Load Specifications
Load data in caliber 8.5 mm Messner Mag. with .338 | 225gr | Hornady InterLock bullet and 92 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Accurate High Country, Norma MRP and Vihtavuori N560.
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.
A valid access license is required to use the Personalized Load Calculator.
You can find more information in our FAQ: How can I use the Personalized Load Calculator?
Max Load - Barrel Length: 25.6"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2495 | <<locked>> | 82% | 57,638 psi | 90% | 2753 fps | 100% |
| Accurate 2700 | <<locked>> | 82% | 55,492 psi | 87% | 2795 fps | 99.5% |
| Accurate 3100 | <<locked>> | 98% | 54,012 psi | 85% | 2844 fps | 100% |
| Accurate 4064 | <<locked>> | 82% | 54,636 psi | 86% | 2766 fps | 100% |
| Accurate 4350 | <<locked>> | 90% | 56,115 psi | 88% | 2890 fps | 100% |
| Accurate High Country | <<locked>> | 96% | 55,608 psi | 87% | 2999 fps | 98.7% |
| Accurate MAGPRO | <<locked>> | 98% | 56,550 psi | 89% | 2999 fps | 97.8% |
| ADI AR 2208 | <<locked>> | 84% | 54,926 psi | 86% | 2805 fps | 100% |
| ADI AR 2209 | <<locked>> | 96% | 57,101 psi | 89% | 2943 fps | 99.3% |
| ADI AR 2213 | <<locked>> | 98% | 54,810 psi | 86% | 2943 fps | 98.3% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 37,362 psi | 59% | 2657 fps | 97.3% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 55,825 psi | 87% | 2828 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 55,883 psi | 88% | 2851 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 92% | 57,072 psi | 89% | 2946 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 86% | 54,694 psi | 86% | 2913 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 96% | 56,478 psi | 89% | 2930 fps | 99.3% |
| Alliant Reloder-22 | <<locked>> | 98% | 54,070 psi | 85% | 2936 fps | 99.2% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 54,853 psi | 86% | 2910 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 47,239 psi | 74% | 2854 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 96% | 54,984 psi | 86% | 3002 fps | 100% |
| Baschieri & Pellagri 109ᴾ | <<locked>> | 100% | 57,421 psi | 90% | 2907 fps | 95.9% |
| Bofors RP15ᴾ | <<locked>> | 100% | 53,040 psi | 83% | 2920 fps | 99% |
| Bofors RP3 | <<locked>> | 84% | 56,710 psi | 89% | 2844 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 43,033 psi | 67% | 2776 fps | 96.5% |
| Bofors RP5 | <<locked>> | 98% | 54,070 psi | 85% | 2936 fps | 99.2% |
| Bofors RP7 | <<locked>> | 88% | 55,956 psi | 88% | 2838 fps | 99.6% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 46,804 psi | 73% | 2799 fps | 97.5% |
| Hodgdon H380 | <<locked>> | 84% | 57,000 psi | 89% | 2867 fps | 100% |
| Hodgdon H414 | <<locked>> | 88% | 54,491 psi | 85% | 2890 fps | 99.8% |
| Hodgdon H4350 | <<locked>> | 88% | 57,711 psi | 90% | 2904 fps | 99.5% |
| Hodgdon H4831 | <<locked>> | 96% | 54,839 psi | 86% | 2884 fps | 97.7% |
| Hodgdon H4831 SC | <<locked>> | 98% | 57,566 psi | 90% | 2923 fps | 98.1% |
| Hodgdon Hybrid 100V | <<locked>> | 94% | 57,305 psi | 90% | 2864 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 46,282 psi | 73% | 2900 fps | 98.7% |
| Hodgdon Superformance | <<locked>> | 88% | 54,795 psi | 86% | 2927 fps | 99.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,506 psi | 57% | 1762 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 54,244 psi | 85% | 2785 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 56,840 psi | 89% | 2828 fps | 99.9% |
| IMR 4350 | <<locked>> | 92% | 57,174 psi | 90% | 2874 fps | 99.7% |
| IMR 4451 Enduron | <<locked>> | 88% | 57,638 psi | 90% | 2867 fps | 99.9% |
| IMR 4831 | <<locked>> | 92% | 56,420 psi | 88% | 2877 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 57,392 psi | 90% | 2874 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 56,231 psi | 88% | 2871 fps | 98% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 55,956 psi | 88% | 2976 fps | 98.6% |
| Lovex S062 | <<locked>> | 82% | 54,491 psi | 85% | 2779 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 57,711 psi | 90% | 2858 fps | 100% |
| Lovex S070 | <<locked>> | 90% | 55,709 psi | 87% | 2854 fps | 99.9% |
| Lovex S071ᴾ | <<locked>> | 100% | 47,935 psi | 75% | 2753 fps | 99.7% |
| Norma 203B | <<locked>> | 82% | 55,187 psi | 86% | 2835 fps | 100% |
| Norma 204 | <<locked>> | 90% | 54,418 psi | 85% | 2877 fps | 98.9% |
| Norma MRP | <<locked>> | 98% | 57,725 psi | 90% | 3022 fps | 100% |
| Norma URP | <<locked>> | 90% | 54,781 psi | 86% | 2874 fps | 100% |
| Ramshot Big Game | <<locked>> | 82% | 56,275 psi | 88% | 2864 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 56,739 psi | 89% | 2995 fps | 98.9% |
| Ramshot Hunter | <<locked>> | 92% | 57,290 psi | 90% | 2933 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 50,676 psi | 79% | 2867 fps | 99.3% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,217 psi | 58% | 1804 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 56,840 psi | 89% | 2851 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 54,128 psi | 85% | 2900 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 56,144 psi | 88% | 2913 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 54,534 psi | 85% | 2943 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 46,325 psi | 73% | 2894 fps | 99.5% |
| Rottweil R 902 | <<locked>> | 82% | 56,405 psi | 88% | 2789 fps | 100% |
| Rottweil R 903 | <<locked>> | 86% | 56,797 psi | 89% | 2838 fps | 100% |
| Rottweil R 904 | <<locked>> | 94% | 55,085 psi | 86% | 2858 fps | 98.3% |
| Rottweil R 905 | <<locked>> | 96% | 55,941 psi | 88% | 2920 fps | 99.3% |
| Rottweil R 907 | <<locked>> | 88% | 55,956 psi | 88% | 2838 fps | 99.6% |
| Shooters World Long Rifle | <<locked>> | 90% | 57,711 psi | 90% | 2858 fps | 100% |
| Shooters World Precision | <<locked>> | 82% | 54,491 psi | 85% | 2779 fps | 100% |
| Shooters World SW4350 | <<locked>> | 90% | 55,709 psi | 87% | 2854 fps | 99.9% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 54,853 psi | 86% | 2851 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 57,479 psi | 90% | 2717 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 57,479 psi | 90% | 2818 fps | 99.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 96% | 55,463 psi | 87% | 2917 fps | 99.3% |
| Somchem S355 | <<locked>> | 86% | 56,753 psi | 89% | 2838 fps | 100% |
| Somchem S361 | <<locked>> | 94% | 56,811 psi | 89% | 2854 fps | 97.9% |
| Somchem S365 | <<locked>> | 92% | 54,389 psi | 85% | 2874 fps | 100% |
| Somchem S385 | <<locked>> | 96% | 56,405 psi | 88% | 2890 fps | 99.7% |
| Vihtavuori N135 | <<locked>> | 82% | 56,971 psi | 89% | 2743 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 57,087 psi | 89% | 2759 fps | 100% |
| Vihtavuori N150 | <<locked>> | 86% | 54,447 psi | 85% | 2759 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 56,898 psi | 89% | 2867 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 55,680 psi | 87% | 2867 fps | 99.5% |
| Vihtavuori N540 | <<locked>> | 82% | 55,129 psi | 86% | 2756 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 55,956 psi | 88% | 2874 fps | 100% |
| Vihtavuori N555 | <<locked>> | 98% | 57,188 psi | 90% | 2936 fps | 100% |
| Vihtavuori N560 | <<locked>> | 96% | 53,896 psi | 84% | 2953 fps | 97.9% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 49,269 psi | 77% | 2861 fps | 97.2% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 56,565 psi | 89% | 2828 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 54,679 psi | 86% | 2890 fps | 99.8% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 50,865 psi | 80% | 2986 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 98% | 56,695 psi | 89% | 2890 fps | 99.3% |
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 2495 | <<locked>> | 80% | 53,940 psi | 85% | 2707 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 51,909 psi | 81% | 2740 fps | 99.1% |
| Accurate 3100 | <<locked>> | 82% | 30,951 psi | 49% | 2402 fps | 95.8% |
| Accurate 4064 | <<locked>> | 80% | 51,227 psi | 80% | 2717 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 39,523 psi | 62% | 2608 fps | 99.5% |
| Accurate High Country | 83.2 gr | 88% | 41,771 psi | 65% | 2746 fps | 95.6% |
| Accurate MAGPRO | <<locked>> | 92% | 45,498 psi | 71% | 2808 fps | 95.2% |
| ADI AR 2208 | <<locked>> | 80% | 48,501 psi | 76% | 2707 fps | 100% |
| ADI AR 2209 | <<locked>> | 84% | 38,305 psi | 60% | 2598 fps | 95.4% |
| ADI AR 2213 | <<locked>> | 90% | 41,785 psi | 65% | 2700 fps | 95.1% |
| ADI AR 2225 | <<locked>> | 96% | 32,880 psi | 52% | 2536 fps | 95.1% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 49,110 psi | 77% | 2726 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 52,446 psi | 82% | 2799 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 38,435 psi | 60% | 2625 fps | 99.6% |
| Alliant Reloder-17 | <<locked>> | 80% | 44,048 psi | 69% | 2743 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 84% | 38,101 psi | 60% | 2592 fps | 95.5% |
| Alliant Reloder-22 | <<locked>> | 88% | 38,363 psi | 60% | 2641 fps | 95.8% |
| Alliant Reloder-23 | <<locked>> | 80% | 28,036 psi | 44% | 2379 fps | 98.1% |
| Alliant Reloder-25 | <<locked>> | 86% | 29,892 psi | 47% | 2448 fps | 95.8% |
| Alliant Reloder-26 | <<locked>> | 80% | 30,168 psi | 47% | 2497 fps | 96.9% |
| Baschieri & Pellagri 109 | <<locked>> | 98% | 53,998 psi | 85% | 2848 fps | 95% |
| Bofors RP15 | <<locked>> | 90% | 38,014 psi | 60% | 2631 fps | 95.4% |
| Bofors RP3 | <<locked>> | 80% | 49,545 psi | 78% | 2740 fps | 100% |
| Bofors RP30 | <<locked>> | 98% | 40,234 psi | 63% | 2717 fps | 95.6% |
| Bofors RP5 | <<locked>> | 88% | 38,363 psi | 60% | 2641 fps | 95.8% |
| Bofors RP7 | <<locked>> | 80% | 43,410 psi | 68% | 2625 fps | 97.9% |
| Hodgdon H1000 | <<locked>> | 96% | 40,872 psi | 64% | 2677 fps | 95.7% |
| Hodgdon H380 | <<locked>> | 80% | 49,879 psi | 78% | 2759 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 41,611 psi | 65% | 2661 fps | 98.1% |
| Hodgdon H4350 | <<locked>> | 80% | 44,556 psi | 70% | 2680 fps | 97.6% |
| Hodgdon H4831 | <<locked>> | 90% | 44,672 psi | 70% | 2707 fps | 95.3% |
| Hodgdon H4831 SC | <<locked>> | 90% | 43,859 psi | 69% | 2690 fps | 95.1% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 35,926 psi | 56% | 2510 fps | 99.8% |
| Hodgdon Retumbo | <<locked>> | 94% | 38,014 psi | 60% | 2710 fps | 96.2% |
| Hodgdon Superformance | <<locked>> | 80% | 40,625 psi | 64% | 2677 fps | 97.6% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,253 psi | 43% | 1575 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 51,039 psi | 80% | 2736 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 53,185 psi | 83% | 2772 fps | 99.6% |
| IMR 4350 | <<locked>> | 80% | 39,015 psi | 61% | 2552 fps | 96.9% |
| IMR 4451 Enduron | <<locked>> | 80% | 44,802 psi | 70% | 2651 fps | 98.6% |
| IMR 4831 | <<locked>> | 80% | 37,927 psi | 59% | 2562 fps | 99.3% |
| IMR 4895 | <<locked>> | 80% | 53,809 psi | 84% | 2825 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 88% | 43,642 psi | 68% | 2651 fps | 95.2% |
| IMR 7828 SSC | <<locked>> | 92% | 42,728 psi | 67% | 2733 fps | 95.5% |
| Lovex S062 | <<locked>> | 80% | 51,111 psi | 80% | 2730 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 42,192 psi | 66% | 2602 fps | 99.1% |
| Lovex S070 | <<locked>> | 80% | 40,451 psi | 63% | 2585 fps | 98% |
| Lovex S071 | <<locked>> | 86% | 30,240 psi | 47% | 2382 fps | 95.4% |
| Norma 203B | <<locked>> | 80% | 51,764 psi | 81% | 2782 fps | 100% |
| Norma 204 | <<locked>> | 80% | 38,595 psi | 60% | 2582 fps | 95.4% |
| Norma MRP | 77.6 gr | 82% | 32,663 psi | 51% | 2530 fps | 95% |
| Norma URP | <<locked>> | 80% | 39,291 psi | 62% | 2605 fps | 99.4% |
| Ramshot Big Game | <<locked>> | 80% | 52,431 psi | 82% | 2808 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 42,351 psi | 66% | 2740 fps | 95.8% |
| Ramshot Hunter | <<locked>> | 80% | 38,218 psi | 60% | 2595 fps | 98% |
| Ramshot Magnum | <<locked>> | 90% | 34,896 psi | 55% | 2552 fps | 95.2% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,804 psi | 44% | 1614 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 49,777 psi | 78% | 2743 fps | 99.6% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 46,862 psi | 73% | 2792 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 39,494 psi | 62% | 2631 fps | 99.3% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 38,101 psi | 60% | 2641 fps | 99% |
| ReloadSwiss RS 76 | <<locked>> | 92% | 34,708 psi | 54% | 2621 fps | 96% |
| Rottweil R 902 | <<locked>> | 80% | 52,881 psi | 83% | 2740 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 46,572 psi | 73% | 2687 fps | 100% |
| Rottweil R 904 | <<locked>> | 86% | 42,598 psi | 67% | 2638 fps | 95.6% |
| Rottweil R 905 | <<locked>> | 84% | 37,260 psi | 58% | 2575 fps | 95.4% |
| Rottweil R 907 | <<locked>> | 80% | 43,410 psi | 68% | 2625 fps | 97.9% |
| Shooters World Long Rifle | <<locked>> | 80% | 42,192 psi | 66% | 2602 fps | 99.1% |
| Shooters World Precision | <<locked>> | 80% | 51,111 psi | 80% | 2730 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 40,451 psi | 63% | 2585 fps | 98% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 48,095 psi | 75% | 2746 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 47,761 psi | 75% | 2585 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 41,365 psi | 65% | 2549 fps | 98% |
| SNPE Vectan Tubal 8000 | <<locked>> | 84% | 36,927 psi | 58% | 2569 fps | 95.3% |
| Somchem S355 | <<locked>> | 80% | 46,760 psi | 73% | 2684 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 46,427 psi | 73% | 2684 fps | 95.8% |
| Somchem S365 | <<locked>> | 80% | 35,853 psi | 56% | 2559 fps | 100% |
| Somchem S385 | <<locked>> | 82% | 35,244 psi | 55% | 2500 fps | 95.6% |
| Vihtavuori N135 | <<locked>> | 80% | 53,534 psi | 84% | 2697 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 53,563 psi | 84% | 2713 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 44,730 psi | 70% | 2615 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 40,727 psi | 64% | 2602 fps | 99.5% |
| Vihtavuori N165 | <<locked>> | 86% | 34,896 psi | 55% | 2487 fps | 95% |
| Vihtavuori N540 | <<locked>> | 80% | 51,822 psi | 81% | 2710 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 40,161 psi | 63% | 2605 fps | 99.4% |
| Vihtavuori N555 | <<locked>> | 80% | 31,198 psi | 49% | 2454 fps | 98.1% |
| Vihtavuori N560 | 85.1 gr | 90% | 43,642 psi | 68% | 2766 fps | 95.4% |
| Vihtavuori N565 | <<locked>> | 96% | 42,902 psi | 67% | 2743 fps | 95.5% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 39,769 psi | 62% | 2569 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 41,771 psi | 65% | 2664 fps | 98.1% |
| Winchester StaBALL HD | <<locked>> | 80% | 24,700 psi | 39% | 2362 fps | 97.5% |
| Winchester Supreme 780 | <<locked>> | 86% | 37,014 psi | 58% | 2539 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 92 powders for 8.5 mm Messner Mag. loaded with the .338 | 225gr | Hornady InterLock. Norma MRP delivers the highest muzzle velocity at 3,022 fps; across all powders the maximum-charge window runs from 1,762 fps to 3,022 fps. ADI AR 2225 gives the best case fill at 100 %, and 92 of the 92 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 57–90 %, leaving at least 10 % headroom. The 225.0 gr projectile in 0.338" calls for a 1:16.5 twist; slower twists will usually not stabilise this weight. ADI AR 2225, Alliant Reloder-23, 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. Accurate High Country, Norma MRP, Vihtavuori N560 rank at the top here: for 8.5 mm Messner Mag. with the .338 | 225gr | Hornady InterLock 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.