Load Specifications
Load data in caliber 8 x 56 R M 89 Port. Krop. with .323 | 250gr | Woodleigh RN SN bullet and 57 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-26, Alliant Reloder-16 and Somchem S365.
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: 23.62"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2700 | <<locked>> | 82% | 44,527 psi | 90% | 2142 fps | 96.4% |
| Accurate 3100ᴾ | <<locked>> | 100% | 41,887 psi | 85% | 2205 fps | 97.7% |
| Accurate 4064 | <<locked>> | 82% | 43,120 psi | 87% | 2152 fps | 100% |
| Accurate 4350 | <<locked>> | 92% | 44,541 psi | 90% | 2254 fps | 99.4% |
| ADI AR 2208 | <<locked>> | 84% | 44,396 psi | 90% | 2175 fps | 99.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 44,251 psi | 90% | 2195 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 44,411 psi | 90% | 2205 fps | 99.7% |
| Alliant Reloder-16 | <<locked>> | 92% | 43,845 psi | 89% | 2264 fps | 99.6% |
| Alliant Reloder-17 | <<locked>> | 88% | 43,758 psi | 89% | 2283 fps | 100% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 39,914 psi | 81% | 2231 fps | 99.8% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 35,360 psi | 72% | 2149 fps | 96.2% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 44,338 psi | 90% | 2369 fps | 99.4% |
| Bofors RP3 | <<locked>> | 84% | 44,135 psi | 90% | 2201 fps | 100% |
| Bofors RP7 | <<locked>> | 88% | 44,541 psi | 90% | 2178 fps | 96.7% |
| Hodgdon H380 | <<locked>> | 82% | 42,119 psi | 85% | 2165 fps | 98.7% |
| Hodgdon H414 | <<locked>> | 90% | 44,280 psi | 90% | 2254 fps | 97.4% |
| Hodgdon Hybrid 100V | <<locked>> | 94% | 43,163 psi | 88% | 2208 fps | 99.9% |
| Hodgdon Superformance | <<locked>> | 90% | 44,005 psi | 89% | 2274 fps | 96.8% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,795 psi | 73% | 1381 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 43,700 psi | 89% | 2156 fps | 99.6% |
| IMR 4350 | <<locked>> | 90% | 42,018 psi | 85% | 2162 fps | 96.1% |
| IMR 4451 Enduron | <<locked>> | 86% | 43,598 psi | 88% | 2162 fps | 96.9% |
| IMR 4831 | <<locked>> | 92% | 42,656 psi | 87% | 2211 fps | 99.2% |
| Lovex S062 | <<locked>> | 82% | 43,685 psi | 89% | 2156 fps | 100% |
| Lovex S065 | <<locked>> | 88% | 43,163 psi | 88% | 2162 fps | 98.2% |
| Lovex S070 | <<locked>> | 90% | 43,482 psi | 88% | 2188 fps | 97.3% |
| Lovex S071ᴾ | <<locked>> | 100% | 34,853 psi | 71% | 2087 fps | 95.8% |
| Norma 203B | <<locked>> | 82% | 43,758 psi | 89% | 2192 fps | 99.8% |
| Norma MRPᴾ | <<locked>> | 100% | 44,599 psi | 90% | 2333 fps | 97.3% |
| Norma URP | <<locked>> | 92% | 44,367 psi | 90% | 2251 fps | 99.4% |
| Ramshot Big Game | <<locked>> | 82% | 43,555 psi | 88% | 2215 fps | 99.8% |
| Ramshot Hunter | <<locked>> | 92% | 43,163 psi | 88% | 2244 fps | 97.9% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,187 psi | 73% | 1414 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 42,438 psi | 86% | 2152 fps | 97.4% |
| ReloadSwiss RS 60 | <<locked>> | 86% | 43,642 psi | 89% | 2283 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 44,266 psi | 90% | 2277 fps | 99.2% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 43,874 psi | 89% | 2290 fps | 98.9% |
| Rottweil R 903 | <<locked>> | 86% | 44,005 psi | 89% | 2195 fps | 100% |
| Rottweil R 905 | <<locked>> | 98% | 44,266 psi | 90% | 2257 fps | 95.8% |
| Rottweil R 907 | <<locked>> | 88% | 44,541 psi | 90% | 2178 fps | 96.7% |
| Shooters World Long Rifle | <<locked>> | 88% | 43,163 psi | 88% | 2162 fps | 98.2% |
| Shooters World Precision | <<locked>> | 82% | 43,685 psi | 89% | 2156 fps | 100% |
| Shooters World SW4350 | <<locked>> | 90% | 43,482 psi | 88% | 2188 fps | 97.3% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 42,409 psi | 86% | 2201 fps | 99.7% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 43,961 psi | 89% | 2087 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 42,627 psi | 86% | 2119 fps | 96.8% |
| Somchem S355 | <<locked>> | 84% | 42,090 psi | 85% | 2156 fps | 99.8% |
| Somchem S365 | <<locked>> | 94% | 42,337 psi | 86% | 2254 fps | 100% |
| Somchem S385 | <<locked>> | 96% | 42,134 psi | 85% | 2201 fps | 96.2% |
| Vihtavuori N150 | <<locked>> | 86% | 42,699 psi | 87% | 2139 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 43,584 psi | 88% | 2205 fps | 99.2% |
| Vihtavuori N540 | <<locked>> | 82% | 44,237 psi | 90% | 2152 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 42,714 psi | 87% | 2208 fps | 98.9% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 43,874 psi | 89% | 2290 fps | 99.7% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 43,192 psi | 88% | 2185 fps | 100% |
| Winchester 760 | <<locked>> | 90% | 44,527 psi | 90% | 2257 fps | 97.5% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 35,694 psi | 72% | 2247 fps | 99.9% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 23.62"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2700 | <<locked>> | 80% | 41,756 psi | 85% | 2100 fps | 95.7% |
| Accurate 3100 | <<locked>> | 94% | 34,156 psi | 69% | 2073 fps | 95.6% |
| Accurate 4064 | <<locked>> | 80% | 40,321 psi | 82% | 2113 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 29,747 psi | 60% | 1985 fps | 95.9% |
| ADI AR 2208 | <<locked>> | 80% | 39,175 psi | 79% | 2090 fps | 98.9% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 39,044 psi | 79% | 2110 fps | 99.7% |
| Alliant Reloder-15 | <<locked>> | 80% | 41,843 psi | 85% | 2162 fps | 99.4% |
| Alliant Reloder-16 | 41.3 gr | 80% | 30,211 psi | 61% | 1995 fps | 96% |
| Alliant Reloder-17 | <<locked>> | 80% | 33,475 psi | 68% | 2096 fps | 98.8% |
| Alliant Reloder-23 | <<locked>> | 86% | 26,165 psi | 53% | 1926 fps | 95.7% |
| Alliant Reloder-25 | <<locked>> | 98% | 33,243 psi | 67% | 2100 fps | 95.2% |
| Alliant Reloder-26 | 51.3 gr | 90% | 31,546 psi | 64% | 2113 fps | 95.7% |
| Bofors RP3 | <<locked>> | 80% | 38,595 psi | 78% | 2113 fps | 99.8% |
| Bofors RP7 | <<locked>> | 84% | 39,595 psi | 80% | 2093 fps | 95.4% |
| Hodgdon H380 | <<locked>> | 80% | 39,421 psi | 80% | 2119 fps | 98.2% |
| Hodgdon H414 | <<locked>> | 84% | 36,347 psi | 74% | 2113 fps | 95.2% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 27,833 psi | 56% | 1916 fps | 96.9% |
| Hodgdon Superformance | <<locked>> | 86% | 38,261 psi | 78% | 2172 fps | 95% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,643 psi | 54% | 1230 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 41,162 psi | 83% | 2116 fps | 99.4% |
| IMR 4350 | <<locked>> | 88% | 39,421 psi | 80% | 2116 fps | 95.3% |
| IMR 4451 Enduron | <<locked>> | 82% | 38,609 psi | 78% | 2077 fps | 95.6% |
| IMR 4831 | <<locked>> | 80% | 28,993 psi | 59% | 1955 fps | 95.6% |
| Lovex S062 | <<locked>> | 80% | 41,162 psi | 83% | 2116 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 33,765 psi | 68% | 1995 fps | 95.7% |
| Lovex S070 | <<locked>> | 84% | 36,274 psi | 74% | 2060 fps | 95.3% |
| Lovex S071 | <<locked>> | 98% | 32,721 psi | 66% | 2044 fps | 95% |
| Norma 203B | <<locked>> | 80% | 41,249 psi | 84% | 2156 fps | 99.6% |
| Norma MRP | <<locked>> | 96% | 39,102 psi | 79% | 2234 fps | 95.7% |
| Norma URP | <<locked>> | 80% | 30,211 psi | 61% | 1988 fps | 95.8% |
| Ramshot Big Game | <<locked>> | 80% | 40,538 psi | 82% | 2165 fps | 99.5% |
| Ramshot Hunter | <<locked>> | 86% | 35,607 psi | 72% | 2106 fps | 95.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,093 psi | 55% | 1263 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 39,798 psi | 81% | 2106 fps | 96.8% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 35,636 psi | 72% | 2146 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 29,472 psi | 60% | 1998 fps | 95.2% |
| ReloadSwiss RS 70 | <<locked>> | 82% | 31,676 psi | 64% | 2047 fps | 95.1% |
| Rottweil R 903 | <<locked>> | 80% | 36,405 psi | 74% | 2070 fps | 99.4% |
| Rottweil R 905 | <<locked>> | 96% | 41,655 psi | 84% | 2215 fps | 95.1% |
| Rottweil R 907 | <<locked>> | 84% | 39,595 psi | 80% | 2093 fps | 95.4% |
| Shooters World Long Rifle | <<locked>> | 80% | 33,765 psi | 68% | 1995 fps | 95.7% |
| Shooters World Precision | <<locked>> | 80% | 41,162 psi | 83% | 2116 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 36,274 psi | 74% | 2060 fps | 95.3% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 37,144 psi | 75% | 2113 fps | 99% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 38,624 psi | 78% | 2011 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 37,521 psi | 76% | 2034 fps | 95.4% |
| Somchem S355 | <<locked>> | 80% | 37,086 psi | 75% | 2070 fps | 99.3% |
| Somchem S365 | 42.2 gr | 80% | 26,992 psi | 55% | 1949 fps | 98% |
| Somchem S385 | <<locked>> | 94% | 39,421 psi | 80% | 2156 fps | 95.4% |
| Vihtavuori N150 | <<locked>> | 80% | 35,331 psi | 72% | 2021 fps | 99.7% |
| Vihtavuori N160 | <<locked>> | 80% | 31,575 psi | 64% | 1988 fps | 96.3% |
| Vihtavuori N540 | <<locked>> | 80% | 41,466 psi | 84% | 2113 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 30,951 psi | 63% | 1991 fps | 95.8% |
| Vihtavuori N555 | <<locked>> | 86% | 27,963 psi | 57% | 1985 fps | 95.8% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 31,183 psi | 63% | 1969 fps | 98.2% |
| Winchester 760 | <<locked>> | 84% | 36,593 psi | 74% | 2119 fps | 95.2% |
| Winchester StaBALL HD | <<locked>> | 90% | 26,063 psi | 53% | 1991 fps | 96.2% |
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 57 powders for 8 x 56 R M 89 Port. Krop. loaded with the .323 | 250gr | Woodleigh RN SN. Alliant Reloder-26 delivers the highest muzzle velocity at 2,369 fps; across all powders the maximum-charge window runs from 1,381 fps to 2,369 fps. Accurate 3100 gives the best case fill at 100 %, and 57 of the 57 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (340 MPa), the top charges use 71–90 %, leaving at least 10 % headroom. The 250.0 gr projectile in 0.323" calls for a 1:14.5 twist; slower twists will usually not stabilise this weight. Accurate 3100, 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. Alliant Reloder-26, Alliant Reloder-16, Somchem S365 rank at the top here: for 8 x 56 R M 89 Port. Krop. with the .323 | 250gr | Woodleigh RN SN 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.