Load Specifications
Load data in caliber 8 x 58 R with .318 | 200gr | Woodleigh RN SN bullet and 6 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ReloadSwiss RS 14 and Hodgdon TrailBoss.
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.
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Max Load - Barrel Length: 23.62"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2495 | <<locked>> | 88% | 28,485 psi | 89% | 1969 fps | 98.4% |
| Accurate 4064 | <<locked>> | 90% | 28,689 psi | 90% | 1982 fps | 95.8% |
| Hodgdon TrailBoss | <<locked>> | 90% | 28,224 psi | 88% | 1253 fps | 100% |
| IMR 3031 | <<locked>> | 82% | 27,441 psi | 86% | 1942 fps | 96.5% |
| ReloadSwiss RS 14 | <<locked>> | 90% | 28,152 psi | 88% | 1286 fps | 100% |
| Vihtavuori N135 | <<locked>> | 86% | 28,471 psi | 89% | 1942 fps | 98.1% |
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 2495 | <<locked>> | 80% | 22,075 psi | 69% | 1811 fps | 95.7% |
| Accurate 4064 | <<locked>> | 88% | 26,919 psi | 84% | 1942 fps | 95% |
| Hodgdon TrailBoss | 9.5 gr | 80% | 24,047 psi | 75% | 1181 fps | 100% |
| IMR 3031 | <<locked>> | 80% | 25,788 psi | 81% | 1900 fps | 95.7% |
| ReloadSwiss RS 14 | 9.7 gr | 80% | 24,047 psi | 75% | 1211 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 23,757 psi | 74% | 1827 fps | 96.1% |
Recommended = one of the top powders for this cartridge and bullet combination.
This overview compares 6 powders for 8 x 58 R loaded with the .318 | 200gr | Woodleigh RN SN. Accurate 4064 delivers the highest muzzle velocity at 1,982 fps; across all powders the maximum-charge window runs from 1,253 fps to 1,982 fps. Accurate 4064 gives the best case fill at 90 %, and 6 of the 6 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (220 MPa), the top charges use 86–90 %, leaving at least 10 % headroom. The 200.0 gr projectile in 0.318" calls for a 1:16.0 twist; slower twists will usually not stabilise this weight. ReloadSwiss RS 14, Hodgdon TrailBoss rank at the top here: for 8 x 58 R with the .318 | 200gr | 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.