Load Specifications
Load data in caliber 8.5 mm Messner Mag. with .338 | 250gr | Alaska Bullet Works Kodiak PP SPBC bullet and 78 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Vihtavuori N560, Norma MRP and Accurate MAGPRO.
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>> | 96% | 56,217 psi | 88% | 2730 fps | 100% |
| Accurate 4350 | <<locked>> | 86% | 54,259 psi | 85% | 2710 fps | 100% |
| Accurate MAGPRO | <<locked>> | 94% | 54,679 psi | 86% | 2825 fps | 98.4% |
| ADI AR 2208 | <<locked>> | 82% | 55,535 psi | 87% | 2667 fps | 100% |
| ADI AR 2209 | <<locked>> | 92% | 54,897 psi | 86% | 2766 fps | 99.7% |
| ADI AR 2213 | <<locked>> | 96% | 56,115 psi | 88% | 2825 fps | 99.2% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 46,963 psi | 74% | 2671 fps | 98.1% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 41,640 psi | 65% | 2635 fps | 99.5% |
| Alliant Reloder- TS 15.5 | <<locked>> | 82% | 56,927 psi | 89% | 2690 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 88% | 55,056 psi | 86% | 2762 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 84% | 56,043 psi | 88% | 2772 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 92% | 54,346 psi | 85% | 2756 fps | 99.6% |
| Alliant Reloder-22 | <<locked>> | 96% | 55,941 psi | 88% | 2822 fps | 99.8% |
| Alliant Reloder-23 | <<locked>> | 98% | 57,072 psi | 89% | 2785 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 52,634 psi | 82% | 2795 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 94% | 57,609 psi | 90% | 2881 fps | 100% |
| Baschieri & Pellagri 109 | <<locked>> | 96% | 54,679 psi | 86% | 2733 fps | 96.6% |
| Bofors RP15 | <<locked>> | 98% | 54,853 psi | 86% | 2805 fps | 99.7% |
| Bofors RP30ᴾ | <<locked>> | 100% | 48,689 psi | 76% | 2743 fps | 98.7% |
| Bofors RP5 | <<locked>> | 96% | 55,941 psi | 88% | 2822 fps | 99.8% |
| Bofors RP7 | <<locked>> | 86% | 56,797 psi | 89% | 2707 fps | 100% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 51,648 psi | 81% | 2753 fps | 99.3% |
| Hodgdon H414 | <<locked>> | 86% | 55,985 psi | 88% | 2762 fps | 100% |
| Hodgdon H4350 | <<locked>> | 84% | 55,143 psi | 86% | 2720 fps | 99.7% |
| Hodgdon H4831 | <<locked>> | 94% | 56,318 psi | 88% | 2766 fps | 98.8% |
| Hodgdon H4831 SC | <<locked>> | 94% | 55,056 psi | 86% | 2746 fps | 98.6% |
| Hodgdon Hybrid 100V | <<locked>> | 90% | 55,317 psi | 87% | 2684 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 51,445 psi | 81% | 2861 fps | 99.9% |
| Hodgdon Superformance | <<locked>> | 86% | 56,202 psi | 88% | 2802 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,072 psi | 58% | 1677 fps | 100% |
| IMR 4350 | <<locked>> | 88% | 54,766 psi | 86% | 2697 fps | 99.9% |
| IMR 4451 Enduron | <<locked>> | 84% | 54,926 psi | 86% | 2680 fps | 100% |
| IMR 4831 | <<locked>> | 88% | 54,476 psi | 85% | 2700 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 94% | 57,450 psi | 90% | 2749 fps | 99% |
| IMR 7828 SSC | <<locked>> | 96% | 54,027 psi | 85% | 2802 fps | 99.1% |
| Lovex S065 | <<locked>> | 86% | 55,419 psi | 87% | 2680 fps | 100% |
| Lovex S070 | <<locked>> | 88% | 56,971 psi | 89% | 2726 fps | 100% |
| Lovex S071ᴾ | <<locked>> | 100% | 53,592 psi | 84% | 2694 fps | 100% |
| Norma 204 | <<locked>> | 88% | 55,593 psi | 87% | 2753 fps | 99.6% |
| Norma 217ᴾ | <<locked>> | 100% | 37,275 psi | 58% | 2566 fps | 98% |
| Norma MRP | <<locked>> | 94% | 55,883 psi | 88% | 2844 fps | 100% |
| Norma URP | <<locked>> | 88% | 56,260 psi | 88% | 2743 fps | 100% |
| Ramshot Grand | <<locked>> | 96% | 54,505 psi | 85% | 2822 fps | 99.4% |
| Ramshot Hunter | <<locked>> | 88% | 55,027 psi | 86% | 2749 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 56,637 psi | 89% | 2815 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,898 psi | 59% | 1716 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 57,580 psi | 90% | 2717 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 82% | 55,709 psi | 87% | 2762 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 86% | 53,998 psi | 85% | 2733 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 88% | 56,115 psi | 88% | 2812 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 51,982 psi | 81% | 2861 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 46,702 psi | 73% | 2746 fps | 97.1% |
| Rottweil R 903 | <<locked>> | 82% | 54,636 psi | 86% | 2657 fps | 100% |
| Rottweil R 904 | <<locked>> | 92% | 56,289 psi | 88% | 2736 fps | 99.2% |
| Rottweil R 905 | <<locked>> | 94% | 57,551 psi | 90% | 2795 fps | 99.9% |
| Rottweil R 907 | <<locked>> | 86% | 56,797 psi | 89% | 2707 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 86% | 55,419 psi | 87% | 2680 fps | 100% |
| Shooters World SW4350 | <<locked>> | 88% | 56,971 psi | 89% | 2726 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 82% | 56,086 psi | 88% | 2713 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 82% | 54,708 psi | 86% | 2533 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 54,621 psi | 86% | 2635 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 57,101 psi | 89% | 2792 fps | 99.8% |
| Somchem S355 | <<locked>> | 82% | 54,375 psi | 85% | 2651 fps | 100% |
| Somchem S361 | <<locked>> | 90% | 54,201 psi | 85% | 2677 fps | 98.4% |
| Somchem S365 | <<locked>> | 90% | 56,492 psi | 89% | 2743 fps | 100% |
| Somchem S385 | <<locked>> | 92% | 54,375 psi | 85% | 2717 fps | 99.9% |
| Vihtavuori N150 | <<locked>> | 84% | 55,564 psi | 87% | 2625 fps | 100% |
| Vihtavuori N160 | <<locked>> | 86% | 54,621 psi | 86% | 2687 fps | 100% |
| Vihtavuori N165 | <<locked>> | 98% | 57,450 psi | 90% | 2749 fps | 99.9% |
| Vihtavuori N550 | <<locked>> | 88% | 57,348 psi | 90% | 2743 fps | 100% |
| Vihtavuori N555 | <<locked>> | 94% | 55,927 psi | 88% | 2766 fps | 100% |
| Vihtavuori N560 | <<locked>> | 94% | 55,782 psi | 87% | 2838 fps | 99% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 55,245 psi | 87% | 2818 fps | 99.1% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 48,095 psi | 75% | 2753 fps | 96.8% |
| Winchester 6.5 StaBALL | <<locked>> | 88% | 57,580 psi | 90% | 2694 fps | 100% |
| Winchester 760 | <<locked>> | 86% | 56,188 psi | 88% | 2766 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 98% | 54,114 psi | 85% | 2867 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 94% | 54,143 psi | 85% | 2713 fps | 99.6% |
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% | 32,924 psi | 52% | 2323 fps | 97.7% |
| Accurate 4350 | <<locked>> | 80% | 44,222 psi | 69% | 2556 fps | 100% |
| Accurate MAGPRO | 81.6 gr | 86% | 41,292 psi | 65% | 2589 fps | 95.3% |
| ADI AR 2208 | <<locked>> | 80% | 52,315 psi | 82% | 2621 fps | 100% |
| ADI AR 2209 | <<locked>> | 80% | 36,985 psi | 58% | 2441 fps | 96.3% |
| ADI AR 2213 | <<locked>> | 84% | 37,681 psi | 59% | 2484 fps | 95% |
| ADI AR 2217 | <<locked>> | 94% | 38,595 psi | 60% | 2503 fps | 95.6% |
| ADI AR 2225 | <<locked>> | 90% | 30,443 psi | 48% | 2356 fps | 95.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 53,417 psi | 84% | 2641 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 42,351 psi | 66% | 2562 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 80% | 48,834 psi | 77% | 2671 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 36,985 psi | 58% | 2438 fps | 96.4% |
| Alliant Reloder-22 | <<locked>> | 80% | 32,851 psi | 51% | 2382 fps | 95% |
| Alliant Reloder-23 | <<locked>> | 80% | 31,662 psi | 50% | 2352 fps | 99.8% |
| Alliant Reloder-25 | <<locked>> | 80% | 27,615 psi | 43% | 2264 fps | 96.1% |
| Alliant Reloder-26 | <<locked>> | 80% | 34,287 psi | 54% | 2480 fps | 99.3% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 48,370 psi | 76% | 2625 fps | 95% |
| Bofors RP15 | <<locked>> | 84% | 34,925 psi | 55% | 2431 fps | 95.7% |
| Bofors RP30 | <<locked>> | 92% | 37,115 psi | 58% | 2516 fps | 95.8% |
| Bofors RP5 | <<locked>> | 80% | 32,851 psi | 51% | 2382 fps | 95% |
| Bofors RP7 | <<locked>> | 80% | 47,224 psi | 74% | 2559 fps | 99.3% |
| Hodgdon H1000 | <<locked>> | 90% | 36,927 psi | 58% | 2467 fps | 95.7% |
| Hodgdon H414 | <<locked>> | 80% | 45,948 psi | 72% | 2605 fps | 99.5% |
| Hodgdon H4350 | <<locked>> | 80% | 48,588 psi | 76% | 2618 fps | 99.1% |
| Hodgdon H4831 | <<locked>> | 84% | 40,234 psi | 63% | 2490 fps | 95.3% |
| Hodgdon H4831 SC | <<locked>> | 84% | 39,508 psi | 62% | 2474 fps | 95.1% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 40,089 psi | 63% | 2454 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 86% | 32,706 psi | 51% | 2448 fps | 95.3% |
| Hodgdon Superformance | <<locked>> | 80% | 45,223 psi | 71% | 2628 fps | 99.3% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,789 psi | 44% | 1496 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 42,656 psi | 67% | 2497 fps | 98.7% |
| IMR 4451 Enduron | <<locked>> | 80% | 48,617 psi | 76% | 2582 fps | 99.7% |
| IMR 4831 | <<locked>> | 80% | 42,105 psi | 66% | 2507 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 82% | 39,494 psi | 62% | 2438 fps | 95.3% |
| IMR 7828 SSC | <<locked>> | 86% | 38,653 psi | 61% | 2520 fps | 95.6% |
| Lovex S065 | <<locked>> | 80% | 46,224 psi | 72% | 2536 fps | 99.9% |
| Lovex S070 | <<locked>> | 80% | 44,382 psi | 70% | 2526 fps | 99.4% |
| Lovex S071 | <<locked>> | 80% | 28,369 psi | 44% | 2208 fps | 95.9% |
| Norma 204 | <<locked>> | 80% | 42,467 psi | 67% | 2530 fps | 97.7% |
| Norma 217 | <<locked>> | 94% | 30,690 psi | 48% | 2398 fps | 95.2% |
| Norma MRP | 74.5 gr | 80% | 34,171 psi | 54% | 2444 fps | 97.1% |
| Norma URP | <<locked>> | 80% | 43,453 psi | 68% | 2543 fps | 100% |
| Ramshot Grand | <<locked>> | 86% | 38,159 psi | 60% | 2523 fps | 95.8% |
| Ramshot Hunter | <<locked>> | 80% | 42,206 psi | 66% | 2543 fps | 99.5% |
| Ramshot Magnum | <<locked>> | 84% | 31,662 psi | 50% | 2352 fps | 95.3% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,311 psi | 44% | 1532 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 54,114 psi | 85% | 2667 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 51,808 psi | 81% | 2710 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 44,005 psi | 69% | 2575 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 42,337 psi | 66% | 2595 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 86% | 31,720 psi | 50% | 2425 fps | 96.1% |
| ReloadSwiss RS 80 | <<locked>> | 96% | 40,466 psi | 63% | 2621 fps | 95.1% |
| Rottweil R 903 | <<locked>> | 80% | 51,213 psi | 80% | 2608 fps | 100% |
| Rottweil R 904 | <<locked>> | 80% | 38,406 psi | 60% | 2421 fps | 95.5% |
| Rottweil R 905 | <<locked>> | 80% | 36,303 psi | 57% | 2425 fps | 96.4% |
| Rottweil R 907 | <<locked>> | 80% | 47,224 psi | 74% | 2559 fps | 99.3% |
| Shooters World Long Rifle | <<locked>> | 80% | 46,224 psi | 72% | 2536 fps | 99.9% |
| Shooters World SW4350 | <<locked>> | 80% | 44,382 psi | 70% | 2526 fps | 99.4% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 52,431 psi | 82% | 2664 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 51,445 psi | 81% | 2490 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 45,179 psi | 71% | 2487 fps | 99.4% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 35,984 psi | 56% | 2418 fps | 96.2% |
| Somchem S355 | <<locked>> | 80% | 51,213 psi | 80% | 2605 fps | 100% |
| Somchem S361 | <<locked>> | 82% | 41,669 psi | 65% | 2467 fps | 95.7% |
| Somchem S365 | <<locked>> | 80% | 40,350 psi | 63% | 2503 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 36,869 psi | 58% | 2408 fps | 97.4% |
| Vihtavuori N150 | <<locked>> | 80% | 48,849 psi | 77% | 2533 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 44,918 psi | 70% | 2539 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 31,850 psi | 50% | 2290 fps | 95.2% |
| Vihtavuori N550 | <<locked>> | 80% | 44,324 psi | 69% | 2543 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 35,433 psi | 56% | 2421 fps | 99.7% |
| Vihtavuori N560 | 78.2 gr | 84% | 39,523 psi | 62% | 2549 fps | 95.4% |
| Vihtavuori N565 | <<locked>> | 90% | 39,378 psi | 62% | 2539 fps | 95.7% |
| Vihtavuori N568 | <<locked>> | 96% | 41,974 psi | 66% | 2635 fps | 95% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 43,787 psi | 69% | 2503 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 46,122 psi | 72% | 2608 fps | 99.5% |
| Winchester StaBALL HD | <<locked>> | 80% | 27,992 psi | 44% | 2365 fps | 99.9% |
| Winchester Supreme 780 | <<locked>> | 80% | 33,475 psi | 52% | 2333 fps | 95.1% |
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 78 powders for 8.5 mm Messner Mag. loaded with the .338 | 250gr | Alaska Bullet Works Kodiak PP SPBC. Alliant Reloder-26 delivers the highest muzzle velocity at 2,881 fps; across all powders the maximum-charge window runs from 1,677 fps to 2,881 fps. ADI AR 2217 gives the best case fill at 100 %, and 78 of the 78 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 250.0 gr projectile in 0.338" calls for a 1:16.0 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. Vihtavuori N560, Norma MRP, Accurate MAGPRO rank at the top here: for 8.5 mm Messner Mag. with the .338 | 250gr | Alaska Bullet Works Kodiak PP 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.