Load Specifications
Load data in caliber 8.5 mm Messner Mag. with .338 | 275gr | Alaska Bullet Works Kodiak SP SPBC bullet and 77 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Winchester StaBALL HD, Vihtavuori N560 and Norma MRP.
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: 25.6"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 94% | 55,390 psi | 87% | 2589 fps | 100% |
| Accurate 4350 | <<locked>> | 86% | 57,014 psi | 89% | 2612 fps | 100% |
| Accurate MAGPRO | <<locked>> | 92% | 53,882 psi | 84% | 2687 fps | 98.9% |
| ADI AR 2208 | <<locked>> | 82% | 57,740 psi | 90% | 2559 fps | 100% |
| ADI AR 2209 | <<locked>> | 92% | 57,682 psi | 90% | 2674 fps | 100% |
| ADI AR 2213 | <<locked>> | 94% | 55,187 psi | 86% | 2680 fps | 99.6% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 49,458 psi | 78% | 2595 fps | 99.2% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 44,092 psi | 69% | 2566 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 86% | 54,172 psi | 85% | 2612 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 82% | 55,187 psi | 86% | 2621 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 92% | 57,058 psi | 89% | 2664 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 94% | 55,245 psi | 87% | 2677 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 96% | 56,579 psi | 89% | 2641 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 55,753 psi | 87% | 2707 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 92% | 56,971 psi | 89% | 2733 fps | 100% |
| Baschieri & Pellagri 109 | <<locked>> | 96% | 56,855 psi | 89% | 2648 fps | 97.9% |
| Bofors RP15 | <<locked>> | 96% | 54,433 psi | 85% | 2667 fps | 99.9% |
| Bofors RP30ᴾ | <<locked>> | 100% | 51,576 psi | 81% | 2661 fps | 99.6% |
| Bofors RP5 | <<locked>> | 94% | 55,245 psi | 87% | 2677 fps | 100% |
| Bofors RP7 | <<locked>> | 84% | 55,666 psi | 87% | 2562 fps | 100% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 54,563 psi | 86% | 2671 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 84% | 54,998 psi | 86% | 2618 fps | 100% |
| Hodgdon H4350 | <<locked>> | 84% | 57,682 psi | 90% | 2625 fps | 100% |
| Hodgdon H4831 | <<locked>> | 92% | 55,245 psi | 87% | 2625 fps | 99.2% |
| Hodgdon H4831 SC | <<locked>> | 92% | 54,201 psi | 85% | 2608 fps | 99.1% |
| Hodgdon Hybrid 100V | <<locked>> | 88% | 54,433 psi | 85% | 2539 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 54,563 psi | 86% | 2779 fps | 100% |
| Hodgdon Superformance | <<locked>> | 84% | 55,143 psi | 86% | 2654 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,173 psi | 58% | 1588 fps | 100% |
| IMR 4350 | <<locked>> | 88% | 57,188 psi | 90% | 2598 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 84% | 57,116 psi | 90% | 2582 fps | 100% |
| IMR 4831 | <<locked>> | 88% | 57,145 psi | 90% | 2602 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 92% | 56,362 psi | 88% | 2608 fps | 99.4% |
| IMR 7828 SSC | <<locked>> | 96% | 56,811 psi | 89% | 2717 fps | 99.8% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 39,755 psi | 62% | 2484 fps | 97.6% |
| Lovex S065 | <<locked>> | 84% | 54,404 psi | 85% | 2533 fps | 100% |
| Lovex S070 | <<locked>> | 86% | 55,970 psi | 88% | 2582 fps | 100% |
| Lovex S071ᴾ | <<locked>> | 100% | 56,463 psi | 88% | 2602 fps | 100% |
| Norma 204 | <<locked>> | 86% | 54,462 psi | 85% | 2605 fps | 99.8% |
| Norma 217ᴾ | <<locked>> | 100% | 39,711 psi | 62% | 2503 fps | 99.3% |
| Norma MRP | <<locked>> | 92% | 55,129 psi | 86% | 2697 fps | 100% |
| Norma URP | <<locked>> | 86% | 55,405 psi | 87% | 2595 fps | 100% |
| Ramshot Grand | <<locked>> | 94% | 53,751 psi | 84% | 2684 fps | 99.7% |
| Ramshot Hunter | <<locked>> | 88% | 57,711 psi | 90% | 2654 fps | 100% |
| Ramshot Magnum | <<locked>> | 98% | 55,767 psi | 87% | 2674 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,087 psi | 60% | 1627 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 86% | 57,000 psi | 89% | 2635 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 86% | 55,216 psi | 87% | 2664 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 55,027 psi | 86% | 2776 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 49,908 psi | 78% | 2680 fps | 98.6% |
| Rottweil R 903 | <<locked>> | 82% | 57,217 psi | 90% | 2556 fps | 100% |
| Rottweil R 904 | <<locked>> | 90% | 55,274 psi | 87% | 2595 fps | 99.6% |
| Rottweil R 905 | <<locked>> | 92% | 56,637 psi | 89% | 2651 fps | 100% |
| Rottweil R 907 | <<locked>> | 84% | 55,666 psi | 87% | 2562 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 84% | 54,404 psi | 85% | 2533 fps | 100% |
| Shooters World SW4350 | <<locked>> | 86% | 55,970 psi | 88% | 2582 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 82% | 56,927 psi | 89% | 2428 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 57,043 psi | 89% | 2539 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 92% | 56,202 psi | 88% | 2648 fps | 100% |
| Somchem S355 | <<locked>> | 82% | 56,768 psi | 89% | 2549 fps | 100% |
| Somchem S361 | <<locked>> | 90% | 56,652 psi | 89% | 2592 fps | 99.3% |
| Somchem S365 | <<locked>> | 88% | 55,738 psi | 87% | 2595 fps | 100% |
| Somchem S385 | <<locked>> | 92% | 57,159 psi | 90% | 2625 fps | 100% |
| Vihtavuori N150 | <<locked>> | 82% | 54,491 psi | 85% | 2480 fps | 100% |
| Vihtavuori N160 | <<locked>> | 86% | 57,159 psi | 90% | 2585 fps | 100% |
| Vihtavuori N165 | <<locked>> | 96% | 56,637 psi | 89% | 2608 fps | 100% |
| Vihtavuori N170ᴾ | <<locked>> | 100% | 54,969 psi | 86% | 2621 fps | 95.9% |
| Vihtavuori N550 | <<locked>> | 86% | 56,173 psi | 88% | 2592 fps | 100% |
| Vihtavuori N555 | <<locked>> | 92% | 55,216 psi | 87% | 2618 fps | 100% |
| Vihtavuori N560 | <<locked>> | 92% | 54,998 psi | 86% | 2697 fps | 99.4% |
| Vihtavuori N565 | <<locked>> | 98% | 54,607 psi | 86% | 2680 fps | 99.5% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 51,242 psi | 80% | 2684 fps | 98.4% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 48,385 psi | 76% | 2671 fps | 96% |
| Winchester 6.5 StaBALL | <<locked>> | 86% | 56,492 psi | 89% | 2549 fps | 100% |
| Winchester 760 | <<locked>> | 84% | 54,998 psi | 86% | 2618 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 96% | 54,201 psi | 85% | 2723 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 94% | 56,956 psi | 89% | 2625 fps | 100% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 25.6"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 80% | 34,882 psi | 55% | 2254 fps | 98.9% |
| Accurate 4350 | <<locked>> | 80% | 46,659 psi | 73% | 2467 fps | 100% |
| Accurate MAGPRO | <<locked>> | 82% | 38,043 psi | 60% | 2408 fps | 95.3% |
| ADI AR 2208 | <<locked>> | 80% | 54,520 psi | 85% | 2520 fps | 100% |
| ADI AR 2209 | <<locked>> | 80% | 38,841 psi | 61% | 2365 fps | 97.8% |
| ADI AR 2213 | <<locked>> | 80% | 34,606 psi | 54% | 2303 fps | 95.1% |
| ADI AR 2217 | <<locked>> | 90% | 35,650 psi | 56% | 2329 fps | 95.8% |
| ADI AR 2225 | <<locked>> | 86% | 28,282 psi | 44% | 2198 fps | 95.8% |
| Alliant Reloder-16 | <<locked>> | 80% | 44,730 psi | 70% | 2474 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 80% | 51,547 psi | 81% | 2575 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 38,899 psi | 61% | 2362 fps | 97.9% |
| Alliant Reloder-22 | <<locked>> | 80% | 34,635 psi | 54% | 2316 fps | 96.8% |
| Alliant Reloder-23 | <<locked>> | 80% | 33,518 psi | 53% | 2280 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 29,109 psi | 46% | 2208 fps | 98% |
| Alliant Reloder-26 | <<locked>> | 80% | 36,535 psi | 57% | 2411 fps | 99.9% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 44,570 psi | 70% | 2444 fps | 95% |
| Bofors RP15 | <<locked>> | 80% | 32,329 psi | 51% | 2260 fps | 95.8% |
| Bofors RP30 | <<locked>> | 86% | 32,387 psi | 51% | 2297 fps | 95.1% |
| Bofors RP5 | <<locked>> | 80% | 34,635 psi | 54% | 2316 fps | 96.8% |
| Bofors RP7 | <<locked>> | 80% | 49,182 psi | 77% | 2467 fps | 99.8% |
| Hodgdon H1000 | <<locked>> | 86% | 34,069 psi | 53% | 2297 fps | 95.8% |
| Hodgdon H414 | <<locked>> | 80% | 48,182 psi | 76% | 2516 fps | 100% |
| Hodgdon H4350 | <<locked>> | 80% | 50,633 psi | 79% | 2523 fps | 99.7% |
| Hodgdon H4831 | <<locked>> | 80% | 36,941 psi | 58% | 2310 fps | 95.3% |
| Hodgdon H4831 SC | <<locked>> | 80% | 36,260 psi | 57% | 2297 fps | 95.1% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 42,148 psi | 66% | 2365 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 82% | 30,327 psi | 48% | 2277 fps | 95.4% |
| Hodgdon Superformance | <<locked>> | 80% | 47,601 psi | 75% | 2543 fps | 99.9% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,934 psi | 44% | 1417 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 44,614 psi | 70% | 2411 fps | 99.5% |
| IMR 4451 Enduron | <<locked>> | 80% | 50,575 psi | 79% | 2490 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 44,280 psi | 69% | 2418 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 38,754 psi | 61% | 2313 fps | 96.1% |
| IMR 7828 SSC | <<locked>> | 82% | 35,636 psi | 56% | 2339 fps | 95.6% |
| IMR 8133 Enduron | <<locked>> | 96% | 34,969 psi | 55% | 2379 fps | 95.9% |
| Lovex S065 | <<locked>> | 80% | 48,153 psi | 75% | 2444 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 46,383 psi | 73% | 2438 fps | 99.9% |
| Lovex S071 | <<locked>> | 80% | 30,095 psi | 47% | 2146 fps | 97.6% |
| Norma 204 | <<locked>> | 80% | 44,715 psi | 70% | 2454 fps | 98.9% |
| Norma 217 | <<locked>> | 90% | 28,790 psi | 45% | 2244 fps | 95.6% |
| Norma MRP | 72.4 gr | 80% | 36,230 psi | 57% | 2379 fps | 98.6% |
| Norma URP | <<locked>> | 80% | 45,629 psi | 72% | 2454 fps | 100% |
| Ramshot Grand | <<locked>> | 82% | 35,143 psi | 55% | 2346 fps | 95.9% |
| Ramshot Hunter | <<locked>> | 80% | 44,512 psi | 70% | 2461 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 29,095 psi | 46% | 2185 fps | 95.3% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,500 psi | 45% | 1453 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 46,456 psi | 73% | 2490 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 44,585 psi | 70% | 2507 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 82% | 29,196 psi | 46% | 2254 fps | 96.2% |
| ReloadSwiss RS 80 | <<locked>> | 92% | 37,289 psi | 58% | 2441 fps | 95.2% |
| Rottweil R 903 | <<locked>> | 80% | 53,563 psi | 84% | 2510 fps | 100% |
| Rottweil R 904 | <<locked>> | 80% | 40,219 psi | 63% | 2346 fps | 97.1% |
| Rottweil R 905 | <<locked>> | 80% | 38,305 psi | 60% | 2352 fps | 97.9% |
| Rottweil R 907 | <<locked>> | 80% | 49,182 psi | 77% | 2467 fps | 99.8% |
| Shooters World Long Rifle | <<locked>> | 80% | 48,153 psi | 75% | 2444 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 46,383 psi | 73% | 2438 fps | 99.9% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 53,461 psi | 84% | 2388 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 47,007 psi | 74% | 2398 fps | 99.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 37,971 psi | 60% | 2346 fps | 97.8% |
| Somchem S355 | <<locked>> | 80% | 53,388 psi | 84% | 2507 fps | 100% |
| Somchem S361 | <<locked>> | 80% | 40,799 psi | 64% | 2336 fps | 96.5% |
| Somchem S365 | <<locked>> | 80% | 42,728 psi | 67% | 2415 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 38,725 psi | 61% | 2333 fps | 98.6% |
| Vihtavuori N150 | <<locked>> | 80% | 50,981 psi | 80% | 2434 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 47,123 psi | 74% | 2448 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 33,620 psi | 53% | 2224 fps | 96.9% |
| Vihtavuori N170 | <<locked>> | 98% | 51,416 psi | 81% | 2566 fps | 95% |
| Vihtavuori N550 | <<locked>> | 80% | 46,427 psi | 73% | 2454 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 37,550 psi | 59% | 2346 fps | 100% |
| Vihtavuori N560 | 72.4 gr | 80% | 36,463 psi | 57% | 2369 fps | 95.4% |
| Vihtavuori N565 | <<locked>> | 86% | 36,535 psi | 57% | 2362 fps | 95.8% |
| Vihtavuori N568 | <<locked>> | 92% | 38,827 psi | 61% | 2457 fps | 95.1% |
| Vihtavuori N570 | <<locked>> | 98% | 45,194 psi | 71% | 2615 fps | 95% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 46,079 psi | 72% | 2411 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 48,370 psi | 76% | 2520 fps | 100% |
| Winchester StaBALL HD | 71.7 gr | 80% | 29,776 psi | 47% | 2313 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 35,404 psi | 55% | 2267 fps | 96.9% |
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 77 powders for 8.5 mm Messner Mag. loaded with the .338 | 275gr | Alaska Bullet Works Kodiak SP SPBC. Hodgdon Retumbo delivers the highest muzzle velocity at 2,779 fps; across all powders the maximum-charge window runs from 1,588 fps to 2,779 fps. ADI AR 2217 gives the best case fill at 100 %, and 77 of the 77 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 58–90 %, leaving at least 10 % headroom. The 275.0 gr projectile in 0.338" calls for a 1:15.0 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2225, Alliant Reloder-25 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. Winchester StaBALL HD, Vihtavuori N560, Norma MRP rank at the top here: for 8.5 mm Messner Mag. with the .338 | 275gr | Alaska Bullet Works Kodiak SP SPBC 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.