Load Specifications
Load data in caliber 8.5 mm Messner Mag. with .338 | 210gr | Impala RNFP KO bullet and 87 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Norma MRP, Vihtavuori N560 and Alliant Reloder-26.
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: 25.6"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2700 | <<locked>> | 82% | 56,579 psi | 89% | 2874 fps | 99.2% |
| Accurate 3100 | <<locked>> | 98% | 55,912 psi | 88% | 2936 fps | 99.9% |
| Accurate 4064 | <<locked>> | 82% | 57,551 psi | 90% | 2871 fps | 100% |
| Accurate 4350 | <<locked>> | 88% | 54,375 psi | 85% | 2930 fps | 100% |
| Accurate High Country | <<locked>> | 96% | 56,463 psi | 88% | 3081 fps | 98.1% |
| Accurate MAGPRO | <<locked>> | 98% | 57,276 psi | 90% | 3074 fps | 97% |
| ADI AR 2208 | <<locked>> | 84% | 55,753 psi | 87% | 2887 fps | 100% |
| ADI AR 2209 | <<locked>> | 96% | 57,667 psi | 90% | 3018 fps | 98.9% |
| ADI AR 2213 | <<locked>> | 98% | 55,376 psi | 87% | 3015 fps | 97.5% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 39,117 psi | 61% | 2746 fps | 96.7% |
| Alliant Power Pro Varmint | <<locked>> | 94% | 54,462 psi | 85% | 2963 fps | 98.5% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 57,145 psi | 90% | 2917 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 57,174 psi | 90% | 2936 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 92% | 57,435 psi | 90% | 3025 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 86% | 55,288 psi | 87% | 2999 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 96% | 57,203 psi | 90% | 3009 fps | 98.9% |
| Alliant Reloder-22 | <<locked>> | 98% | 54,882 psi | 86% | 3018 fps | 98.7% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 55,506 psi | 87% | 2995 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 48,515 psi | 76% | 2940 fps | 99.8% |
| Alliant Reloder-26 | <<locked>> | 96% | 55,825 psi | 87% | 3091 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 53,867 psi | 84% | 2999 fps | 98.5% |
| Bofors RP3 | <<locked>> | 82% | 54,926 psi | 86% | 2887 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 44,585 psi | 70% | 2864 fps | 95.9% |
| Bofors RP5 | <<locked>> | 98% | 54,882 psi | 86% | 3018 fps | 98.7% |
| Bofors RP7 | <<locked>> | 88% | 57,101 psi | 89% | 2920 fps | 99.3% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 47,950 psi | 75% | 2871 fps | 96.7% |
| Hodgdon H380 | <<locked>> | 82% | 54,882 psi | 86% | 2900 fps | 100% |
| Hodgdon H414 | <<locked>> | 88% | 55,448 psi | 87% | 2969 fps | 99.5% |
| Hodgdon H4350 | <<locked>> | 86% | 54,897 psi | 86% | 2927 fps | 98.7% |
| Hodgdon H4831 | <<locked>> | 96% | 55,622 psi | 87% | 2956 fps | 96.9% |
| Hodgdon H4831 SC | <<locked>> | 96% | 54,375 psi | 85% | 2936 fps | 96.7% |
| Hodgdon Hybrid 100V | <<locked>> | 92% | 54,737 psi | 86% | 2900 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 47,427 psi | 74% | 2979 fps | 98.1% |
| Hodgdon Superformance | <<locked>> | 88% | 55,506 psi | 87% | 3009 fps | 99.4% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,956 psi | 58% | 1818 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 55,259 psi | 87% | 2867 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 57,493 psi | 90% | 2904 fps | 99.6% |
| IMR 4350 | <<locked>> | 90% | 54,476 psi | 85% | 2900 fps | 99.1% |
| IMR 4451 Enduron | <<locked>> | 86% | 55,042 psi | 86% | 2894 fps | 99.4% |
| IMR 4831 | <<locked>> | 92% | 57,740 psi | 90% | 2966 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 56,956 psi | 89% | 2943 fps | 97.3% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 56,434 psi | 88% | 3045 fps | 97.9% |
| Lovex S062 | <<locked>> | 82% | 56,101 psi | 88% | 2867 fps | 100% |
| Lovex S065 | <<locked>> | 88% | 55,811 psi | 87% | 2894 fps | 99.9% |
| Lovex S070 | <<locked>> | 90% | 57,116 psi | 90% | 2940 fps | 99.7% |
| Lovex S071ᴾ | <<locked>> | 100% | 50,285 psi | 79% | 2851 fps | 99.5% |
| Norma 203B | <<locked>> | 82% | 56,521 psi | 89% | 2923 fps | 100% |
| Norma 204 | <<locked>> | 90% | 55,187 psi | 86% | 2953 fps | 98.4% |
| Norma MRP | <<locked>> | 96% | 54,462 psi | 85% | 3045 fps | 99.5% |
| Norma URP | <<locked>> | 90% | 55,883 psi | 88% | 2959 fps | 100% |
| Ramshot Big Game | <<locked>> | 82% | 57,101 psi | 89% | 2946 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 57,290 psi | 90% | 3068 fps | 98.3% |
| Ramshot Hunter | <<locked>> | 90% | 54,476 psi | 85% | 2959 fps | 99.8% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 51,547 psi | 81% | 2943 fps | 98.8% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,782 psi | 59% | 1864 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 54,520 psi | 85% | 2881 fps | 99.7% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 54,708 psi | 86% | 2989 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 57,232 psi | 90% | 2999 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 55,056 psi | 86% | 3022 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 47,732 psi | 75% | 2979 fps | 99% |
| Rottweil R 903 | <<locked>> | 84% | 55,187 psi | 86% | 2884 fps | 100% |
| Rottweil R 904 | <<locked>> | 94% | 55,854 psi | 88% | 2933 fps | 97.7% |
| Rottweil R 905 | <<locked>> | 96% | 56,637 psi | 89% | 2995 fps | 98.9% |
| Rottweil R 907 | <<locked>> | 88% | 57,101 psi | 89% | 2920 fps | 99.3% |
| Shooters World Long Rifle | <<locked>> | 88% | 55,811 psi | 87% | 2894 fps | 99.9% |
| Shooters World Precision | <<locked>> | 82% | 56,101 psi | 88% | 2867 fps | 100% |
| Shooters World SW4350 | <<locked>> | 90% | 57,116 psi | 90% | 2940 fps | 99.7% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 55,927 psi | 88% | 2936 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 55,129 psi | 86% | 2756 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 55,303 psi | 87% | 2844 fps | 99.4% |
| SNPE Vectan Tubal 8000 | <<locked>> | 96% | 56,144 psi | 88% | 2992 fps | 98.8% |
| Somchem S355 | <<locked>> | 84% | 54,911 psi | 86% | 2877 fps | 100% |
| Somchem S361 | <<locked>> | 94% | 57,682 psi | 90% | 2923 fps | 97.2% |
| Somchem S365 | <<locked>> | 92% | 55,463 psi | 87% | 2963 fps | 100% |
| Somchem S385 | <<locked>> | 96% | 57,551 psi | 90% | 2972 fps | 99.4% |
| Vihtavuori N150 | <<locked>> | 86% | 55,869 psi | 88% | 2848 fps | 100% |
| Vihtavuori N160 | <<locked>> | 88% | 54,317 psi | 85% | 2897 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 56,478 psi | 89% | 2943 fps | 99.1% |
| Vihtavuori N540 | <<locked>> | 82% | 56,507 psi | 89% | 2844 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 56,985 psi | 89% | 2959 fps | 100% |
| Vihtavuori N555 | <<locked>> | 96% | 55,201 psi | 87% | 2979 fps | 100% |
| Vihtavuori N560 | <<locked>> | 96% | 54,578 psi | 86% | 3031 fps | 97.1% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 50,792 psi | 80% | 2949 fps | 96.6% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 57,029 psi | 89% | 2910 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 55,637 psi | 87% | 2976 fps | 99.6% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 51,198 psi | 80% | 3077 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 98% | 57,435 psi | 90% | 2966 fps | 98.8% |
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 2700 | <<locked>> | 80% | 53,098 psi | 83% | 2818 fps | 98.7% |
| Accurate 3100 | <<locked>> | 80% | 31,908 psi | 50% | 2464 fps | 95.2% |
| Accurate 4064 | <<locked>> | 80% | 54,404 psi | 85% | 2825 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 42,076 psi | 66% | 2717 fps | 99.4% |
| Accurate High Country | <<locked>> | 88% | 43,337 psi | 68% | 2838 fps | 95.1% |
| Accurate MAGPRO | <<locked>> | 94% | 50,125 psi | 79% | 2956 fps | 95.5% |
| ADI AR 2208 | <<locked>> | 80% | 49,545 psi | 78% | 2789 fps | 100% |
| ADI AR 2209 | <<locked>> | 86% | 42,322 psi | 66% | 2736 fps | 95.7% |
| ADI AR 2213 | <<locked>> | 92% | 45,861 psi | 72% | 2838 fps | 95.2% |
| ADI AR 2225 | <<locked>> | 98% | 36,927 psi | 58% | 2687 fps | 95.8% |
| Alliant Power Pro Varmint | <<locked>> | 84% | 40,045 psi | 63% | 2684 fps | 95% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 50,633 psi | 79% | 2815 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 53,809 psi | 84% | 2887 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 39,871 psi | 62% | 2710 fps | 99.4% |
| Alliant Reloder-17 | <<locked>> | 80% | 45,208 psi | 71% | 2835 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 84% | 39,682 psi | 62% | 2677 fps | 95% |
| Alliant Reloder-22 | <<locked>> | 88% | 40,030 psi | 63% | 2733 fps | 95.3% |
| Alliant Reloder-23 | <<locked>> | 80% | 30,414 psi | 48% | 2493 fps | 98.3% |
| Alliant Reloder-25 | <<locked>> | 86% | 32,068 psi | 50% | 2552 fps | 95.7% |
| Alliant Reloder-26 | 77.1 gr | 80% | 32,460 psi | 51% | 2608 fps | 96.9% |
| Bofors RP15 | <<locked>> | 90% | 39,668 psi | 62% | 2720 fps | 95% |
| Bofors RP3 | <<locked>> | 80% | 51,663 psi | 81% | 2838 fps | 100% |
| Bofors RP30 | <<locked>> | 98% | 41,916 psi | 66% | 2805 fps | 95% |
| Bofors RP5 | <<locked>> | 88% | 40,030 psi | 63% | 2733 fps | 95.3% |
| Bofors RP7 | <<locked>> | 80% | 45,121 psi | 71% | 2710 fps | 97.6% |
| Hodgdon H1000 | <<locked>> | 98% | 44,991 psi | 71% | 2812 fps | 95.8% |
| Hodgdon H380 | <<locked>> | 80% | 51,605 psi | 81% | 2848 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 80% | 43,236 psi | 68% | 2749 fps | 97.7% |
| Hodgdon H4350 | <<locked>> | 80% | 45,788 psi | 72% | 2762 fps | 97.1% |
| Hodgdon H4831 | <<locked>> | 92% | 48,805 psi | 76% | 2841 fps | 95.4% |
| Hodgdon H4831 SC | <<locked>> | 92% | 47,964 psi | 75% | 2825 fps | 95.2% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 37,811 psi | 59% | 2605 fps | 99.7% |
| Hodgdon Retumbo | <<locked>> | 94% | 39,610 psi | 62% | 2795 fps | 95.5% |
| Hodgdon Superformance | <<locked>> | 80% | 42,032 psi | 66% | 2762 fps | 97.1% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,833 psi | 44% | 1627 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 52,141 psi | 82% | 2818 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 54,172 psi | 85% | 2851 fps | 99.3% |
| IMR 4350 | <<locked>> | 80% | 40,466 psi | 63% | 2638 fps | 96.4% |
| IMR 4451 Enduron | <<locked>> | 80% | 46,122 psi | 72% | 2733 fps | 98.1% |
| IMR 4831 | <<locked>> | 80% | 39,972 psi | 63% | 2657 fps | 99.1% |
| IMR 4955 Enduron | <<locked>> | 90% | 47,572 psi | 75% | 2782 fps | 95.3% |
| IMR 7828 SSC | <<locked>> | 94% | 46,731 psi | 73% | 2871 fps | 95.6% |
| Lovex S062 | <<locked>> | 80% | 52,968 psi | 83% | 2822 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 44,251 psi | 69% | 2694 fps | 98.9% |
| Lovex S070 | <<locked>> | 80% | 42,511 psi | 67% | 2677 fps | 97.7% |
| Lovex S071 | <<locked>> | 86% | 33,272 psi | 52% | 2500 fps | 95.7% |
| Norma 203B | <<locked>> | 80% | 53,243 psi | 83% | 2874 fps | 100% |
| Norma 204 | <<locked>> | 82% | 42,714 psi | 67% | 2723 fps | 95.7% |
| Norma MRP | 78.6 gr | 84% | 36,970 psi | 58% | 2690 fps | 95.8% |
| Norma URP | <<locked>> | 80% | 41,060 psi | 64% | 2697 fps | 99.2% |
| Ramshot Big Game | <<locked>> | 80% | 53,577 psi | 84% | 2894 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 43,714 psi | 69% | 2818 fps | 95% |
| Ramshot Hunter | <<locked>> | 80% | 39,827 psi | 62% | 2687 fps | 97.7% |
| Ramshot Magnum | <<locked>> | 92% | 39,291 psi | 62% | 2703 fps | 95.7% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,340 psi | 44% | 1663 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 51,184 psi | 80% | 2828 fps | 99.4% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 47,790 psi | 75% | 2881 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 41,350 psi | 65% | 2726 fps | 99.1% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 39,726 psi | 62% | 2733 fps | 98.7% |
| ReloadSwiss RS 76 | <<locked>> | 92% | 36,695 psi | 57% | 2717 fps | 95.5% |
| Rottweil R 903 | <<locked>> | 80% | 48,791 psi | 76% | 2782 fps | 100% |
| Rottweil R 904 | <<locked>> | 88% | 46,586 psi | 73% | 2769 fps | 95.7% |
| Rottweil R 905 | <<locked>> | 86% | 41,466 psi | 65% | 2720 fps | 95.8% |
| Rottweil R 907 | <<locked>> | 80% | 45,121 psi | 71% | 2710 fps | 97.6% |
| Shooters World Long Rifle | <<locked>> | 80% | 44,251 psi | 69% | 2694 fps | 98.9% |
| Shooters World Precision | <<locked>> | 80% | 52,968 psi | 83% | 2822 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 42,511 psi | 67% | 2677 fps | 97.7% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 49,356 psi | 77% | 2835 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 48,994 psi | 77% | 2667 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 43,366 psi | 68% | 2638 fps | 97.7% |
| SNPE Vectan Tubal 8000 | <<locked>> | 86% | 41,075 psi | 64% | 2713 fps | 95.7% |
| Somchem S355 | <<locked>> | 80% | 48,791 psi | 76% | 2779 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 47,645 psi | 75% | 2756 fps | 95% |
| Somchem S365 | <<locked>> | 80% | 37,739 psi | 59% | 2661 fps | 100% |
| Somchem S385 | <<locked>> | 82% | 37,478 psi | 59% | 2598 fps | 95.4% |
| Vihtavuori N150 | <<locked>> | 80% | 46,470 psi | 73% | 2703 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 42,395 psi | 66% | 2690 fps | 99.3% |
| Vihtavuori N165 | <<locked>> | 88% | 38,986 psi | 61% | 2628 fps | 95.5% |
| Vihtavuori N540 | <<locked>> | 80% | 53,243 psi | 83% | 2799 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 42,090 psi | 66% | 2697 fps | 99.2% |
| Vihtavuori N555 | <<locked>> | 80% | 33,779 psi | 53% | 2569 fps | 98.2% |
| Vihtavuori N560 | 86.1 gr | 92% | 48,066 psi | 75% | 2913 fps | 95.6% |
| Vihtavuori N565 | <<locked>> | 96% | 44,657 psi | 70% | 2835 fps | 95% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 41,278 psi | 65% | 2657 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 43,337 psi | 68% | 2753 fps | 97.8% |
| Winchester StaBALL HD | <<locked>> | 80% | 27,296 psi | 43% | 2490 fps | 97.9% |
| Winchester Supreme 780 | <<locked>> | 88% | 41,365 psi | 65% | 2684 fps | 95.5% |
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 87 powders for 8.5 mm Messner Mag. loaded with the .338 | 210gr | Impala RNFP KO. Alliant Reloder-26 delivers the highest muzzle velocity at 3,091 fps; across all powders the maximum-charge window runs from 1,818 fps to 3,091 fps. ADI AR 2225 gives the best case fill at 100 %, and 87 of the 87 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 210.0 gr projectile in 0.338" calls for a 1:15.0 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. Norma MRP, Vihtavuori N560, Alliant Reloder-26 rank at the top here: for 8.5 mm Messner Mag. with the .338 | 210gr | Impala RNFP KO 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.