | <<locked>> | 90% | 59,553 psi | 86% | 2697 fps | 100% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 62,163 psi | 89% | 2726 fps | 100% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 53,838 psi | 77% | 2753 fps | 99.7% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 56,333 psi | 81% | 2697 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 88% | 61,322 psi | 88% | 2671 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 84% | 61,670 psi | 89% | 2641 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 60,597 psi | 87% | 2664 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 90% | 59,712 psi | 86% | 2687 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 92% | 61,670 psi | 89% | 2631 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 96% | 61,989 psi | 89% | 2710 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 88% | 62,903 psi | 90% | 2730 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 59,524 psi | 86% | 2785 fps | 99.9% |
| Alliant Reloder-50ᴾ | <<locked>> | 100% | 50,328 psi | 72% | 2657 fps | 98.8% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 59,828 psi | 86% | 2667 fps | 99.8% |
| Bofors RP15 | <<locked>> | 94% | 62,830 psi | 90% | 2723 fps | 100% |
| Bofors RP30 | <<locked>> | 98% | 61,525 psi | 88% | 2740 fps | 100% |
| Bofors RP5 | <<locked>> | 90% | 59,712 psi | 86% | 2687 fps | 100% |
| Bofors RP7 | <<locked>> | 82% | 60,843 psi | 87% | 2592 fps | 100% |
| Hodgdon H1000 | <<locked>> | 98% | 59,596 psi | 86% | 2694 fps | 100% |
| Hodgdon H4350 | <<locked>> | 84% | 62,221 psi | 89% | 2641 fps | 100% |
| Hodgdon H4831 | <<locked>> | 94% | 62,207 psi | 89% | 2677 fps | 100% |
| Hodgdon H4831 SC | <<locked>> | 90% | 61,366 psi | 88% | 2671 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 61,409 psi | 88% | 2562 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 96% | 61,279 psi | 88% | 2805 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 62,975 psi | 90% | 2697 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,652 psi | 54% | 1598 fps | 100% |
| IMR 4350 | <<locked>> | 84% | 59,669 psi | 86% | 2589 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 82% | 62,395 psi | 90% | 2608 fps | 100% |
| IMR 4831 | <<locked>> | 88% | 61,917 psi | 89% | 2602 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 62,685 psi | 90% | 2657 fps | 100% |
| IMR 7828 SSC | <<locked>> | 90% | 62,134 psi | 89% | 2733 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 96% | 61,148 psi | 88% | 2621 fps | 98% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 51,488 psi | 74% | 2635 fps | 100% |
| Lovex D100ᴾ | <<locked>> | 100% | 61,511 psi | 88% | 2674 fps | 97.3% |
| Lovex S065 | <<locked>> | 82% | 59,640 psi | 86% | 2559 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 61,743 psi | 89% | 2608 fps | 100% |
| Lovex S071 | <<locked>> | 96% | 60,887 psi | 87% | 2602 fps | 100% |
| Norma 204 | <<locked>> | 84% | 61,105 psi | 88% | 2651 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 52,402 psi | 75% | 2648 fps | 100% |
| Norma MRP | <<locked>> | 88% | 60,046 psi | 86% | 2703 fps | 100% |
| Norma URP | <<locked>> | 84% | 61,975 psi | 89% | 2621 fps | 100% |
| Ramshot Grand | <<locked>> | 88% | 62,627 psi | 90% | 2743 fps | 100% |
| Ramshot Hunter | <<locked>> | 84% | 60,930 psi | 88% | 2641 fps | 100% |
| Ramshot Magnum | <<locked>> | 90% | 59,205 psi | 85% | 2657 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,696 psi | 56% | 1637 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 60,350 psi | 87% | 2618 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 82% | 59,161 psi | 85% | 2651 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 62,395 psi | 90% | 2799 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 61,235 psi | 88% | 2782 fps | 100% |
| Rottweil R 904 | <<locked>> | 88% | 61,554 psi | 88% | 2641 fps | 100% |
| Rottweil R 905 | <<locked>> | 88% | 60,321 psi | 87% | 2654 fps | 100% |
| Rottweil R 907 | <<locked>> | 82% | 60,843 psi | 87% | 2592 fps | 100% |
| Shooters World 50 BMGᴾ | <<locked>> | 100% | 61,511 psi | 88% | 2674 fps | 97.3% |
| Shooters World Long Rifle | <<locked>> | 82% | 59,640 psi | 86% | 2559 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 61,743 psi | 89% | 2608 fps | 100% |
| SNPE Vectan SP 13ᴾ | <<locked>> | 100% | 44,353 psi | 64% | 2484 fps | 97% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 62,352 psi | 90% | 2566 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 59,915 psi | 86% | 2651 fps | 100% |
| Somchem S361 | <<locked>> | 86% | 59,074 psi | 85% | 2592 fps | 100% |
| Somchem S365 | <<locked>> | 84% | 59,799 psi | 86% | 2579 fps | 100% |
| Somchem S385 | <<locked>> | 88% | 60,466 psi | 87% | 2621 fps | 100% |
| Unknown powder | <<locked>> | 82% | 61,873 psi | 89% | 2621 fps | 100% |
| Vihtavuori N150 | <<locked>> | 84% | 60,582 psi | 87% | 2503 fps | 100% |
| Vihtavuori N160 | <<locked>> | 82% | 62,192 psi | 89% | 2589 fps | 100% |
| Vihtavuori N165 | <<locked>> | 94% | 62,410 psi | 90% | 2631 fps | 100% |
| Vihtavuori N170ᴾ | <<locked>> | 100% | 56,913 psi | 82% | 2625 fps | 98.7% |
| Vihtavuori N550 | <<locked>> | 82% | 62,743 psi | 90% | 2635 fps | 100% |
| Vihtavuori N555 | <<locked>> | 88% | 59,654 psi | 86% | 2612 fps | 100% |
| Vihtavuori N560 | <<locked>> | 90% | 60,263 psi | 87% | 2726 fps | 100% |
| Vihtavuori N565 | <<locked>> | 94% | 59,828 psi | 86% | 2703 fps | 100% |
| Vihtavuori N568 | <<locked>> | 98% | 61,656 psi | 89% | 2779 fps | 100% |
| Vihtavuori N570 | <<locked>> | 98% | 59,248 psi | 85% | 2792 fps | 99.7% |
| Winchester 6.5 StaBALL | <<locked>> | 82% | 59,132 psi | 85% | 2523 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 92% | 62,163 psi | 89% | 2726 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 88% | 62,062 psi | 89% | 2641 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% | 42,496 psi | 61% | 2356 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 56,202 psi | 81% | 2546 fps | 100% |
| Accurate 8700 | <<locked>> | 98% | 39,363 psi | 57% | 2415 fps | 95.9% |
| Accurate MAGPRO | <<locked>> | 80% | 41,872 psi | 60% | 2448 fps | 98.3% |
| ADI APS 450 | <<locked>> | 80% | 59,408 psi | 85% | 1972 fps | 100% |
| ADI AR 2209 | <<locked>> | 80% | 46,862 psi | 67% | 2477 fps | 100% |
| ADI AR 2213 | <<locked>> | 80% | 42,061 psi | 60% | 2438 fps | 99.5% |
| ADI AR 2217 | <<locked>> | 80% | 31,154 psi | 45% | 2215 fps | 97.2% |
| ADI AR 2218 | <<locked>> | 90% | 37,478 psi | 54% | 2441 fps | 95.7% |
| ADI AR 2225 | <<locked>> | 80% | 28,427 psi | 41% | 2192 fps | 98.9% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 47,282 psi | 68% | 2477 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 54,085 psi | 78% | 2552 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 46,804 psi | 67% | 2470 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 80% | 42,670 psi | 61% | 2438 fps | 99.9% |
| Alliant Reloder-23 | <<locked>> | 80% | 41,452 psi | 60% | 2369 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 35,766 psi | 51% | 2333 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 80% | 46,804 psi | 67% | 2526 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 86% | 35,230 psi | 51% | 2372 fps | 95.2% |
| Alliant Reloder-50 | <<locked>> | 92% | 37,304 psi | 54% | 2421 fps | 95.4% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 40,799 psi | 59% | 2365 fps | 97% |
| Bofors RP15 | <<locked>> | 80% | 39,755 psi | 57% | 2385 fps | 99.7% |
| Bofors RP30 | <<locked>> | 80% | 33,272 psi | 48% | 2283 fps | 98.1% |
| Bofors RP5 | <<locked>> | 80% | 42,670 psi | 61% | 2438 fps | 99.9% |
| Bofors RP7 | <<locked>> | 80% | 57,232 psi | 82% | 2546 fps | 100% |
| Hodgdon H1000 | <<locked>> | 80% | 32,010 psi | 46% | 2234 fps | 98.1% |
| Hodgdon H4350 | <<locked>> | 80% | 54,911 psi | 79% | 2549 fps | 100% |
| Hodgdon H4831 | <<locked>> | 80% | 39,392 psi | 57% | 2336 fps | 98.5% |
| Hodgdon H4831 SC | <<locked>> | 80% | 43,830 psi | 63% | 2418 fps | 99.3% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 50,720 psi | 73% | 2438 fps | 100% |
| Hodgdon Retumbo | 79.6 gr | 80% | 34,998 psi | 50% | 2385 fps | 99.7% |
| Hodgdon Superformance | <<locked>> | 80% | 58,552 psi | 84% | 2644 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,340 psi | 41% | 1427 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 52,518 psi | 75% | 2497 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 80% | 58,581 psi | 84% | 2562 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 48,211 psi | 69% | 2431 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 45,687 psi | 66% | 2418 fps | 99.6% |
| IMR 7828 SSC | <<locked>> | 80% | 43,526 psi | 63% | 2470 fps | 99.7% |
| IMR 7977 Enduron | <<locked>> | 88% | 47,166 psi | 68% | 2418 fps | 95.3% |
| IMR 8133 Enduron | <<locked>> | 82% | 27,760 psi | 40% | 2169 fps | 95.7% |
| Lovex D100 | <<locked>> | 96% | 53,156 psi | 76% | 2562 fps | 95.7% |
| Lovex S065 | <<locked>> | 80% | 55,970 psi | 80% | 2513 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 54,505 psi | 78% | 2520 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 36,593 psi | 53% | 2254 fps | 100% |
| Norma 204 | <<locked>> | 80% | 53,359 psi | 77% | 2552 fps | 100% |
| Norma 217 | <<locked>> | 80% | 26,005 psi | 37% | 2139 fps | 97.2% |
| Norma MRP | <<locked>> | 80% | 45,324 psi | 65% | 2500 fps | 100% |
| Norma URP | <<locked>> | 80% | 54,549 psi | 78% | 2533 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 46,064 psi | 66% | 2523 fps | 100% |
| Ramshot Hunter | <<locked>> | 80% | 53,403 psi | 77% | 2546 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 40,176 psi | 58% | 2392 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,051 psi | 42% | 1463 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 56,347 psi | 81% | 2572 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 55,071 psi | 79% | 2602 fps | 100% |
| ReloadSwiss RS 76 | 85.2 gr | 80% | 34,011 psi | 49% | 2362 fps | 99.9% |
| ReloadSwiss RS 80 | <<locked>> | 80% | 30,850 psi | 44% | 2264 fps | 95.7% |
| Rottweil R 904 | <<locked>> | 80% | 47,659 psi | 68% | 2451 fps | 99.9% |
| Rottweil R 905 | <<locked>> | 80% | 46,398 psi | 67% | 2461 fps | 100% |
| Rottweil R 907 | <<locked>> | 80% | 57,232 psi | 82% | 2546 fps | 100% |
| Shooters World 50 BMG | <<locked>> | 96% | 53,156 psi | 76% | 2562 fps | 95.7% |
| Shooters World Long Rifle | <<locked>> | 80% | 55,970 psi | 80% | 2513 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 54,505 psi | 78% | 2520 fps | 100% |
| SNPE Vectan SP 13 | <<locked>> | 96% | 38,624 psi | 55% | 2379 fps | 95.3% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 54,752 psi | 79% | 2474 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 46,064 psi | 66% | 2457 fps | 100% |
| Somchem S361 | <<locked>> | 80% | 48,443 psi | 70% | 2444 fps | 99.7% |
| Somchem S365 | <<locked>> | 80% | 52,272 psi | 75% | 2487 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 46,586 psi | 67% | 2434 fps | 100% |
| Unknown powder | <<locked>> | 80% | 58,175 psi | 84% | 2579 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 53,708 psi | 77% | 2421 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 58,262 psi | 84% | 2546 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 39,552 psi | 57% | 2313 fps | 99.8% |
| Vihtavuori N170 | <<locked>> | 90% | 41,278 psi | 59% | 2375 fps | 95.4% |
| Vihtavuori N550 | <<locked>> | 80% | 58,842 psi | 85% | 2589 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 45,963 psi | 66% | 2434 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 42,931 psi | 62% | 2464 fps | 99.3% |
| Vihtavuori N565 | <<locked>> | 80% | 37,144 psi | 53% | 2343 fps | 98.4% |
| Vihtavuori N568 | <<locked>> | 80% | 32,256 psi | 46% | 2280 fps | 95.6% |
| Vihtavuori N570 | 89.7 gr | 86% | 38,305 psi | 55% | 2444 fps | 95.9% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 55,274 psi | 79% | 2477 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 39,523 psi | 57% | 2431 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 46,847 psi | 67% | 2444 fps | 100% |
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 | 300gr | CutEdge MTH. Hodgdon Retumbo delivers the highest muzzle velocity at 2,805 fps; across all powders the maximum-charge window runs from 1,598 fps to 2,805 fps. Accurate 8700 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 300.0 gr projectile in 0.338" calls for a 1:9.5 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 N570 rank at the top here: for .338 Lapua Mag. Ackley Improved with the .338 | 300gr | CutEdge MTH 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.