Load Specifications
Bullet Manufacturer:TWENTY-NINE
Bullet Weight:191 gr
Bullet Diameter:0.338"
Bullet Length:<<locked>>
Caliber:8.5 mm Messner Mag. load data
Case Length (l3):2.508"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:106 Grains of Water
Primer Size:Large Rifle Magnum (LRM)
Barrel Length:25.6"
Max. allowed Pressure:63,817 psi
Recommended Twist Rate:1:12.5
Load data in caliber 8.5 mm Messner Mag. with .338 | 191gr | TWENTY-NINE ERTP bullet and 107 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ReloadSwiss RS 70, Alliant Reloder-16 and Hodgdon Superformance.
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>> | 84% | 54,070 psi | 85% | 2923 fps | 100% |
| Accurate 2700 | <<locked>> | 86% | 55,970 psi | 88% | 2989 fps | 98.2% |
| Accurate 3100ᴾ | <<locked>> | 100% | 48,747 psi | 76% | 2956 fps | 98.6% |
| Accurate 4064 | <<locked>> | 86% | 54,505 psi | 85% | 2979 fps | 100% |
| Accurate 4350 | <<locked>> | 94% | 54,781 psi | 86% | 3081 fps | 99.9% |
| Accurate High Countryᴾ | <<locked>> | 100% | 53,171 psi | 83% | 3156 fps | 96.3% |
| ADI AR 2206H | <<locked>> | 84% | 57,188 psi | 90% | 3058 fps | 100% |
| ADI AR 2208 | <<locked>> | 88% | 54,984 psi | 86% | 3012 fps | 100% |
| ADI AR 2209ᴾ | <<locked>> | 100% | 56,188 psi | 88% | 3117 fps | 97.6% |
| ADI Benchmark 8208 | <<locked>> | 82% | 55,999 psi | 88% | 3002 fps | 100% |
| Alliant AR-Comp | <<locked>> | 82% | 57,740 psi | 90% | 2972 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 86% | 57,711 psi | 90% | 3196 fps | 100% |
| Alliant Power Pro Varmintᴾ | <<locked>> | 100% | 55,854 psi | 88% | 3110 fps | 97.6% |
| Alliant Power Pro Varmintᴾ | <<locked>> | 100% | 55,854 psi | 88% | 3110 fps | 97.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 88% | 55,477 psi | 87% | 3035 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 86% | 55,840 psi | 88% | 3058 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 96% | 55,477 psi | 87% | 3136 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 92% | 57,058 psi | 89% | 3173 fps | 100% |
| Alliant Reloder-19ᴾ | <<locked>> | 100% | 55,027 psi | 86% | 3100 fps | 97.6% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 48,718 psi | 76% | 3038 fps | 96.4% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 45,788 psi | 72% | 2979 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 40,292 psi | 63% | 2884 fps | 97.5% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 52,373 psi | 82% | 3176 fps | 99.9% |
| Baschieri & Pellagri 107 | <<locked>> | 84% | 57,319 psi | 90% | 3077 fps | 100% |
| Bofors RP3 | <<locked>> | 88% | 56,333 psi | 88% | 3051 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 48,718 psi | 76% | 3038 fps | 96.4% |
| Bofors RP7 | <<locked>> | 92% | 55,753 psi | 87% | 3025 fps | 98.4% |
| Hodgdon Benchmark | <<locked>> | 82% | 57,319 psi | 90% | 2979 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 82% | 55,970 psi | 88% | 3035 fps | 100% |
| Hodgdon H380 | <<locked>> | 88% | 56,869 psi | 89% | 3068 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 94% | 57,159 psi | 90% | 3133 fps | 99.1% |
| Hodgdon H4350 | <<locked>> | 92% | 57,246 psi | 90% | 3091 fps | 98.1% |
| Hodgdon H4895 | <<locked>> | 82% | 54,389 psi | 85% | 3015 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 98% | 55,796 psi | 87% | 3054 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 84% | 54,331 psi | 85% | 3051 fps | 100% |
| Hodgdon Superformance | <<locked>> | 94% | 57,740 psi | 90% | 3176 fps | 99% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,114 psi | 57% | 1883 fps | 100% |
| Hodgdon VARGET | <<locked>> | 84% | 55,463 psi | 87% | 3018 fps | 100% |
| IMR 3031 | <<locked>> | 82% | 54,853 psi | 86% | 2995 fps | 100% |
| IMR 4064 | <<locked>> | 86% | 54,462 psi | 85% | 2992 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 86% | 57,305 psi | 90% | 3025 fps | 99% |
| IMR 4350 | <<locked>> | 96% | 56,608 psi | 89% | 3061 fps | 98.6% |
| IMR 4451 Enduron | <<locked>> | 92% | 57,667 psi | 90% | 3061 fps | 99% |
| IMR 4831 | <<locked>> | 96% | 55,274 psi | 87% | 3071 fps | 100% |
| IMR 4895 | <<locked>> | 86% | 57,305 psi | 90% | 3091 fps | 100% |
| IMR 4955 Enduronᴾ | <<locked>> | 100% | 55,782 psi | 87% | 3041 fps | 95.8% |
| IMR 8208 XBR | <<locked>> | 82% | 55,999 psi | 88% | 3002 fps | 100% |
| Lovex D073.6 | <<locked>> | 84% | 57,696 psi | 90% | 3031 fps | 100% |
| Lovex S060 | <<locked>> | 84% | 56,173 psi | 88% | 2979 fps | 100% |
| Lovex S062 | <<locked>> | 86% | 54,418 psi | 85% | 2986 fps | 100% |
| Lovex S065 | <<locked>> | 94% | 57,421 psi | 90% | 3051 fps | 99.7% |
| Lovex S070 | <<locked>> | 94% | 55,158 psi | 86% | 3038 fps | 98.9% |
| Lovex S071ᴾ | <<locked>> | 100% | 40,509 psi | 63% | 2799 fps | 96.8% |
| Norma 201 | <<locked>> | 84% | 55,898 psi | 88% | 3002 fps | 100% |
| Norma 202 | <<locked>> | 84% | 56,565 psi | 89% | 2995 fps | 100% |
| Norma 203B | <<locked>> | 86% | 55,056 psi | 86% | 3045 fps | 100% |
| Norma 204 | <<locked>> | 96% | 57,566 psi | 90% | 3117 fps | 97.7% |
| Norma MRPᴾ | <<locked>> | 100% | 51,517 psi | 81% | 3127 fps | 98.4% |
| Norma URP | <<locked>> | 96% | 57,116 psi | 90% | 3117 fps | 100% |
| Ramshot Big Game | <<locked>> | 86% | 55,825 psi | 87% | 3071 fps | 100% |
| Ramshot Hunter | <<locked>> | 96% | 56,072 psi | 88% | 3120 fps | 99.5% |
| Ramshot TAC | <<locked>> | 82% | 56,202 psi | 88% | 3031 fps | 99.6% |
| Ramshot Wild Boar | <<locked>> | 82% | 56,188 psi | 88% | 3045 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,593 psi | 57% | 1926 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 88% | 56,869 psi | 89% | 3048 fps | 99.3% |
| ReloadSwiss RS 52 | <<locked>> | 84% | 56,623 psi | 89% | 3130 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 90% | 56,492 psi | 89% | 3163 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 94% | 54,534 psi | 85% | 3100 fps | 99.9% |
| ReloadSwiss RS 70 | <<locked>> | 96% | 57,246 psi | 90% | 3192 fps | 100% |
| Rottweil R 901 | <<locked>> | 82% | 56,782 psi | 89% | 2976 fps | 100% |
| Rottweil R 902 | <<locked>> | 86% | 56,608 psi | 89% | 2999 fps | 100% |
| Rottweil R 903 | <<locked>> | 90% | 56,217 psi | 88% | 3045 fps | 100% |
| Rottweil R 904 | <<locked>> | 98% | 54,375 psi | 85% | 3028 fps | 96.1% |
| Rottweil R 905ᴾ | <<locked>> | 100% | 54,273 psi | 85% | 3087 fps | 97.6% |
| Rottweil R 907 | <<locked>> | 92% | 55,753 psi | 87% | 3025 fps | 98.4% |
| Shooters World Long Rifle | <<locked>> | 94% | 57,421 psi | 90% | 3051 fps | 99.7% |
| Shooters World Match Rifle | <<locked>> | 84% | 57,696 psi | 90% | 3031 fps | 100% |
| Shooters World Precision | <<locked>> | 86% | 54,418 psi | 85% | 2986 fps | 100% |
| Shooters World SW4350 | <<locked>> | 94% | 55,158 psi | 86% | 3038 fps | 98.9% |
| SNPE Vectan SP 11 | <<locked>> | 88% | 54,230 psi | 85% | 3051 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 82% | 54,940 psi | 86% | 3009 fps | 99.8% |
| SNPE Vectan SP 9 | <<locked>> | 84% | 55,637 psi | 87% | 3028 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 84% | 56,898 psi | 89% | 2930 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 90% | 57,711 psi | 90% | 2927 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 94% | 57,624 psi | 90% | 3005 fps | 99% |
| SNPE Vectan Tubal 8000ᴾ | <<locked>> | 100% | 53,766 psi | 84% | 3081 fps | 97.4% |
| Somchem S335 | <<locked>> | 84% | 56,521 psi | 89% | 2927 fps | 100% |
| Somchem S341 | <<locked>> | 82% | 54,534 psi | 85% | 2992 fps | 100% |
| Somchem S355 | <<locked>> | 90% | 56,347 psi | 88% | 3041 fps | 100% |
| Somchem S365 | <<locked>> | 98% | 55,970 psi | 88% | 3120 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 54,984 psi | 86% | 3061 fps | 98.3% |
| Vihtavuori N133 | <<locked>> | 84% | 57,319 psi | 90% | 2907 fps | 100% |
| Vihtavuori N135 | <<locked>> | 86% | 56,724 psi | 89% | 2956 fps | 100% |
| Vihtavuori N140 | <<locked>> | 86% | 57,319 psi | 90% | 2976 fps | 100% |
| Vihtavuori N150 | <<locked>> | 90% | 54,128 psi | 85% | 2963 fps | 100% |
| Vihtavuori N160 | <<locked>> | 94% | 55,927 psi | 88% | 3058 fps | 99.9% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 47,282 psi | 74% | 2913 fps | 96.4% |
| Vihtavuori N530 | <<locked>> | 82% | 56,536 psi | 89% | 3005 fps | 100% |
| Vihtavuori N540 | <<locked>> | 86% | 55,390 psi | 87% | 2969 fps | 100% |
| Vihtavuori N550 | <<locked>> | 94% | 55,042 psi | 86% | 3064 fps | 99.9% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 51,169 psi | 80% | 3061 fps | 100% |
| Winchester 6.5 StaBALL | <<locked>> | 94% | 55,724 psi | 87% | 3025 fps | 100% |
| Winchester 748 | <<locked>> | 82% | 56,942 psi | 89% | 3054 fps | 100% |
| Winchester 760 | <<locked>> | 94% | 57,421 psi | 90% | 3136 fps | 99.1% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 41,336 psi | 65% | 3022 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 84% | 55,796 psi | 87% | 3038 fps | 100% |
| Winchester Supreme 780ᴾ | <<locked>> | 100% | 51,459 psi | 81% | 2992 fps | 96.7% |
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% | 47,543 psi | 75% | 2825 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 45,905 psi | 72% | 2812 fps | 96.2% |
| Accurate 3100 | <<locked>> | 92% | 37,028 psi | 58% | 2720 fps | 95.7% |
| Accurate 4064 | <<locked>> | 80% | 44,947 psi | 70% | 2828 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 33,649 psi | 53% | 2661 fps | 96.4% |
| Accurate High Country | <<locked>> | 98% | 49,617 psi | 78% | 3091 fps | 95.4% |
| ADI AR 2206H | <<locked>> | 80% | 50,401 psi | 79% | 2949 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 42,946 psi | 67% | 2795 fps | 99.1% |
| ADI AR 2209 | <<locked>> | 94% | 46,064 psi | 72% | 2933 fps | 95.3% |
| ADI Benchmark 8208 | <<locked>> | 80% | 52,504 psi | 82% | 2949 fps | 100% |
| Alliant AR-Comp | <<locked>> | 80% | 54,056 psi | 85% | 2923 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 46,717 psi | 73% | 3009 fps | 99.7% |
| Alliant Power Pro Varmint | <<locked>> | 94% | 46,050 psi | 72% | 2933 fps | 95.4% |
| Alliant Power Pro Varmint | <<locked>> | 94% | 46,050 psi | 72% | 2933 fps | 95.4% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 43,047 psi | 67% | 2822 fps | 99.8% |
| Alliant Reloder-15 | <<locked>> | 80% | 46,006 psi | 72% | 2890 fps | 99.6% |
| Alliant Reloder-16 | 68.1 gr | 80% | 33,402 psi | 52% | 2674 fps | 96.4% |
| Alliant Reloder-17 | <<locked>> | 80% | 37,608 psi | 59% | 2808 fps | 99.2% |
| Alliant Reloder-19 | <<locked>> | 94% | 45,513 psi | 71% | 2927 fps | 95.3% |
| Alliant Reloder-22 | <<locked>> | 98% | 45,527 psi | 71% | 2972 fps | 95.5% |
| Alliant Reloder-23 | <<locked>> | 84% | 27,572 psi | 43% | 2523 fps | 95.4% |
| Alliant Reloder-25 | <<locked>> | 96% | 35,505 psi | 56% | 2762 fps | 95.6% |
| Alliant Reloder-26 | <<locked>> | 88% | 33,895 psi | 53% | 2769 fps | 95.9% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 50,198 psi | 79% | 2966 fps | 99.7% |
| Bofors RP3 | <<locked>> | 80% | 43,120 psi | 68% | 2828 fps | 99.9% |
| Bofors RP5 | <<locked>> | 98% | 45,527 psi | 71% | 2972 fps | 95.5% |
| Bofors RP7 | <<locked>> | 82% | 40,872 psi | 64% | 2746 fps | 95.1% |
| Hodgdon Benchmark | <<locked>> | 80% | 53,983 psi | 85% | 2930 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 52,214 psi | 82% | 2979 fps | 100% |
| Hodgdon H380 | <<locked>> | 80% | 43,743 psi | 69% | 2838 fps | 98.5% |
| Hodgdon H414 | <<locked>> | 82% | 38,406 psi | 60% | 2772 fps | 95% |
| Hodgdon H4350 | <<locked>> | 84% | 44,237 psi | 69% | 2854 fps | 95.3% |
| Hodgdon H4895 | <<locked>> | 80% | 50,966 psi | 80% | 2963 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 30,937 psi | 48% | 2569 fps | 97.2% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 47,529 psi | 74% | 2940 fps | 100% |
| Hodgdon Superformance | 81.4 gr | 84% | 40,248 psi | 63% | 2841 fps | 95.1% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,934 psi | 42% | 1686 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 48,834 psi | 77% | 2910 fps | 100% |
| IMR 3031 | <<locked>> | 80% | 51,372 psi | 81% | 2946 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 45,092 psi | 71% | 2831 fps | 99.5% |
| IMR 4166 Enduron | <<locked>> | 80% | 47,413 psi | 74% | 2854 fps | 97.4% |
| IMR 4350 | <<locked>> | 86% | 41,350 psi | 65% | 2779 fps | 95.3% |
| IMR 4451 Enduron | <<locked>> | 80% | 39,755 psi | 62% | 2723 fps | 95.2% |
| IMR 4831 | <<locked>> | 80% | 32,634 psi | 51% | 2615 fps | 96% |
| IMR 4895 | <<locked>> | 80% | 47,181 psi | 74% | 2920 fps | 99.9% |
| IMR 4955 Enduron | <<locked>> | 98% | 52,286 psi | 82% | 2982 fps | 95% |
| IMR 8208 XBR | <<locked>> | 80% | 52,504 psi | 82% | 2949 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 50,502 psi | 79% | 2927 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 49,719 psi | 78% | 2874 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 45,179 psi | 71% | 2831 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 37,246 psi | 58% | 2667 fps | 96.1% |
| Lovex S070 | <<locked>> | 82% | 37,797 psi | 59% | 2700 fps | 95% |
| Lovex S071 | <<locked>> | 96% | 35,563 psi | 56% | 2687 fps | 95.2% |
| Norma 201 | <<locked>> | 80% | 49,400 psi | 77% | 2897 fps | 100% |
| Norma 202 | <<locked>> | 80% | 49,951 psi | 78% | 2897 fps | 100% |
| Norma 203B | <<locked>> | 80% | 45,382 psi | 71% | 2877 fps | 99.7% |
| Norma 204 | <<locked>> | 90% | 46,963 psi | 74% | 2930 fps | 95.5% |
| Norma MRP | <<locked>> | 92% | 39,117 psi | 61% | 2864 fps | 95% |
| Norma URP | <<locked>> | 80% | 33,852 psi | 53% | 2661 fps | 96.3% |
| Ramshot Big Game | <<locked>> | 80% | 45,469 psi | 71% | 2897 fps | 99.7% |
| Ramshot Hunter | <<locked>> | 84% | 37,492 psi | 59% | 2759 fps | 95.7% |
| Ramshot TAC | <<locked>> | 80% | 52,576 psi | 82% | 2969 fps | 99.3% |
| Ramshot Wild Boar | <<locked>> | 80% | 52,504 psi | 82% | 2989 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,296 psi | 43% | 1722 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 43,918 psi | 69% | 2818 fps | 97.2% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 49,342 psi | 77% | 3009 fps | 99.8% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 40,001 psi | 63% | 2871 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 33,417 psi | 52% | 2674 fps | 95.9% |
| ReloadSwiss RS 70 | 76.4 gr | 82% | 35,331 psi | 55% | 2743 fps | 95.9% |
| Rottweil R 901 | <<locked>> | 80% | 53,403 psi | 84% | 2927 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 46,992 psi | 74% | 2844 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 40,611 psi | 64% | 2772 fps | 99.5% |
| Rottweil R 904 | <<locked>> | 96% | 50,836 psi | 80% | 2966 fps | 95.3% |
| Rottweil R 905 | <<locked>> | 94% | 44,382 psi | 70% | 2907 fps | 95.2% |
| Rottweil R 907 | <<locked>> | 82% | 40,872 psi | 64% | 2746 fps | 95.1% |
| Shooters World Long Rifle | <<locked>> | 80% | 37,246 psi | 58% | 2667 fps | 96.1% |
| Shooters World Match Rifle | <<locked>> | 80% | 50,502 psi | 79% | 2927 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 45,179 psi | 71% | 2831 fps | 100% |
| Shooters World SW4350 | <<locked>> | 82% | 37,797 psi | 59% | 2700 fps | 95% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 41,568 psi | 65% | 2825 fps | 99.3% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 51,227 psi | 80% | 2946 fps | 99.5% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 48,950 psi | 77% | 2920 fps | 99.9% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 50,314 psi | 79% | 2831 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 42,308 psi | 66% | 2694 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 82% | 38,899 psi | 61% | 2664 fps | 95.2% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 43,990 psi | 69% | 2900 fps | 95.1% |
| Somchem S335 | <<locked>> | 80% | 50,082 psi | 78% | 2831 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 51,082 psi | 80% | 2940 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 41,104 psi | 64% | 2772 fps | 99.5% |
| Somchem S365 | <<locked>> | 80% | 30,400 psi | 48% | 2612 fps | 98.4% |
| Somchem S385 | <<locked>> | 92% | 42,235 psi | 66% | 2828 fps | 95.5% |
| Vihtavuori N133 | <<locked>> | 80% | 50,792 psi | 80% | 2818 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 46,934 psi | 74% | 2812 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 47,398 psi | 74% | 2828 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 39,218 psi | 61% | 2703 fps | 99.8% |
| Vihtavuori N160 | <<locked>> | 80% | 35,114 psi | 55% | 2661 fps | 96.7% |
| Vihtavuori N165 | <<locked>> | 98% | 44,324 psi | 69% | 2858 fps | 95.7% |
| Vihtavuori N530 | <<locked>> | 80% | 52,910 psi | 83% | 2949 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 45,774 psi | 72% | 2822 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 34,751 psi | 54% | 2664 fps | 96.3% |
| Vihtavuori N555 | <<locked>> | 84% | 30,052 psi | 47% | 2605 fps | 95.6% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 34,693 psi | 54% | 2635 fps | 98.6% |
| Winchester 748 | <<locked>> | 80% | 53,301 psi | 84% | 2999 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 38,406 psi | 60% | 2772 fps | 95% |
| Winchester StaBALL HD | <<locked>> | 88% | 27,731 psi | 43% | 2612 fps | 96.3% |
| Winchester StaBALL Match | <<locked>> | 80% | 48,762 psi | 76% | 2927 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 96% | 44,744 psi | 70% | 2871 fps | 95% |
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 107 powders for 8.5 mm Messner Mag. loaded with the .338 | 191gr | TWENTY-NINE ERTP. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 3,196 fps; across all powders the maximum-charge window runs from 1,883 fps to 3,196 fps. Accurate 3100 gives the best case fill at 100 %, and 107 of the 107 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 191.0 gr projectile in 0.338" calls for a 1:12.5 twist; slower twists will usually not stabilise this weight. Accurate 3100, Accurate High Country, ADI AR 2209 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. ReloadSwiss RS 70, Alliant Reloder-16, Hodgdon Superformance rank at the top here: for 8.5 mm Messner Mag. with the .338 | 191gr | TWENTY-NINE ERTP 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.