Load Specifications
Load data in caliber 6.5 x 58 mm Mauser Port. with .263 | 139gr | Prvi Partizan FMJ BT bullet and 52 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-26, Norma MRP and Winchester StaBALL HD.
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 3100 | <<locked>> | 96% | 44,599 psi | 87% | 2572 fps | 98.4% |
| Accurate 4350 | <<locked>> | 86% | 43,714 psi | 85% | 2569 fps | 99.4% |
| ADI AR 2209 | <<locked>> | 92% | 45,179 psi | 88% | 2608 fps | 95.9% |
| Alliant Power Pro Varmint | <<locked>> | 92% | 45,063 psi | 88% | 2605 fps | 96% |
| Alliant Reloder-16 | <<locked>> | 88% | 45,179 psi | 88% | 2635 fps | 99.8% |
| Alliant Reloder-17 | <<locked>> | 84% | 45,179 psi | 88% | 2648 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 92% | 44,541 psi | 87% | 2598 fps | 95.9% |
| Alliant Reloder-22 | <<locked>> | 96% | 44,556 psi | 87% | 2644 fps | 96.1% |
| Alliant Reloder-23 | <<locked>> | 98% | 45,223 psi | 88% | 2651 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 42,032 psi | 82% | 2621 fps | 98.6% |
| Alliant Reloder-26 | <<locked>> | 94% | 44,324 psi | 86% | 2707 fps | 99.5% |
| Bofors RP5 | <<locked>> | 96% | 44,556 psi | 87% | 2644 fps | 96.1% |
| Bofors RP7 | <<locked>> | 84% | 45,266 psi | 88% | 2530 fps | 97.1% |
| Hodgdon H414 | <<locked>> | 86% | 45,948 psi | 89% | 2618 fps | 97.9% |
| Hodgdon H4350 | <<locked>> | 84% | 46,282 psi | 90% | 2582 fps | 96.7% |
| Hodgdon Hybrid 100V | <<locked>> | 90% | 45,005 psi | 87% | 2569 fps | 100% |
| Hodgdon Superformance | <<locked>> | 86% | 45,179 psi | 88% | 2638 fps | 97.4% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,216 psi | 70% | 1660 fps | 100% |
| IMR 4350 | <<locked>> | 88% | 46,050 psi | 89% | 2566 fps | 97.3% |
| IMR 4451 Enduron | <<locked>> | 82% | 43,961 psi | 85% | 2507 fps | 97.2% |
| IMR 4831 | <<locked>> | 88% | 44,614 psi | 87% | 2572 fps | 99.5% |
| Lovex S065 | <<locked>> | 84% | 44,092 psi | 86% | 2513 fps | 98.5% |
| Lovex S070 | <<locked>> | 86% | 44,889 psi | 87% | 2546 fps | 97.8% |
| Lovex S071ᴾ | <<locked>> | 100% | 42,772 psi | 83% | 2543 fps | 98% |
| Norma 204 | <<locked>> | 88% | 45,890 psi | 89% | 2602 fps | 96% |
| Norma MRP | <<locked>> | 94% | 43,830 psi | 85% | 2661 fps | 97.4% |
| Norma URP | <<locked>> | 88% | 46,137 psi | 90% | 2615 fps | 99.6% |
| Ramshot Hunter | <<locked>> | 88% | 45,034 psi | 87% | 2612 fps | 98.4% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 44,295 psi | 86% | 2621 fps | 96.6% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,825 psi | 72% | 1696 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 82% | 44,846 psi | 87% | 2644 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 46,543 psi | 90% | 2644 fps | 99.5% |
| ReloadSwiss RS 70 | <<locked>> | 88% | 45,484 psi | 88% | 2667 fps | 99.4% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 40,770 psi | 79% | 2631 fps | 96.4% |
| Rottweil R 903 | <<locked>> | 82% | 45,527 psi | 88% | 2552 fps | 100% |
| Rottweil R 905 | <<locked>> | 94% | 46,441 psi | 90% | 2635 fps | 96.6% |
| Rottweil R 907 | <<locked>> | 84% | 45,266 psi | 88% | 2530 fps | 97.1% |
| Shooters World Long Rifle | <<locked>> | 84% | 44,092 psi | 86% | 2513 fps | 98.5% |
| Shooters World SW4350 | <<locked>> | 86% | 44,889 psi | 87% | 2546 fps | 97.8% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 46,137 psi | 90% | 2510 fps | 97.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 46,021 psi | 89% | 2628 fps | 96.5% |
| Somchem S355 | <<locked>> | 82% | 45,658 psi | 89% | 2546 fps | 100% |
| Somchem S365 | <<locked>> | 90% | 44,918 psi | 87% | 2621 fps | 100% |
| Somchem S385 | <<locked>> | 92% | 44,266 psi | 86% | 2566 fps | 96.9% |
| Vihtavuori N150 | <<locked>> | 84% | 46,572 psi | 90% | 2526 fps | 100% |
| Vihtavuori N160 | <<locked>> | 86% | 44,962 psi | 87% | 2559 fps | 99.4% |
| Vihtavuori N165 | <<locked>> | 98% | 46,427 psi | 90% | 2592 fps | 97% |
| Vihtavuori N550 | <<locked>> | 86% | 44,251 psi | 86% | 2562 fps | 99.2% |
| Vihtavuori N555 | <<locked>> | 94% | 44,396 psi | 86% | 2621 fps | 99.7% |
| Winchester 6.5 StaBALL | <<locked>> | 86% | 44,353 psi | 86% | 2536 fps | 100% |
| Winchester 760 | <<locked>> | 86% | 46,238 psi | 90% | 2625 fps | 98% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 43,265 psi | 84% | 2746 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 |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 88% | 34,214 psi | 66% | 2369 fps | 95.5% |
| Accurate 4350 | <<locked>> | 80% | 35,549 psi | 69% | 2408 fps | 97.7% |
| ADI AR 2209 | <<locked>> | 90% | 42,235 psi | 82% | 2549 fps | 95% |
| Alliant Power Pro Varmint | <<locked>> | 90% | 42,496 psi | 83% | 2556 fps | 95.2% |
| Alliant Reloder-16 | <<locked>> | 80% | 34,969 psi | 68% | 2418 fps | 97.9% |
| Alliant Reloder-17 | <<locked>> | 80% | 39,392 psi | 77% | 2539 fps | 99.8% |
| Alliant Reloder-19 | <<locked>> | 90% | 42,003 psi | 82% | 2549 fps | 95.1% |
| Alliant Reloder-22 | <<locked>> | 94% | 41,930 psi | 81% | 2592 fps | 95.3% |
| Alliant Reloder-23 | <<locked>> | 80% | 25,614 psi | 50% | 2188 fps | 95.2% |
| Alliant Reloder-25 | <<locked>> | 92% | 32,822 psi | 64% | 2402 fps | 95.3% |
| Alliant Reloder-26 | 43.5 gr | 84% | 31,096 psi | 60% | 2402 fps | 95.5% |
| Bofors RP5 | <<locked>> | 94% | 41,930 psi | 81% | 2592 fps | 95.3% |
| Bofors RP7 | <<locked>> | 80% | 39,943 psi | 78% | 2428 fps | 95.7% |
| Hodgdon H414 | <<locked>> | 80% | 37,536 psi | 73% | 2451 fps | 95.6% |
| Hodgdon H4350 | <<locked>> | 80% | 40,799 psi | 79% | 2477 fps | 95.1% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 32,590 psi | 63% | 2323 fps | 98.5% |
| Hodgdon Superformance | <<locked>> | 82% | 39,305 psi | 76% | 2520 fps | 95.6% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,166 psi | 53% | 1483 fps | 100% |
| IMR 4350 | <<locked>> | 82% | 38,072 psi | 74% | 2411 fps | 95.1% |
| IMR 4451 Enduron | <<locked>> | 80% | 41,452 psi | 81% | 2461 fps | 96.6% |
| IMR 4831 | <<locked>> | 80% | 34,418 psi | 67% | 2369 fps | 97.5% |
| Lovex S065 | <<locked>> | 80% | 38,957 psi | 76% | 2411 fps | 97.4% |
| Lovex S070 | <<locked>> | 80% | 37,101 psi | 72% | 2392 fps | 95.6% |
| Lovex S071 | <<locked>> | 92% | 33,011 psi | 64% | 2339 fps | 95% |
| Norma 204 | <<locked>> | 86% | 42,888 psi | 83% | 2543 fps | 95.1% |
| Norma MRP | 45.2 gr | 90% | 38,348 psi | 74% | 2546 fps | 95.6% |
| Norma URP | <<locked>> | 80% | 35,563 psi | 69% | 2408 fps | 97.6% |
| Ramshot Hunter | <<locked>> | 80% | 34,519 psi | 67% | 2392 fps | 95.4% |
| Ramshot Magnum | <<locked>> | 98% | 41,292 psi | 80% | 2562 fps | 95.7% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,499 psi | 53% | 1516 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 41,887 psi | 81% | 2592 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 35,375 psi | 69% | 2428 fps | 97.4% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 34,664 psi | 67% | 2431 fps | 96.6% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 38,174 psi | 74% | 2569 fps | 95.2% |
| Rottweil R 903 | <<locked>> | 80% | 42,554 psi | 83% | 2500 fps | 99.9% |
| Rottweil R 905 | <<locked>> | 90% | 40,698 psi | 79% | 2526 fps | 95% |
| Rottweil R 907 | <<locked>> | 80% | 39,943 psi | 78% | 2428 fps | 95.7% |
| Shooters World Long Rifle | <<locked>> | 80% | 38,957 psi | 76% | 2411 fps | 97.4% |
| Shooters World SW4350 | <<locked>> | 80% | 37,101 psi | 72% | 2392 fps | 95.6% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 38,014 psi | 74% | 2356 fps | 95.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 92% | 43,221 psi | 84% | 2579 fps | 95.7% |
| Somchem S355 | <<locked>> | 80% | 42,989 psi | 83% | 2500 fps | 99.9% |
| Somchem S365 | <<locked>> | 80% | 32,039 psi | 62% | 2365 fps | 99.4% |
| Somchem S385 | <<locked>> | 88% | 39,015 psi | 76% | 2464 fps | 95.3% |
| Vihtavuori N150 | <<locked>> | 80% | 40,959 psi | 80% | 2434 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 36,883 psi | 72% | 2405 fps | 97.9% |
| Vihtavuori N165 | <<locked>> | 94% | 40,785 psi | 79% | 2490 fps | 95.5% |
| Vihtavuori N550 | <<locked>> | 80% | 36,506 psi | 71% | 2408 fps | 97.6% |
| Vihtavuori N555 | <<locked>> | 80% | 27,978 psi | 54% | 2260 fps | 95.5% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 36,274 psi | 70% | 2382 fps | 99.4% |
| Winchester 760 | <<locked>> | 80% | 37,811 psi | 73% | 2457 fps | 95.7% |
| Winchester StaBALL HD | 41.8 gr | 84% | 25,686 psi | 50% | 2267 fps | 96% |
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 52 powders for 6.5 x 58 mm Mauser Port. loaded with the .263 | 139gr | Prvi Partizan FMJ BT. Winchester StaBALL HD delivers the highest muzzle velocity at 2,746 fps; across all powders the maximum-charge window runs from 1,660 fps to 2,746 fps. Alliant Reloder-25 gives the best case fill at 100 %, and 52 of the 52 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (355 MPa), the top charges use 70–90 %, leaving at least 10 % headroom. The 139.0 gr projectile in 0.263" calls for a 1:10.0 twist; slower twists will usually not stabilise this weight. Alliant Reloder-25, Hodgdon TrailBoss, Lovex S071 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, Norma MRP, Winchester StaBALL HD rank at the top here: for 6.5 x 58 mm Mauser Port. with the .263 | 139gr | Prvi Partizan FMJ 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.