Load Specifications
Load data in caliber 8.5 mm Messner Mag. with .338 | 300gr | Nosler Custom Competition bullet and 77 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Winchester StaBALL HD, Vihtavuori N560 and Accurate MAGPRO.
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 3100 | <<locked>> | 94% | 55,593 psi | 87% | 2461 fps | 100% |
| Accurate 4350 | <<locked>> | 86% | 57,159 psi | 90% | 2477 fps | 100% |
| Accurate MAGPRO | <<locked>> | 92% | 53,882 psi | 84% | 2556 fps | 99.3% |
| ADI AR 2209 | <<locked>> | 92% | 57,580 psi | 90% | 2539 fps | 100% |
| ADI AR 2213 | <<locked>> | 94% | 55,332 psi | 87% | 2552 fps | 99.8% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 49,414 psi | 77% | 2470 fps | 99.5% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 44,164 psi | 69% | 2448 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 86% | 54,505 psi | 85% | 2480 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 82% | 55,332 psi | 87% | 2490 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 92% | 57,043 psi | 89% | 2530 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 94% | 55,332 psi | 87% | 2549 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 96% | 56,594 psi | 89% | 2507 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 55,738 psi | 87% | 2569 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 92% | 56,927 psi | 89% | 2595 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 45,353 psi | 71% | 2487 fps | 96.2% |
| Baschieri & Pellagri 109 | <<locked>> | 96% | 56,826 psi | 89% | 2520 fps | 98.3% |
| Bofors RP15 | <<locked>> | 96% | 54,288 psi | 85% | 2533 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 51,648 psi | 81% | 2533 fps | 99.8% |
| Bofors RP5 | <<locked>> | 94% | 55,332 psi | 87% | 2549 fps | 100% |
| Bofors RP7 | <<locked>> | 84% | 55,782 psi | 87% | 2431 fps | 100% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 54,520 psi | 85% | 2543 fps | 100% |
| Hodgdon H414 | <<locked>> | 84% | 54,955 psi | 86% | 2484 fps | 100% |
| Hodgdon H4350 | <<locked>> | 84% | 57,696 psi | 90% | 2490 fps | 100% |
| Hodgdon H4831 | <<locked>> | 92% | 55,201 psi | 87% | 2493 fps | 99.5% |
| Hodgdon H4831 SC | <<locked>> | 92% | 54,288 psi | 85% | 2484 fps | 99.4% |
| Hodgdon Hybrid 100V | <<locked>> | 88% | 54,694 psi | 86% | 2411 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 54,694 psi | 86% | 2648 fps | 100% |
| Hodgdon Superformance | <<locked>> | 84% | 55,245 psi | 87% | 2523 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,318 psi | 58% | 1496 fps | 100% |
| IMR 4350 | <<locked>> | 88% | 57,261 psi | 90% | 2470 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 84% | 57,261 psi | 90% | 2451 fps | 100% |
| IMR 4831 | <<locked>> | 88% | 57,261 psi | 90% | 2467 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 92% | 56,231 psi | 88% | 2477 fps | 99.6% |
| IMR 7828 SSC | <<locked>> | 96% | 56,898 psi | 89% | 2582 fps | 99.9% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 39,798 psi | 62% | 2369 fps | 98.2% |
| Lovex S065 | <<locked>> | 84% | 54,476 psi | 85% | 2405 fps | 100% |
| Lovex S070 | <<locked>> | 86% | 55,956 psi | 88% | 2448 fps | 100% |
| Lovex S071ᴾ | <<locked>> | 100% | 56,521 psi | 89% | 2470 fps | 100% |
| Norma 204 | <<locked>> | 86% | 54,737 psi | 86% | 2480 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 39,827 psi | 62% | 2392 fps | 99.7% |
| Norma MRP | <<locked>> | 92% | 55,201 psi | 87% | 2566 fps | 100% |
| Norma URP | <<locked>> | 86% | 55,405 psi | 87% | 2464 fps | 100% |
| Ramshot Grand | <<locked>> | 94% | 53,751 psi | 84% | 2552 fps | 99.9% |
| Ramshot Hunter | <<locked>> | 86% | 54,288 psi | 85% | 2477 fps | 100% |
| Ramshot Magnum | <<locked>> | 98% | 55,811 psi | 87% | 2543 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,130 psi | 60% | 1532 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 86% | 56,985 psi | 89% | 2503 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 86% | 55,158 psi | 86% | 2530 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 55,071 psi | 86% | 2644 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 49,879 psi | 78% | 2556 fps | 99% |
| Rottweil R 903 | <<locked>> | 82% | 57,188 psi | 90% | 2421 fps | 100% |
| Rottweil R 904 | <<locked>> | 90% | 55,288 psi | 87% | 2464 fps | 99.8% |
| Rottweil R 905 | <<locked>> | 92% | 56,768 psi | 89% | 2523 fps | 100% |
| Rottweil R 907 | <<locked>> | 84% | 55,782 psi | 87% | 2431 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 84% | 54,476 psi | 85% | 2405 fps | 100% |
| Shooters World SW4350 | <<locked>> | 86% | 55,956 psi | 88% | 2448 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 82% | 56,826 psi | 89% | 2297 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 56,956 psi | 89% | 2408 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 92% | 56,333 psi | 88% | 2520 fps | 100% |
| Somchem S355 | <<locked>> | 82% | 56,840 psi | 89% | 2415 fps | 100% |
| Somchem S361 | <<locked>> | 90% | 56,695 psi | 89% | 2464 fps | 99.5% |
| Somchem S365 | <<locked>> | 88% | 55,883 psi | 88% | 2464 fps | 100% |
| Somchem S385 | <<locked>> | 92% | 57,246 psi | 90% | 2497 fps | 100% |
| Vihtavuori N150 | <<locked>> | 82% | 54,462 psi | 85% | 2349 fps | 100% |
| Vihtavuori N160 | <<locked>> | 86% | 57,290 psi | 90% | 2454 fps | 100% |
| Vihtavuori N165 | <<locked>> | 96% | 56,637 psi | 89% | 2480 fps | 100% |
| Vihtavuori N170ᴾ | <<locked>> | 100% | 54,853 psi | 86% | 2493 fps | 96.4% |
| Vihtavuori N550 | <<locked>> | 86% | 56,304 psi | 88% | 2464 fps | 100% |
| Vihtavuori N555 | <<locked>> | 92% | 55,448 psi | 87% | 2487 fps | 100% |
| Vihtavuori N560 | <<locked>> | 92% | 55,013 psi | 86% | 2569 fps | 99.7% |
| Vihtavuori N565 | <<locked>> | 98% | 54,737 psi | 86% | 2552 fps | 99.7% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 51,227 psi | 80% | 2556 fps | 98.8% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 48,341 psi | 76% | 2549 fps | 96.7% |
| Winchester 6.5 StaBALL | <<locked>> | 86% | 56,521 psi | 89% | 2418 fps | 100% |
| Winchester 760 | <<locked>> | 84% | 55,143 psi | 86% | 2484 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 96% | 54,114 psi | 85% | 2589 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 94% | 57,029 psi | 89% | 2497 fps | 100% |
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 3100 | <<locked>> | 80% | 34,954 psi | 55% | 2146 fps | 99.3% |
| Accurate 4350 | <<locked>> | 80% | 46,731 psi | 73% | 2343 fps | 100% |
| Accurate MAGPRO | 68.8 gr | 80% | 35,549 psi | 56% | 2241 fps | 95.2% |
| ADI AR 2209 | <<locked>> | 80% | 39,030 psi | 61% | 2254 fps | 98.4% |
| ADI AR 2213 | <<locked>> | 80% | 34,722 psi | 54% | 2198 fps | 95.9% |
| ADI AR 2217 | <<locked>> | 88% | 33,489 psi | 52% | 2172 fps | 95.7% |
| ADI AR 2225 | <<locked>> | 84% | 26,600 psi | 42% | 2047 fps | 95.7% |
| Alliant Reloder-16 | <<locked>> | 80% | 44,773 psi | 70% | 2349 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 80% | 51,634 psi | 81% | 2444 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 38,957 psi | 61% | 2251 fps | 98.4% |
| Alliant Reloder-22 | <<locked>> | 80% | 34,766 psi | 54% | 2208 fps | 97.5% |
| Alliant Reloder-23 | <<locked>> | 80% | 33,562 psi | 53% | 2169 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 29,240 psi | 46% | 2110 fps | 98.7% |
| Alliant Reloder-26 | <<locked>> | 80% | 36,651 psi | 57% | 2300 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 98% | 42,177 psi | 66% | 2428 fps | 95.2% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 44,614 psi | 70% | 2329 fps | 95.8% |
| Bofors RP15 | <<locked>> | 80% | 32,445 psi | 51% | 2156 fps | 96.6% |
| Bofors RP30 | <<locked>> | 84% | 30,443 psi | 48% | 2142 fps | 95.1% |
| Bofors RP5 | <<locked>> | 80% | 34,766 psi | 54% | 2208 fps | 97.5% |
| Bofors RP7 | <<locked>> | 80% | 49,269 psi | 77% | 2343 fps | 100% |
| Hodgdon H1000 | <<locked>> | 84% | 31,952 psi | 50% | 2139 fps | 95.7% |
| Hodgdon H414 | <<locked>> | 80% | 48,298 psi | 76% | 2392 fps | 100% |
| Hodgdon H4350 | <<locked>> | 80% | 50,778 psi | 80% | 2398 fps | 99.9% |
| Hodgdon H4831 | <<locked>> | 80% | 37,115 psi | 58% | 2201 fps | 96.1% |
| Hodgdon H4831 SC | <<locked>> | 80% | 36,376 psi | 57% | 2188 fps | 95.9% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 42,308 psi | 66% | 2244 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 80% | 28,572 psi | 45% | 2126 fps | 95.4% |
| Hodgdon Superformance | <<locked>> | 80% | 47,834 psi | 75% | 2421 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,920 psi | 44% | 1332 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 44,788 psi | 70% | 2293 fps | 99.7% |
| IMR 4451 Enduron | <<locked>> | 80% | 50,720 psi | 79% | 2365 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 44,483 psi | 70% | 2297 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 38,885 psi | 61% | 2201 fps | 96.8% |
| IMR 7828 SSC | <<locked>> | 80% | 33,475 psi | 52% | 2182 fps | 95.6% |
| IMR 8133 Enduron | <<locked>> | 94% | 32,793 psi | 51% | 2221 fps | 95.8% |
| Lovex S065 | <<locked>> | 80% | 48,196 psi | 76% | 2320 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 46,528 psi | 73% | 2316 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 30,226 psi | 47% | 2047 fps | 98.3% |
| Norma 204 | <<locked>> | 80% | 44,657 psi | 70% | 2329 fps | 99.2% |
| Norma 217 | <<locked>> | 88% | 27,035 psi | 42% | 2093 fps | 95.5% |
| Norma MRP | <<locked>> | 80% | 36,434 psi | 57% | 2267 fps | 99.1% |
| Norma URP | <<locked>> | 80% | 45,774 psi | 72% | 2333 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 32,909 psi | 52% | 2182 fps | 95.8% |
| Ramshot Hunter | <<locked>> | 80% | 44,512 psi | 70% | 2339 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 29,211 psi | 46% | 2083 fps | 96.2% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,529 psi | 45% | 1365 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 46,572 psi | 73% | 2365 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 44,802 psi | 70% | 2388 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 27,427 psi | 43% | 2103 fps | 96.1% |
| ReloadSwiss RS 80 | <<locked>> | 90% | 34,722 psi | 54% | 2277 fps | 95% |
| Rottweil R 903 | <<locked>> | 80% | 53,722 psi | 84% | 2379 fps | 100% |
| Rottweil R 904 | <<locked>> | 80% | 40,335 psi | 63% | 2231 fps | 97.7% |
| Rottweil R 905 | <<locked>> | 80% | 38,305 psi | 60% | 2238 fps | 98.4% |
| Rottweil R 907 | <<locked>> | 80% | 49,269 psi | 77% | 2343 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 80% | 48,196 psi | 76% | 2320 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 46,528 psi | 73% | 2316 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 53,606 psi | 84% | 2260 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 47,195 psi | 74% | 2280 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 38,000 psi | 60% | 2234 fps | 98.3% |
| Somchem S355 | <<locked>> | 80% | 53,447 psi | 84% | 2375 fps | 100% |
| Somchem S361 | <<locked>> | 80% | 40,959 psi | 64% | 2228 fps | 97.1% |
| Somchem S365 | <<locked>> | 80% | 42,946 psi | 67% | 2297 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 38,841 psi | 61% | 2221 fps | 99% |
| Vihtavuori N150 | <<locked>> | 80% | 51,126 psi | 80% | 2306 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 47,181 psi | 74% | 2323 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 33,692 psi | 53% | 2116 fps | 97.6% |
| Vihtavuori N170 | <<locked>> | 98% | 51,532 psi | 81% | 2448 fps | 95.7% |
| Vihtavuori N550 | <<locked>> | 80% | 46,441 psi | 73% | 2329 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 37,797 psi | 59% | 2231 fps | 100% |
| Vihtavuori N560 | 67.6 gr | 80% | 36,637 psi | 57% | 2260 fps | 96.3% |
| Vihtavuori N565 | <<locked>> | 84% | 34,243 psi | 54% | 2205 fps | 95.7% |
| Vihtavuori N568 | <<locked>> | 90% | 36,332 psi | 57% | 2293 fps | 95% |
| Vihtavuori N570 | <<locked>> | 98% | 45,310 psi | 71% | 2497 fps | 95.8% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 46,209 psi | 72% | 2290 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 48,457 psi | 76% | 2395 fps | 100% |
| Winchester StaBALL HD | 66.8 gr | 80% | 29,762 psi | 47% | 2205 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 35,462 psi | 56% | 2159 fps | 97.5% |
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 77 powders for 8.5 mm Messner Mag. loaded with the .338 | 300gr | Nosler Custom Competition. Hodgdon Retumbo delivers the highest muzzle velocity at 2,648 fps; across all powders the maximum-charge window runs from 1,496 fps to 2,648 fps. ADI AR 2217 gives the best case fill at 100 %, and 77 of the 77 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 300.0 gr projectile in 0.338" calls for a 1:12.0 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2225, 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. Winchester StaBALL HD, Vihtavuori N560, Accurate MAGPRO rank at the top here: for 8.5 mm Messner Mag. with the .338 | 300gr | Nosler Custom Competition 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.