Load Specifications
Load data in caliber 8 x 58 R with .318 | 150gr | Fox Classic Hunter bullet and 4 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.
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 |
|---|---|---|---|---|---|---|
| Hodgdon TrailBoss | <<locked>> | 96% | 28,253 psi | 89% | 1463 fps | 100% |
| IMR 4198 | <<locked>> | 82% | 28,689 psi | 90% | 2139 fps | 96% |
| Norma 200 | <<locked>> | 82% | 28,703 psi | 90% | 2195 fps | 96.2% |
| ReloadSwiss RS 14 | <<locked>> | 98% | 28,834 psi | 90% | 1519 fps | 100% |
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 |
|---|---|---|---|---|---|---|
| Hodgdon TrailBoss | 9.2 gr | 80% | 21,959 psi | 69% | 1335 fps | 100% |
| IMR 4198 | <<locked>> | 80% | 27,079 psi | 85% | 2096 fps | 95.2% |
| Norma 200 | <<locked>> | 80% | 26,760 psi | 84% | 2146 fps | 95.4% |
| ReloadSwiss RS 14 | 9.4 gr | 80% | 21,654 psi | 68% | 1368 fps | 100% |
Recommended = one of the top powders for this cartridge and bullet combination.
This overview compares 4 powders for 8 x 58 R loaded with the .318 | 150gr | Fox Classic Hunter. Norma 200 delivers the highest muzzle velocity at 2,195 fps; across all powders the maximum-charge window runs from 1,463 fps to 2,195 fps. ReloadSwiss RS 14 gives the best case fill at 98 %, and 4 of the 4 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (220 MPa), the top charges use 89–90 %, leaving at least 10 % headroom. The 150.0 gr projectile in 0.318" calls for a 1:13.0 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 | 150gr | Fox Classic Hunter 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.