Load Specifications
Load data in caliber .338 Lapua Mag. Ackley Improved with .338 | 352gr | MAKER SUB-REX bullet and 64 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Vihtavuori N570, Alliant Reloder-33 and ADI AR 2218.
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 3100 | <<locked>> | 88% | 62,178 psi | 89% | 2395 fps | 100% |
| Accurate 8700ᴾ | <<locked>> | 100% | 48,747 psi | 70% | 2385 fps | 99.4% |
| Accurate MAGPRO | <<locked>> | 88% | 62,352 psi | 90% | 2533 fps | 100% |
| ADI APS 450 | <<locked>> | 82% | 61,641 psi | 89% | 1834 fps | 100% |
| ADI AR 2209 | <<locked>> | 84% | 59,422 psi | 85% | 2431 fps | 100% |
| ADI AR 2213 | <<locked>> | 88% | 62,033 psi | 89% | 2503 fps | 100% |
| ADI AR 2217 | <<locked>> | 96% | 61,017 psi | 88% | 2490 fps | 100% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 61,293 psi | 88% | 2641 fps | 100% |
| ADI AR 2225 | <<locked>> | 98% | 60,162 psi | 86% | 2510 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 86% | 62,613 psi | 90% | 2464 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 88% | 62,366 psi | 90% | 2493 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 88% | 60,568 psi | 87% | 2395 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 92% | 61,119 psi | 88% | 2470 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 84% | 61,786 psi | 89% | 2487 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 96% | 58,972 psi | 85% | 2562 fps | 100% |
| Alliant Reloder-50ᴾ | <<locked>> | 100% | 58,871 psi | 85% | 2566 fps | 100% |
| Baschieri & Pellagri 109 | <<locked>> | 90% | 61,670 psi | 89% | 2480 fps | 100% |
| Bofors RP15 | <<locked>> | 90% | 61,685 psi | 89% | 2487 fps | 100% |
| Bofors RP30 | <<locked>> | 94% | 60,843 psi | 87% | 2507 fps | 100% |
| Bofors RP5 | <<locked>> | 88% | 62,366 psi | 90% | 2493 fps | 100% |
| Hodgdon 50BMGᴾ | <<locked>> | 100% | 61,554 psi | 88% | 2566 fps | 96.5% |
| Hodgdon H1000 | <<locked>> | 96% | 62,801 psi | 90% | 2503 fps | 100% |
| Hodgdon H4831 | <<locked>> | 90% | 60,539 psi | 87% | 2441 fps | 100% |
| Hodgdon H4831 SC | <<locked>> | 86% | 59,509 psi | 85% | 2431 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 82% | 59,828 psi | 86% | 2326 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 92% | 61,090 psi | 88% | 2566 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 38,130 psi | 55% | 1470 fps | 100% |
| Hodgdon US 869ᴾ | <<locked>> | 100% | 53,650 psi | 77% | 2441 fps | 97.2% |
| IMR 4350 | <<locked>> | 82% | 61,221 psi | 88% | 2388 fps | 100% |
| IMR 4831 | <<locked>> | 84% | 60,379 psi | 87% | 2362 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 86% | 60,553 psi | 87% | 2418 fps | 100% |
| IMR 7828 SSC | <<locked>> | 86% | 60,466 psi | 87% | 2490 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 94% | 62,671 psi | 90% | 2441 fps | 99.3% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 58,871 psi | 85% | 2510 fps | 100% |
| Lovex D100 | <<locked>> | 96% | 59,582 psi | 86% | 2454 fps | 98.4% |
| Lovex S071 | <<locked>> | 92% | 60,336 psi | 87% | 2375 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 60,640 psi | 87% | 2520 fps | 100% |
| Norma MRP | <<locked>> | 86% | 62,903 psi | 90% | 2507 fps | 100% |
| Ramshot Grand | <<locked>> | 84% | 61,046 psi | 88% | 2497 fps | 100% |
| Ramshot LRTᴾ | <<locked>> | 100% | 60,597 psi | 87% | 2582 fps | 98.6% |
| Ramshot Magnum | <<locked>> | 88% | 62,236 psi | 89% | 2467 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 39,160 psi | 56% | 1503 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 92% | 61,917 psi | 89% | 2559 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 94% | 60,582 psi | 87% | 2552 fps | 100% |
| Rottweil R 904 | <<locked>> | 84% | 59,611 psi | 86% | 2402 fps | 100% |
| Rottweil R 905 | <<locked>> | 86% | 62,714 psi | 90% | 2457 fps | 100% |
| Shooters World 50 BMG | <<locked>> | 96% | 59,582 psi | 86% | 2454 fps | 98.4% |
| SNPE Vectan SP 13ᴾ | <<locked>> | 100% | 50,966 psi | 73% | 2392 fps | 99.4% |
| SNPE Vectan Tubal 8000 | <<locked>> | 86% | 62,352 psi | 90% | 2457 fps | 100% |
| Somchem S361 | <<locked>> | 84% | 60,800 psi | 87% | 2402 fps | 100% |
| Somchem S365 | <<locked>> | 82% | 62,308 psi | 90% | 2379 fps | 100% |
| Somchem S385 | <<locked>> | 86% | 62,772 psi | 90% | 2425 fps | 100% |
| Vihtavuori 20N29ᴾ | <<locked>> | 100% | 48,791 psi | 70% | 2388 fps | 98.1% |
| Vihtavuori 24N41ᴾ | <<locked>> | 100% | 61,438 psi | 88% | 2543 fps | 98.4% |
| Vihtavuori N150 | <<locked>> | 82% | 62,192 psi | 89% | 2303 fps | 100% |
| Vihtavuori N165 | <<locked>> | 90% | 60,916 psi | 88% | 2398 fps | 100% |
| Vihtavuori N170 | <<locked>> | 98% | 59,654 psi | 86% | 2457 fps | 99.8% |
| Vihtavuori N555 | <<locked>> | 86% | 62,453 psi | 90% | 2415 fps | 100% |
| Vihtavuori N560 | <<locked>> | 88% | 62,917 psi | 90% | 2533 fps | 100% |
| Vihtavuori N565 | <<locked>> | 90% | 59,045 psi | 85% | 2474 fps | 100% |
| Vihtavuori N568 | <<locked>> | 94% | 60,988 psi | 88% | 2549 fps | 100% |
| Vihtavuori N570 | <<locked>> | 94% | 58,943 psi | 85% | 2569 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 88% | 61,859 psi | 89% | 2487 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 84% | 60,002 psi | 86% | 2405 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% | 47,979 psi | 69% | 2231 fps | 100% |
| Accurate 8700 | <<locked>> | 88% | 32,155 psi | 46% | 2090 fps | 95.1% |
| Accurate MAGPRO | <<locked>> | 80% | 47,485 psi | 68% | 2339 fps | 99.9% |
| ADI APS 450 | <<locked>> | 80% | 59,596 psi | 86% | 1811 fps | 100% |
| ADI AR 2209 | <<locked>> | 80% | 52,127 psi | 75% | 2343 fps | 100% |
| ADI AR 2213 | <<locked>> | 80% | 47,500 psi | 68% | 2323 fps | 100% |
| ADI AR 2217 | <<locked>> | 80% | 35,534 psi | 51% | 2133 fps | 99.6% |
| ADI AR 2218 | 82.9 gr | 82% | 32,372 psi | 47% | 2149 fps | 95.8% |
| ADI AR 2225 | <<locked>> | 80% | 32,750 psi | 47% | 2119 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 51,866 psi | 75% | 2336 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 80% | 48,240 psi | 69% | 2320 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 80% | 47,065 psi | 68% | 2238 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 41,147 psi | 59% | 2221 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 80% | 53,563 psi | 77% | 2395 fps | 100% |
| Alliant Reloder-33 | 82.4 gr | 80% | 33,127 psi | 48% | 2146 fps | 96.3% |
| Alliant Reloder-50 | <<locked>> | 84% | 33,040 psi | 47% | 2149 fps | 95.8% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 44,991 psi | 65% | 2254 fps | 99.2% |
| Bofors RP15 | <<locked>> | 80% | 44,933 psi | 65% | 2270 fps | 100% |
| Bofors RP30 | <<locked>> | 80% | 38,406 psi | 55% | 2195 fps | 99.9% |
| Bofors RP5 | <<locked>> | 80% | 48,240 psi | 69% | 2320 fps | 100% |
| Hodgdon 50BMG | <<locked>> | 98% | 57,464 psi | 83% | 2513 fps | 95.7% |
| Hodgdon H1000 | <<locked>> | 80% | 36,477 psi | 52% | 2149 fps | 99.9% |
| Hodgdon H4831 | <<locked>> | 80% | 44,150 psi | 63% | 2224 fps | 99.9% |
| Hodgdon H4831 SC | <<locked>> | 80% | 48,965 psi | 70% | 2297 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 56,246 psi | 81% | 2287 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 80% | 40,263 psi | 58% | 2290 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,689 psi | 41% | 1309 fps | 100% |
| Hodgdon US 869 | <<locked>> | 96% | 46,847 psi | 67% | 2343 fps | 95.7% |
| IMR 4350 | <<locked>> | 80% | 57,537 psi | 83% | 2349 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 53,548 psi | 77% | 2287 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 50,285 psi | 72% | 2287 fps | 100% |
| IMR 7828 SSC | <<locked>> | 80% | 49,269 psi | 71% | 2352 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 80% | 40,408 psi | 58% | 2123 fps | 95.2% |
| IMR 8133 Enduron | <<locked>> | 80% | 30,487 psi | 44% | 2060 fps | 98.6% |
| Lovex D100 | <<locked>> | 88% | 45,266 psi | 65% | 2257 fps | 95.6% |
| Lovex S071 | <<locked>> | 80% | 41,640 psi | 60% | 2142 fps | 100% |
| Norma 217 | <<locked>> | 80% | 30,893 psi | 44% | 2083 fps | 99.8% |
| Norma MRP | <<locked>> | 80% | 51,285 psi | 74% | 2369 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 52,576 psi | 76% | 2402 fps | 100% |
| Ramshot LRT | <<locked>> | 92% | 45,977 psi | 66% | 2369 fps | 95.7% |
| Ramshot Magnum | <<locked>> | 80% | 46,209 psi | 66% | 2283 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,530 psi | 42% | 1342 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 39,523 psi | 57% | 2274 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 80% | 36,390 psi | 52% | 2201 fps | 99.1% |
| Rottweil R 904 | <<locked>> | 80% | 52,678 psi | 76% | 2316 fps | 100% |
| Rottweil R 905 | <<locked>> | 80% | 51,866 psi | 75% | 2333 fps | 100% |
| Shooters World 50 BMG | <<locked>> | 88% | 45,266 psi | 65% | 2257 fps | 95.6% |
| SNPE Vectan SP 13 | <<locked>> | 88% | 34,084 psi | 49% | 2106 fps | 95.6% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 51,517 psi | 74% | 2329 fps | 100% |
| Somchem S361 | <<locked>> | 80% | 53,505 psi | 77% | 2313 fps | 100% |
| Somchem S365 | <<locked>> | 80% | 58,407 psi | 84% | 2339 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 52,069 psi | 75% | 2303 fps | 100% |
| Vihtavuori 20N29 | <<locked>> | 94% | 39,363 psi | 57% | 2234 fps | 95.7% |
| Vihtavuori 24N41 | <<locked>> | 92% | 46,514 psi | 67% | 2336 fps | 95.6% |
| Vihtavuori N150 | <<locked>> | 80% | 58,581 psi | 84% | 2264 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 44,411 psi | 64% | 2195 fps | 100% |
| Vihtavuori N170 | <<locked>> | 82% | 36,260 psi | 52% | 2100 fps | 95.7% |
| Vihtavuori N555 | <<locked>> | 80% | 51,779 psi | 74% | 2297 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 48,472 psi | 70% | 2349 fps | 100% |
| Vihtavuori N565 | <<locked>> | 80% | 42,598 psi | 61% | 2251 fps | 99.9% |
| Vihtavuori N568 | <<locked>> | 80% | 37,521 psi | 54% | 2208 fps | 98.9% |
| Vihtavuori N570 | 80.1 gr | 80% | 35,969 psi | 52% | 2205 fps | 97% |
| Winchester StaBALL HD | <<locked>> | 80% | 46,485 psi | 67% | 2316 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 52,315 psi | 75% | 2316 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 64 powders for .338 Lapua Mag. Ackley Improved loaded with the .338 | 352gr | MAKER SUB-REX. ADI AR 2218 delivers the highest muzzle velocity at 2,641 fps; across all powders the maximum-charge window runs from 1,470 fps to 2,641 fps. Accurate 8700 gives the best case fill at 100 %, and 64 of the 64 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (480 MPa), the top charges use 55–90 %, leaving at least 10 % headroom. The 352.0 gr projectile in 0.338" calls for a 1:9.0 twist; slower twists will usually not stabilise this weight. Accurate 8700, ADI AR 2218, Alliant Reloder-50 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. Vihtavuori N570, Alliant Reloder-33, ADI AR 2218 rank at the top here: for .338 Lapua Mag. Ackley Improved with the .338 | 352gr | MAKER SUB-REX 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.