Load Specifications
Bullet Manufacturer:Barnes
Bullet Weight:225 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 | 225gr | Barnes TTSX BT bullet and 103 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-26 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% | 57,217 psi | 90% | 2730 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 55,608 psi | 87% | 2769 fps | 99.2% |
| Accurate 3100ᴾ | <<locked>> | 100% | 52,881 psi | 83% | 2808 fps | 99.8% |
| Accurate 4064 | <<locked>> | 84% | 54,128 psi | 85% | 2743 fps | 100% |
| Accurate 4350 | <<locked>> | 92% | 55,100 psi | 86% | 2854 fps | 100% |
| Accurate MAGPROᴾ | <<locked>> | 100% | 55,259 psi | 87% | 2956 fps | 97% |
| ADI AR 2206H | <<locked>> | 82% | 57,101 psi | 89% | 2825 fps | 100% |
| ADI AR 2208 | <<locked>> | 86% | 54,795 psi | 86% | 2779 fps | 100% |
| ADI AR 2209 | <<locked>> | 98% | 56,347 psi | 88% | 2904 fps | 98.9% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 54,056 psi | 85% | 2900 fps | 97.6% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 54,085 psi | 85% | 2904 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 55,564 psi | 87% | 2802 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 84% | 55,782 psi | 87% | 2825 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 94% | 56,101 psi | 88% | 2910 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 88% | 53,751 psi | 84% | 2884 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 98% | 55,709 psi | 87% | 2894 fps | 98.9% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 52,808 psi | 83% | 2897 fps | 98.7% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 49,734 psi | 78% | 2825 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 43,236 psi | 68% | 2756 fps | 99.5% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 57,595 psi | 90% | 3025 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 82% | 57,305 psi | 90% | 2848 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 48,399 psi | 76% | 2822 fps | 97.8% |
| Bofors RP3 | <<locked>> | 86% | 56,362 psi | 88% | 2818 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 52,808 psi | 83% | 2897 fps | 98.7% |
| Bofors RP7 | <<locked>> | 90% | 55,651 psi | 87% | 2808 fps | 99.4% |
| Hodgdon H380 | <<locked>> | 86% | 56,681 psi | 89% | 2838 fps | 100% |
| Hodgdon H414 | <<locked>> | 90% | 53,911 psi | 84% | 2858 fps | 99.6% |
| Hodgdon H4350 | <<locked>> | 90% | 57,508 psi | 90% | 2874 fps | 99.2% |
| Hodgdon H4831 | <<locked>> | 98% | 54,128 psi | 85% | 2844 fps | 97% |
| Hodgdon H4831 SCᴾ | <<locked>> | 100% | 56,840 psi | 89% | 2887 fps | 97.5% |
| Hodgdon H4895 | <<locked>> | 82% | 57,740 psi | 90% | 2831 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 56,550 psi | 89% | 2835 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 54,505 psi | 85% | 2822 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 42,293 psi | 66% | 2785 fps | 97.1% |
| Hodgdon Superformance | <<locked>> | 90% | 54,085 psi | 85% | 2897 fps | 99.5% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,303 psi | 57% | 1729 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 55,332 psi | 87% | 2785 fps | 100% |
| IMR 4064 | <<locked>> | 86% | 57,711 psi | 90% | 2812 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 84% | 57,029 psi | 89% | 2802 fps | 99.7% |
| IMR 4350 | <<locked>> | 94% | 56,826 psi | 89% | 2844 fps | 99.5% |
| IMR 4451 Enduron | <<locked>> | 90% | 57,450 psi | 90% | 2835 fps | 99.7% |
| IMR 4831 | <<locked>> | 94% | 55,695 psi | 87% | 2848 fps | 100% |
| IMR 4895 | <<locked>> | 84% | 57,276 psi | 90% | 2854 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 98% | 55,767 psi | 87% | 2831 fps | 97.5% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 51,343 psi | 80% | 2871 fps | 97.2% |
| Lovex D073.6 | <<locked>> | 82% | 57,522 psi | 90% | 2792 fps | 100% |
| Lovex S060 | <<locked>> | 82% | 55,854 psi | 88% | 2746 fps | 100% |
| Lovex S062 | <<locked>> | 84% | 54,447 psi | 85% | 2756 fps | 100% |
| Lovex S065 | <<locked>> | 92% | 57,319 psi | 90% | 2828 fps | 100% |
| Lovex S070 | <<locked>> | 92% | 55,230 psi | 87% | 2825 fps | 99.7% |
| Lovex S071ᴾ | <<locked>> | 100% | 43,729 psi | 69% | 2661 fps | 98.9% |
| Norma 201 | <<locked>> | 82% | 55,637 psi | 87% | 2766 fps | 100% |
| Norma 202 | <<locked>> | 82% | 56,521 psi | 89% | 2759 fps | 100% |
| Norma 203B | <<locked>> | 84% | 55,071 psi | 86% | 2812 fps | 100% |
| Norma 204 | <<locked>> | 92% | 54,041 psi | 85% | 2844 fps | 98.5% |
| Norma MRPᴾ | <<locked>> | 100% | 56,101 psi | 88% | 2979 fps | 99.8% |
| Norma URP | <<locked>> | 92% | 54,070 psi | 85% | 2844 fps | 100% |
| Ramshot Big Game | <<locked>> | 84% | 55,927 psi | 88% | 2838 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 51,648 psi | 81% | 2887 fps | 97.6% |
| Ramshot Hunter | <<locked>> | 94% | 56,507 psi | 89% | 2900 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 45,832 psi | 72% | 2759 fps | 98% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,840 psi | 58% | 1768 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 86% | 56,797 psi | 89% | 2828 fps | 99.9% |
| ReloadSwiss RS 52 | <<locked>> | 82% | 57,043 psi | 89% | 2897 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 88% | 57,232 psi | 90% | 2927 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 55,042 psi | 86% | 2881 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 94% | 57,725 psi | 90% | 2969 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 42,134 psi | 66% | 2782 fps | 98.1% |
| Rottweil R 902 | <<locked>> | 84% | 56,173 psi | 88% | 2762 fps | 100% |
| Rottweil R 903 | <<locked>> | 88% | 56,449 psi | 88% | 2815 fps | 100% |
| Rottweil R 904 | <<locked>> | 96% | 54,636 psi | 86% | 2822 fps | 97.8% |
| Rottweil R 905 | <<locked>> | 98% | 54,926 psi | 86% | 2881 fps | 98.9% |
| Rottweil R 907 | <<locked>> | 90% | 55,651 psi | 87% | 2808 fps | 99.4% |
| Shooters World Long Rifle | <<locked>> | 92% | 57,319 psi | 90% | 2828 fps | 100% |
| Shooters World Match Rifle | <<locked>> | 82% | 57,522 psi | 90% | 2792 fps | 100% |
| Shooters World Precision | <<locked>> | 84% | 54,447 psi | 85% | 2756 fps | 100% |
| Shooters World SW4350 | <<locked>> | 92% | 55,230 psi | 87% | 2825 fps | 99.7% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 54,418 psi | 85% | 2825 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 55,680 psi | 87% | 2799 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 82% | 56,492 psi | 89% | 2690 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 88% | 57,493 psi | 90% | 2694 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 92% | 57,261 psi | 90% | 2785 fps | 99.7% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 54,447 psi | 85% | 2877 fps | 98.9% |
| Somchem S335 | <<locked>> | 82% | 56,173 psi | 88% | 2690 fps | 100% |
| Somchem S355 | <<locked>> | 88% | 56,188 psi | 88% | 2808 fps | 100% |
| Somchem S361 | <<locked>> | 96% | 56,333 psi | 88% | 2815 fps | 97.3% |
| Somchem S365 | <<locked>> | 96% | 57,072 psi | 89% | 2894 fps | 100% |
| Somchem S385 | <<locked>> | 98% | 55,448 psi | 87% | 2854 fps | 99.4% |
| Vihtavuori N133 | <<locked>> | 82% | 57,058 psi | 89% | 2671 fps | 100% |
| Vihtavuori N135 | <<locked>> | 84% | 56,681 psi | 89% | 2720 fps | 100% |
| Vihtavuori N140 | <<locked>> | 84% | 57,087 psi | 89% | 2736 fps | 100% |
| Vihtavuori N150 | <<locked>> | 90% | 57,725 psi | 90% | 2782 fps | 100% |
| Vihtavuori N160 | <<locked>> | 92% | 56,173 psi | 88% | 2835 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 51,256 psi | 80% | 2776 fps | 98.7% |
| Vihtavuori N540 | <<locked>> | 84% | 55,158 psi | 86% | 2740 fps | 100% |
| Vihtavuori N550 | <<locked>> | 92% | 55,187 psi | 86% | 2841 fps | 100% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 55,637 psi | 87% | 2900 fps | 100% |
| Vihtavuori N560ᴾ | <<locked>> | 100% | 56,449 psi | 88% | 2969 fps | 97.8% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 55,898 psi | 88% | 2802 fps | 100% |
| Winchester 760 | <<locked>> | 90% | 54,114 psi | 85% | 2861 fps | 99.6% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 44,788 psi | 70% | 2887 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 82% | 55,796 psi | 87% | 2805 fps | 100% |
| Winchester Supreme 780ᴾ | <<locked>> | 100% | 55,796 psi | 87% | 2851 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 2495 | <<locked>> | 80% | 50,386 psi | 79% | 2641 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 48,544 psi | 76% | 2657 fps | 98.3% |
| Accurate 3100 | <<locked>> | 84% | 30,255 psi | 47% | 2372 fps | 95% |
| Accurate 4064 | <<locked>> | 80% | 47,805 psi | 75% | 2651 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 36,201 psi | 57% | 2523 fps | 98.6% |
| Accurate MAGPRO | <<locked>> | 96% | 47,761 psi | 75% | 2831 fps | 95.3% |
| ADI AR 2206H | <<locked>> | 80% | 53,519 psi | 84% | 2772 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 45,455 psi | 71% | 2631 fps | 99.9% |
| ADI AR 2209 | <<locked>> | 88% | 40,611 psi | 64% | 2625 fps | 95.6% |
| ADI AR 2213 | <<locked>> | 94% | 44,150 psi | 69% | 2723 fps | 95.2% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 50,285 psi | 79% | 2844 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 45,847 psi | 72% | 2654 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 49,008 psi | 77% | 2723 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 35,708 psi | 56% | 2539 fps | 98.8% |
| Alliant Reloder-17 | <<locked>> | 80% | 40,379 psi | 63% | 2661 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 40,263 psi | 63% | 2618 fps | 95.7% |
| Alliant Reloder-22 | <<locked>> | 90% | 37,666 psi | 59% | 2608 fps | 95% |
| Alliant Reloder-23 | <<locked>> | 80% | 25,860 psi | 41% | 2300 fps | 96.7% |
| Alliant Reloder-25 | <<locked>> | 90% | 31,285 psi | 49% | 2470 fps | 95.9% |
| Alliant Reloder-26 | 74.3 gr | 82% | 29,472 psi | 46% | 2464 fps | 96% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 53,403 psi | 84% | 2792 fps | 100% |
| Bofors RP15 | <<locked>> | 94% | 39,740 psi | 62% | 2651 fps | 95.5% |
| Bofors RP3 | <<locked>> | 80% | 45,890 psi | 72% | 2664 fps | 100% |
| Bofors RP5 | <<locked>> | 90% | 37,666 psi | 59% | 2608 fps | 95% |
| Bofors RP7 | <<locked>> | 80% | 40,596 psi | 64% | 2546 fps | 96.8% |
| Hodgdon H380 | <<locked>> | 80% | 46,499 psi | 73% | 2677 fps | 99.7% |
| Hodgdon H414 | <<locked>> | 80% | 38,479 psi | 60% | 2575 fps | 96.9% |
| Hodgdon H4350 | <<locked>> | 80% | 41,423 psi | 65% | 2595 fps | 96.3% |
| Hodgdon H4831 | <<locked>> | 94% | 47,268 psi | 74% | 2730 fps | 95.4% |
| Hodgdon H4831 SC | <<locked>> | 94% | 46,354 psi | 73% | 2713 fps | 95.2% |
| Hodgdon H4895 | <<locked>> | 80% | 54,143 psi | 85% | 2782 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 33,083 psi | 52% | 2431 fps | 99.2% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 50,850 psi | 80% | 2766 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 96% | 37,101 psi | 58% | 2657 fps | 95% |
| Hodgdon Superformance | 74.7 gr | 80% | 37,304 psi | 58% | 2582 fps | 96.1% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,035 psi | 42% | 1545 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 51,866 psi | 81% | 2733 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 47,805 psi | 75% | 2664 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 50,183 psi | 79% | 2697 fps | 99.1% |
| IMR 4350 | <<locked>> | 80% | 36,245 psi | 57% | 2470 fps | 95.5% |
| IMR 4451 Enduron | <<locked>> | 80% | 42,105 psi | 66% | 2575 fps | 97.6% |
| IMR 4831 | <<locked>> | 80% | 35,012 psi | 55% | 2480 fps | 98.4% |
| IMR 4895 | <<locked>> | 80% | 50,270 psi | 79% | 2749 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 92% | 46,180 psi | 72% | 2674 fps | 95.4% |
| IMR 7828 SSC | <<locked>> | 96% | 44,991 psi | 71% | 2753 fps | 95.6% |
| Lovex D073.6 | <<locked>> | 80% | 53,809 psi | 84% | 2746 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 52,591 psi | 82% | 2700 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 47,979 psi | 75% | 2657 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 39,537 psi | 62% | 2526 fps | 98.3% |
| Lovex S070 | <<locked>> | 80% | 37,681 psi | 59% | 2507 fps | 96.8% |
| Lovex S071 | <<locked>> | 90% | 31,401 psi | 49% | 2398 fps | 95.5% |
| Norma 201 | <<locked>> | 80% | 52,315 psi | 82% | 2717 fps | 100% |
| Norma 202 | <<locked>> | 80% | 52,953 psi | 83% | 2710 fps | 100% |
| Norma 203B | <<locked>> | 80% | 48,341 psi | 76% | 2707 fps | 100% |
| Norma 204 | <<locked>> | 84% | 40,973 psi | 64% | 2612 fps | 95.6% |
| Norma MRP | <<locked>> | 86% | 34,272 psi | 54% | 2556 fps | 95.2% |
| Norma URP | <<locked>> | 80% | 36,289 psi | 57% | 2523 fps | 98.6% |
| Ramshot Big Game | <<locked>> | 80% | 48,733 psi | 76% | 2733 fps | 100% |
| Ramshot Grand | <<locked>> | 96% | 44,657 psi | 70% | 2759 fps | 95.9% |
| Ramshot Hunter | <<locked>> | 80% | 35,157 psi | 55% | 2510 fps | 96.7% |
| Ramshot Magnum | <<locked>> | 94% | 36,782 psi | 58% | 2572 fps | 95.3% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,601 psi | 43% | 1585 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 46,528 psi | 73% | 2664 fps | 99% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 53,113 psi | 83% | 2838 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 42,989 psi | 67% | 2710 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 36,042 psi | 56% | 2543 fps | 98.4% |
| ReloadSwiss RS 70 | 71.8 gr | 80% | 35,172 psi | 55% | 2552 fps | 97.8% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 36,579 psi | 57% | 2648 fps | 96.1% |
| Rottweil R 902 | <<locked>> | 80% | 49,705 psi | 78% | 2671 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 43,294 psi | 68% | 2612 fps | 100% |
| Rottweil R 904 | <<locked>> | 90% | 44,991 psi | 71% | 2657 fps | 95.7% |
| Rottweil R 905 | <<locked>> | 88% | 39,131 psi | 61% | 2598 fps | 95.6% |
| Rottweil R 907 | <<locked>> | 80% | 40,596 psi | 64% | 2546 fps | 96.8% |
| Shooters World Long Rifle | <<locked>> | 80% | 39,537 psi | 62% | 2526 fps | 98.3% |
| Shooters World Match Rifle | <<locked>> | 80% | 53,809 psi | 84% | 2746 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 47,979 psi | 75% | 2657 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 37,681 psi | 59% | 2507 fps | 96.8% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 44,556 psi | 70% | 2667 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 52,054 psi | 82% | 2746 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 53,272 psi | 83% | 2648 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 44,947 psi | 70% | 2523 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 38,653 psi | 61% | 2470 fps | 96.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 38,754 psi | 61% | 2592 fps | 95.4% |
| Somchem S335 | <<locked>> | 80% | 52,924 psi | 83% | 2648 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 43,758 psi | 69% | 2615 fps | 100% |
| Somchem S361 | <<locked>> | 90% | 46,006 psi | 72% | 2651 fps | 95% |
| Somchem S365 | <<locked>> | 80% | 32,605 psi | 51% | 2477 fps | 99.8% |
| Somchem S385 | <<locked>> | 86% | 37,202 psi | 58% | 2526 fps | 95.8% |
| Vihtavuori N133 | <<locked>> | 80% | 53,882 psi | 84% | 2631 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 50,140 psi | 79% | 2631 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 50,343 psi | 79% | 2648 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 41,727 psi | 65% | 2543 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 37,666 psi | 59% | 2523 fps | 98.8% |
| Vihtavuori N165 | <<locked>> | 90% | 36,506 psi | 57% | 2503 fps | 95.1% |
| Vihtavuori N540 | <<locked>> | 80% | 48,530 psi | 76% | 2644 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 37,115 psi | 58% | 2523 fps | 98.5% |
| Vihtavuori N555 | <<locked>> | 80% | 28,311 psi | 44% | 2369 fps | 96.7% |
| Vihtavuori N560 | <<locked>> | 94% | 45,992 psi | 72% | 2792 fps | 95.5% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 36,840 psi | 58% | 2493 fps | 99.8% |
| Winchester 760 | <<locked>> | 80% | 38,479 psi | 60% | 2575 fps | 96.9% |
| Winchester StaBALL HD | <<locked>> | 82% | 24,265 psi | 38% | 2326 fps | 96.5% |
| Winchester StaBALL Match | <<locked>> | 80% | 52,112 psi | 82% | 2753 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 90% | 39,204 psi | 61% | 2566 fps | 95.3% |
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 103 powders for 8.5 mm Messner Mag. loaded with the .338 | 225gr | Barnes TTSX BT. Alliant Reloder-26 delivers the highest muzzle velocity at 3,025 fps; across all powders the maximum-charge window runs from 1,729 fps to 3,025 fps. Accurate 3100 gives the best case fill at 100 %, and 103 of the 103 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 1:12.5 twist; slower twists will usually not stabilise this weight. Accurate 3100, Accurate MAGPRO, ADI AR 2213 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-26, Hodgdon Superformance rank at the top here: for 8.5 mm Messner Mag. with the .338 | 225gr | Barnes TTSX BT 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.