Load Specifications
Bullet Manufacturer:TWENTY-NINE
Bullet Weight:226 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:1:16.5
Load data in caliber 8.5 mm Messner Mag. with .338 | 226gr | TWENTY-NINE SILENTIO bullet and 92 powders. The key underlying parameters are shown in the table above.
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 2700 | <<locked>> | 82% | 55,187 psi | 86% | 2769 fps | 99.4% |
| Accurate 3100ᴾ | <<locked>> | 100% | 57,609 psi | 90% | 2877 fps | 100% |
| Accurate 4064 | <<locked>> | 82% | 54,969 psi | 86% | 2749 fps | 100% |
| Accurate 4350 | <<locked>> | 90% | 55,869 psi | 88% | 2867 fps | 100% |
| Accurate High Country | <<locked>> | 96% | 55,100 psi | 86% | 2972 fps | 98.5% |
| Accurate MAGPRO | <<locked>> | 98% | 56,014 psi | 88% | 2972 fps | 97.5% |
| ADI AR 2208 | <<locked>> | 84% | 54,766 psi | 86% | 2782 fps | 100% |
| ADI AR 2209 | <<locked>> | 96% | 56,797 psi | 89% | 2920 fps | 99.2% |
| ADI AR 2213 | <<locked>> | 98% | 54,288 psi | 85% | 2913 fps | 98% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 37,434 psi | 59% | 2641 fps | 97.1% |
| Alliant Power Pro Varmint | <<locked>> | 96% | 56,840 psi | 89% | 2913 fps | 99.2% |
| Alliant Power Pro Varmint | <<locked>> | 96% | 56,840 psi | 89% | 2913 fps | 99.2% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 55,593 psi | 87% | 2805 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 55,869 psi | 88% | 2828 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 92% | 56,652 psi | 89% | 2920 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 86% | 54,143 psi | 85% | 2887 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 96% | 56,072 psi | 88% | 2904 fps | 99.2% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 57,334 psi | 90% | 2969 fps | 99.4% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 54,230 psi | 85% | 2887 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 47,137 psi | 74% | 2835 fps | 99.9% |
| Alliant Reloder-26 | <<locked>> | 96% | 54,534 psi | 85% | 2979 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 52,576 psi | 82% | 2894 fps | 98.8% |
| Bofors RP3 | <<locked>> | 84% | 56,739 psi | 89% | 2825 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 42,859 psi | 67% | 2756 fps | 96.3% |
| Bofors RP5ᴾ | <<locked>> | 100% | 57,334 psi | 90% | 2969 fps | 99.4% |
| Bofors RP7 | <<locked>> | 88% | 55,695 psi | 87% | 2815 fps | 99.6% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 46,601 psi | 73% | 2772 fps | 97.2% |
| Hodgdon H380 | <<locked>> | 84% | 56,956 psi | 89% | 2844 fps | 100% |
| Hodgdon H414 | <<locked>> | 88% | 54,331 psi | 85% | 2867 fps | 99.7% |
| Hodgdon H4350 | <<locked>> | 88% | 57,435 psi | 90% | 2877 fps | 99.4% |
| Hodgdon H4831 | <<locked>> | 96% | 54,491 psi | 85% | 2858 fps | 97.4% |
| Hodgdon H4831 SC | <<locked>> | 98% | 57,000 psi | 89% | 2897 fps | 97.9% |
| Hodgdon Hybrid 100V | <<locked>> | 94% | 57,101 psi | 89% | 2841 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 46,035 psi | 72% | 2874 fps | 98.6% |
| Hodgdon Superformance | <<locked>> | 88% | 54,389 psi | 85% | 2904 fps | 99.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,724 psi | 58% | 1749 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 57,682 psi | 90% | 2815 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 56,565 psi | 89% | 2802 fps | 99.8% |
| IMR 4350 | <<locked>> | 92% | 57,014 psi | 89% | 2854 fps | 99.7% |
| IMR 4451 Enduron | <<locked>> | 88% | 57,232 psi | 90% | 2838 fps | 99.8% |
| IMR 4831 | <<locked>> | 92% | 56,376 psi | 88% | 2858 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 57,305 psi | 90% | 2854 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 56,072 psi | 88% | 2844 fps | 97.8% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 55,477 psi | 87% | 2946 fps | 98.3% |
| Lovex S062 | <<locked>> | 82% | 54,462 psi | 85% | 2756 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 57,595 psi | 90% | 2838 fps | 100% |
| Lovex S070 | <<locked>> | 90% | 55,608 psi | 87% | 2831 fps | 99.8% |
| Lovex S071ᴾ | <<locked>> | 100% | 48,095 psi | 75% | 2736 fps | 99.6% |
| Norma 203B | <<locked>> | 82% | 55,158 psi | 86% | 2815 fps | 100% |
| Norma 204 | <<locked>> | 90% | 54,085 psi | 85% | 2851 fps | 98.8% |
| Norma MRP | <<locked>> | 98% | 57,043 psi | 89% | 2992 fps | 99.9% |
| Norma URP | <<locked>> | 90% | 54,549 psi | 85% | 2851 fps | 100% |
| Ramshot Big Game | <<locked>> | 82% | 55,956 psi | 88% | 2841 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 56,115 psi | 88% | 2966 fps | 98.7% |
| Ramshot Hunter | <<locked>> | 92% | 56,840 psi | 89% | 2907 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 50,169 psi | 79% | 2841 fps | 99.1% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,318 psi | 58% | 1788 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 56,623 psi | 89% | 2828 fps | 99.9% |
| ReloadSwiss RS 60 | <<locked>> | 86% | 57,493 psi | 90% | 2930 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 55,738 psi | 87% | 2890 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 54,056 psi | 85% | 2920 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 46,035 psi | 72% | 2871 fps | 99.3% |
| Rottweil R 902 | <<locked>> | 82% | 56,391 psi | 88% | 2769 fps | 100% |
| Rottweil R 903 | <<locked>> | 86% | 56,768 psi | 89% | 2818 fps | 100% |
| Rottweil R 904 | <<locked>> | 94% | 54,795 psi | 86% | 2831 fps | 98.1% |
| Rottweil R 905 | <<locked>> | 96% | 55,492 psi | 87% | 2894 fps | 99.2% |
| Rottweil R 907 | <<locked>> | 88% | 55,695 psi | 87% | 2815 fps | 99.6% |
| Shooters World Long Rifle | <<locked>> | 90% | 57,595 psi | 90% | 2838 fps | 100% |
| Shooters World Precision | <<locked>> | 82% | 54,462 psi | 85% | 2756 fps | 100% |
| Shooters World SW4350 | <<locked>> | 90% | 55,608 psi | 87% | 2831 fps | 99.8% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 54,737 psi | 86% | 2828 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 57,319 psi | 90% | 2694 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 57,217 psi | 90% | 2792 fps | 99.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 96% | 55,027 psi | 86% | 2890 fps | 99.1% |
| Somchem S355 | <<locked>> | 86% | 56,652 psi | 89% | 2815 fps | 100% |
| Somchem S361 | <<locked>> | 94% | 56,507 psi | 89% | 2825 fps | 97.7% |
| Somchem S365 | <<locked>> | 92% | 54,215 psi | 85% | 2854 fps | 100% |
| Somchem S385 | <<locked>> | 96% | 55,970 psi | 88% | 2864 fps | 99.6% |
| Vihtavuori N135 | <<locked>> | 82% | 56,971 psi | 89% | 2723 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 56,971 psi | 89% | 2740 fps | 100% |
| Vihtavuori N150 | <<locked>> | 86% | 54,360 psi | 85% | 2740 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 56,478 psi | 89% | 2841 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 55,274 psi | 87% | 2841 fps | 99.4% |
| Vihtavuori N540 | <<locked>> | 82% | 55,216 psi | 87% | 2740 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 55,753 psi | 87% | 2851 fps | 100% |
| Vihtavuori N555 | <<locked>> | 98% | 56,913 psi | 89% | 2917 fps | 100% |
| Vihtavuori N560 | <<locked>> | 98% | 57,116 psi | 90% | 2986 fps | 98.2% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 48,979 psi | 77% | 2838 fps | 97% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 56,130 psi | 88% | 2808 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 54,520 psi | 85% | 2871 fps | 99.8% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 49,995 psi | 78% | 2963 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 98% | 56,014 psi | 88% | 2861 fps | 99.1% |
Start Load - Barrel Length: 25.6"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2700 | <<locked>> | 80% | 51,779 psi | 81% | 2717 fps | 99% |
| Accurate 3100 | <<locked>> | 82% | 31,430 psi | 49% | 2395 fps | 95.8% |
| Accurate 4064 | <<locked>> | 80% | 51,692 psi | 81% | 2703 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 39,769 psi | 62% | 2595 fps | 99.4% |
| Accurate High Country | <<locked>> | 88% | 41,655 psi | 65% | 2726 fps | 95.4% |
| Accurate MAGPRO | <<locked>> | 92% | 45,324 psi | 71% | 2785 fps | 95% |
| ADI AR 2208 | <<locked>> | 80% | 48,457 psi | 76% | 2687 fps | 100% |
| ADI AR 2209 | <<locked>> | 84% | 38,421 psi | 60% | 2579 fps | 95.3% |
| ADI AR 2213 | <<locked>> | 92% | 44,512 psi | 70% | 2736 fps | 95.8% |
| ADI AR 2225 | <<locked>> | 98% | 35,114 psi | 55% | 2579 fps | 96.1% |
| Alliant Power Pro Varmint | <<locked>> | 84% | 38,595 psi | 60% | 2582 fps | 95.4% |
| Alliant Power Pro Varmint | <<locked>> | 84% | 38,595 psi | 60% | 2582 fps | 95.4% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 49,182 psi | 77% | 2710 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 52,359 psi | 82% | 2776 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 38,508 psi | 60% | 2605 fps | 99.5% |
| Alliant Reloder-17 | <<locked>> | 80% | 43,874 psi | 69% | 2726 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 84% | 38,203 psi | 60% | 2575 fps | 95.4% |
| Alliant Reloder-22 | <<locked>> | 88% | 38,406 psi | 60% | 2625 fps | 95.6% |
| Alliant Reloder-23 | <<locked>> | 80% | 28,384 psi | 44% | 2375 fps | 98.2% |
| Alliant Reloder-25 | <<locked>> | 86% | 30,153 psi | 47% | 2438 fps | 95.7% |
| Alliant Reloder-26 | <<locked>> | 80% | 30,342 psi | 48% | 2487 fps | 96.8% |
| Bofors RP15 | <<locked>> | 90% | 38,029 psi | 60% | 2615 fps | 95.3% |
| Bofors RP3 | <<locked>> | 80% | 49,661 psi | 78% | 2720 fps | 100% |
| Bofors RP30 | <<locked>> | 98% | 40,219 psi | 63% | 2697 fps | 95.4% |
| Bofors RP5 | <<locked>> | 88% | 38,406 psi | 60% | 2625 fps | 95.6% |
| Bofors RP7 | <<locked>> | 80% | 43,453 psi | 68% | 2605 fps | 97.8% |
| Hodgdon H1000 | <<locked>> | 96% | 40,683 psi | 64% | 2651 fps | 95.4% |
| Hodgdon H380 | <<locked>> | 80% | 49,966 psi | 78% | 2740 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 41,684 psi | 65% | 2644 fps | 98% |
| Hodgdon H4350 | <<locked>> | 80% | 44,498 psi | 70% | 2661 fps | 97.5% |
| Hodgdon H4831 | <<locked>> | 90% | 44,469 psi | 70% | 2684 fps | 95.1% |
| Hodgdon H4831 SC | <<locked>> | 92% | 46,702 psi | 73% | 2726 fps | 95.7% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 36,056 psi | 56% | 2497 fps | 99.8% |
| Hodgdon Retumbo | <<locked>> | 94% | 37,956 psi | 59% | 2687 fps | 95.9% |
| Hodgdon Superformance | <<locked>> | 80% | 40,582 psi | 64% | 2657 fps | 97.5% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,369 psi | 43% | 1562 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 50,995 psi | 80% | 2717 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 53,069 psi | 83% | 2749 fps | 99.6% |
| IMR 4350 | <<locked>> | 80% | 39,131 psi | 61% | 2536 fps | 96.8% |
| IMR 4451 Enduron | <<locked>> | 80% | 44,889 psi | 70% | 2635 fps | 98.5% |
| IMR 4831 | <<locked>> | 80% | 38,189 psi | 60% | 2549 fps | 99.2% |
| IMR 4895 | <<locked>> | 80% | 53,737 psi | 84% | 2802 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 88% | 43,685 psi | 68% | 2631 fps | 95.1% |
| IMR 7828 SSC | <<locked>> | 92% | 42,641 psi | 67% | 2710 fps | 95.3% |
| Lovex S062 | <<locked>> | 80% | 51,227 psi | 80% | 2710 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 42,438 psi | 67% | 2585 fps | 99% |
| Lovex S070 | <<locked>> | 80% | 40,712 psi | 64% | 2572 fps | 97.9% |
| Lovex S071 | <<locked>> | 86% | 30,690 psi | 48% | 2375 fps | 95.5% |
| Norma 203B | <<locked>> | 80% | 51,721 psi | 81% | 2762 fps | 100% |
| Norma 204 | <<locked>> | 80% | 38,522 psi | 60% | 2562 fps | 95.2% |
| Norma MRP | <<locked>> | 84% | 35,128 psi | 55% | 2579 fps | 96% |
| Norma URP | <<locked>> | 80% | 39,465 psi | 62% | 2589 fps | 99.3% |
| Ramshot Big Game | <<locked>> | 80% | 52,257 psi | 82% | 2785 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 42,206 psi | 66% | 2717 fps | 95.6% |
| Ramshot Hunter | <<locked>> | 80% | 38,174 psi | 60% | 2579 fps | 97.9% |
| Ramshot Magnum | <<locked>> | 90% | 34,969 psi | 55% | 2533 fps | 95% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,978 psi | 44% | 1601 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 49,821 psi | 78% | 2723 fps | 99.6% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 46,615 psi | 73% | 2772 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 39,552 psi | 62% | 2615 fps | 99.3% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 38,130 psi | 60% | 2625 fps | 98.9% |
| ReloadSwiss RS 76 | <<locked>> | 92% | 34,925 psi | 55% | 2608 fps | 95.8% |
| Rottweil R 902 | <<locked>> | 80% | 53,026 psi | 83% | 2720 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 46,862 psi | 73% | 2671 fps | 100% |
| Rottweil R 904 | <<locked>> | 86% | 42,380 psi | 66% | 2612 fps | 95.3% |
| Rottweil R 905 | <<locked>> | 84% | 37,289 psi | 58% | 2559 fps | 95.3% |
| Rottweil R 907 | <<locked>> | 80% | 43,453 psi | 68% | 2605 fps | 97.8% |
| Shooters World Long Rifle | <<locked>> | 80% | 42,438 psi | 67% | 2585 fps | 99% |
| Shooters World Precision | <<locked>> | 80% | 51,227 psi | 80% | 2710 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 40,712 psi | 64% | 2572 fps | 97.9% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 47,863 psi | 75% | 2723 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 47,688 psi | 75% | 2566 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 41,524 psi | 65% | 2533 fps | 97.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 84% | 36,941 psi | 58% | 2552 fps | 95.1% |
| Somchem S355 | <<locked>> | 80% | 46,934 psi | 74% | 2667 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 46,253 psi | 72% | 2657 fps | 95.5% |
| Somchem S365 | <<locked>> | 80% | 36,027 psi | 56% | 2549 fps | 100% |
| Somchem S385 | <<locked>> | 82% | 35,549 psi | 56% | 2490 fps | 95.6% |
| Vihtavuori N135 | <<locked>> | 80% | 53,490 psi | 84% | 2677 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 53,592 psi | 84% | 2694 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 44,918 psi | 70% | 2598 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 40,770 psi | 64% | 2585 fps | 99.5% |
| Vihtavuori N165 | <<locked>> | 88% | 37,362 psi | 59% | 2523 fps | 95.8% |
| Vihtavuori N540 | <<locked>> | 80% | 51,808 psi | 81% | 2694 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 40,292 psi | 63% | 2589 fps | 99.3% |
| Vihtavuori N555 | <<locked>> | 80% | 31,575 psi | 49% | 2448 fps | 98.2% |
| Vihtavuori N560 | <<locked>> | 90% | 43,555 psi | 68% | 2746 fps | 95.2% |
| Vihtavuori N565 | <<locked>> | 96% | 42,757 psi | 67% | 2723 fps | 95.3% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 39,827 psi | 62% | 2552 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 41,684 psi | 65% | 2644 fps | 98% |
| Winchester StaBALL HD | <<locked>> | 80% | 25,048 psi | 39% | 2356 fps | 97.6% |
| Winchester Supreme 780 | <<locked>> | 88% | 39,653 psi | 62% | 2579 fps | 95.8% |
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 | 226gr | TWENTY-NINE SILENTIO. Norma MRP delivers the highest muzzle velocity at 2,992 fps; across all powders the maximum-charge window runs from 1,749 fps to 2,992 fps. Accurate 3100 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 58–90 %, leaving at least 10 % headroom. The 226.0 gr projectile in 0.338" calls for a 1:16.5 twist; slower twists will usually not stabilise this weight. Accurate 3100, ADI AR 2225, Alliant Reloder-22 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. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.