Load Specifications
Load data in caliber 6.5 x 58 mm Mauser Port. with .263 | 139gr | Prvi Partizan SP BT bullet and 53 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Norma MRP, Alliant Reloder-26 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% | 45,034 psi | 87% | 2582 fps | 98.5% |
| Accurate 4350 | <<locked>> | 86% | 44,208 psi | 86% | 2582 fps | 99.4% |
| ADI AR 2209 | <<locked>> | 92% | 45,252 psi | 88% | 2612 fps | 96% |
| Alliant Power Pro Varmint | <<locked>> | 92% | 45,469 psi | 88% | 2615 fps | 96.1% |
| Alliant Reloder-16 | <<locked>> | 88% | 45,324 psi | 88% | 2638 fps | 99.8% |
| Alliant Reloder-17 | <<locked>> | 84% | 45,614 psi | 89% | 2657 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 92% | 44,918 psi | 87% | 2608 fps | 96.1% |
| Alliant Reloder-22 | <<locked>> | 96% | 44,947 psi | 87% | 2651 fps | 96.2% |
| Alliant Reloder-23 | <<locked>> | 98% | 45,600 psi | 89% | 2661 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 42,351 psi | 82% | 2631 fps | 98.7% |
| Alliant Reloder-26 | <<locked>> | 94% | 44,701 psi | 87% | 2717 fps | 99.6% |
| Bofors RP15 | <<locked>> | 98% | 44,309 psi | 86% | 2638 fps | 95.9% |
| Bofors RP5 | <<locked>> | 96% | 44,947 psi | 87% | 2651 fps | 96.2% |
| Bofors RP7 | <<locked>> | 84% | 45,716 psi | 89% | 2539 fps | 97.3% |
| Hodgdon H414 | <<locked>> | 86% | 46,369 psi | 90% | 2628 fps | 98% |
| Hodgdon H4350 | <<locked>> | 84% | 46,369 psi | 90% | 2589 fps | 96.7% |
| Hodgdon Hybrid 100V | <<locked>> | 90% | 45,455 psi | 88% | 2575 fps | 100% |
| Hodgdon Superformance | <<locked>> | 86% | 45,542 psi | 88% | 2648 fps | 97.5% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,245 psi | 70% | 1663 fps | 100% |
| IMR 4350 | <<locked>> | 88% | 46,166 psi | 90% | 2569 fps | 97.4% |
| IMR 4451 Enduron | <<locked>> | 82% | 44,382 psi | 86% | 2516 fps | 97.4% |
| IMR 4831 | <<locked>> | 88% | 45,049 psi | 87% | 2582 fps | 99.6% |
| Lovex S065 | <<locked>> | 84% | 44,222 psi | 86% | 2516 fps | 98.6% |
| Lovex S070 | <<locked>> | 86% | 45,020 psi | 87% | 2549 fps | 97.8% |
| Lovex S071ᴾ | <<locked>> | 100% | 42,888 psi | 83% | 2546 fps | 98.1% |
| Norma 204 | <<locked>> | 88% | 45,992 psi | 89% | 2605 fps | 96.1% |
| Norma MRP | <<locked>> | 94% | 44,237 psi | 86% | 2671 fps | 97.5% |
| Norma URP | <<locked>> | 88% | 46,586 psi | 90% | 2625 fps | 99.6% |
| Ramshot Hunter | <<locked>> | 88% | 45,179 psi | 88% | 2615 fps | 98.5% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 44,614 psi | 87% | 2628 fps | 96.7% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,854 psi | 72% | 1699 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 82% | 45,295 psi | 88% | 2654 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 86% | 43,918 psi | 85% | 2602 fps | 99.2% |
| ReloadSwiss RS 70 | <<locked>> | 88% | 45,614 psi | 89% | 2667 fps | 99.4% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 41,089 psi | 80% | 2641 fps | 96.6% |
| Rottweil R 903 | <<locked>> | 82% | 45,716 psi | 89% | 2556 fps | 100% |
| Rottweil R 905 | <<locked>> | 92% | 43,758 psi | 85% | 2589 fps | 95.9% |
| Rottweil R 907 | <<locked>> | 84% | 45,716 psi | 89% | 2539 fps | 97.3% |
| Shooters World Long Rifle | <<locked>> | 84% | 44,222 psi | 86% | 2516 fps | 98.6% |
| Shooters World SW4350 | <<locked>> | 86% | 45,020 psi | 87% | 2549 fps | 97.8% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 46,543 psi | 90% | 2520 fps | 98% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 46,470 psi | 90% | 2638 fps | 96.6% |
| Somchem S355 | <<locked>> | 82% | 46,108 psi | 90% | 2556 fps | 100% |
| Somchem S365 | <<locked>> | 90% | 45,440 psi | 88% | 2631 fps | 100% |
| Somchem S385 | <<locked>> | 92% | 44,686 psi | 87% | 2575 fps | 97% |
| Vihtavuori N150 | <<locked>> | 82% | 43,990 psi | 85% | 2487 fps | 100% |
| Vihtavuori N160 | <<locked>> | 86% | 45,411 psi | 88% | 2569 fps | 99.5% |
| Vihtavuori N165 | <<locked>> | 96% | 43,700 psi | 85% | 2546 fps | 96.3% |
| Vihtavuori N550 | <<locked>> | 86% | 44,657 psi | 87% | 2572 fps | 99.3% |
| Vihtavuori N555 | <<locked>> | 94% | 44,875 psi | 87% | 2631 fps | 99.8% |
| Winchester 6.5 StaBALL | <<locked>> | 86% | 44,425 psi | 86% | 2539 fps | 100% |
| Winchester 760 | <<locked>> | 86% | 46,369 psi | 90% | 2628 fps | 98% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 43,613 psi | 85% | 2756 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% | 34,316 psi | 67% | 2372 fps | 95.6% |
| Accurate 4350 | <<locked>> | 80% | 35,984 psi | 70% | 2418 fps | 97.9% |
| ADI AR 2209 | <<locked>> | 90% | 42,627 psi | 83% | 2559 fps | 95.2% |
| Alliant Power Pro Varmint | <<locked>> | 90% | 42,583 psi | 83% | 2559 fps | 95.3% |
| Alliant Reloder-16 | <<locked>> | 80% | 35,331 psi | 69% | 2431 fps | 98% |
| Alliant Reloder-17 | <<locked>> | 80% | 39,798 psi | 77% | 2549 fps | 99.8% |
| Alliant Reloder-19 | <<locked>> | 90% | 42,090 psi | 82% | 2552 fps | 95.2% |
| Alliant Reloder-22 | <<locked>> | 94% | 42,018 psi | 82% | 2595 fps | 95.4% |
| Alliant Reloder-23 | <<locked>> | 80% | 25,759 psi | 50% | 2192 fps | 95.4% |
| Alliant Reloder-25 | <<locked>> | 92% | 32,909 psi | 64% | 2408 fps | 95.4% |
| Alliant Reloder-26 | 43.8 gr | 84% | 31,415 psi | 61% | 2411 fps | 95.8% |
| Bofors RP15 | <<locked>> | 96% | 41,452 psi | 81% | 2582 fps | 95% |
| Bofors RP5 | <<locked>> | 94% | 42,018 psi | 82% | 2595 fps | 95.4% |
| Bofors RP7 | <<locked>> | 80% | 40,350 psi | 78% | 2438 fps | 95.8% |
| Hodgdon H414 | <<locked>> | 80% | 37,956 psi | 74% | 2464 fps | 95.8% |
| Hodgdon H4350 | <<locked>> | 80% | 40,973 psi | 80% | 2484 fps | 95.2% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 32,750 psi | 64% | 2329 fps | 98.5% |
| Hodgdon Superformance | <<locked>> | 82% | 39,639 psi | 77% | 2530 fps | 95.8% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,238 psi | 53% | 1486 fps | 100% |
| IMR 4350 | <<locked>> | 82% | 38,203 psi | 74% | 2415 fps | 95.1% |
| IMR 4451 Enduron | <<locked>> | 80% | 41,597 psi | 81% | 2464 fps | 96.7% |
| IMR 4831 | <<locked>> | 80% | 34,592 psi | 67% | 2375 fps | 97.6% |
| Lovex S065 | <<locked>> | 80% | 39,088 psi | 76% | 2415 fps | 97.4% |
| Lovex S070 | <<locked>> | 80% | 37,246 psi | 72% | 2395 fps | 95.7% |
| Lovex S071 | <<locked>> | 92% | 33,388 psi | 65% | 2349 fps | 95.2% |
| Norma 204 | <<locked>> | 86% | 43,004 psi | 84% | 2549 fps | 95.2% |
| Norma MRP | 45.5 gr | 90% | 38,696 psi | 75% | 2556 fps | 95.8% |
| Norma URP | <<locked>> | 80% | 35,737 psi | 69% | 2411 fps | 97.7% |
| Ramshot Hunter | <<locked>> | 80% | 34,664 psi | 67% | 2398 fps | 95.5% |
| Ramshot Magnum | <<locked>> | 98% | 41,611 psi | 81% | 2572 fps | 95.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,586 psi | 54% | 1519 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 42,337 psi | 82% | 2602 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 35,534 psi | 69% | 2434 fps | 97.5% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 34,780 psi | 68% | 2438 fps | 96.7% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 38,435 psi | 75% | 2575 fps | 95.4% |
| Rottweil R 903 | <<locked>> | 80% | 42,699 psi | 83% | 2503 fps | 99.9% |
| Rottweil R 905 | <<locked>> | 90% | 41,147 psi | 80% | 2536 fps | 95.1% |
| Rottweil R 907 | <<locked>> | 80% | 40,350 psi | 78% | 2438 fps | 95.8% |
| Shooters World Long Rifle | <<locked>> | 80% | 39,088 psi | 76% | 2415 fps | 97.4% |
| Shooters World SW4350 | <<locked>> | 80% | 37,246 psi | 72% | 2395 fps | 95.7% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 38,421 psi | 75% | 2365 fps | 95.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 40,756 psi | 79% | 2533 fps | 95% |
| Somchem S355 | <<locked>> | 80% | 43,178 psi | 84% | 2503 fps | 99.9% |
| Somchem S365 | <<locked>> | 80% | 32,401 psi | 63% | 2375 fps | 99.4% |
| Somchem S385 | <<locked>> | 88% | 39,117 psi | 76% | 2467 fps | 95.4% |
| Vihtavuori N150 | <<locked>> | 80% | 41,104 psi | 80% | 2438 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 37,304 psi | 72% | 2415 fps | 98.1% |
| Vihtavuori N165 | <<locked>> | 94% | 41,133 psi | 80% | 2500 fps | 95.6% |
| Vihtavuori N550 | <<locked>> | 80% | 36,666 psi | 71% | 2415 fps | 97.7% |
| Vihtavuori N555 | <<locked>> | 80% | 28,108 psi | 55% | 2267 fps | 95.6% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 36,376 psi | 71% | 2385 fps | 99.5% |
| Winchester 760 | <<locked>> | 80% | 37,956 psi | 74% | 2464 fps | 95.8% |
| Winchester StaBALL HD | 42 gr | 84% | 25,788 psi | 50% | 2270 fps | 96.1% |
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 53 powders for 6.5 x 58 mm Mauser Port. loaded with the .263 | 139gr | Prvi Partizan SP BT. Winchester StaBALL HD delivers the highest muzzle velocity at 2,756 fps; across all powders the maximum-charge window runs from 1,663 fps to 2,756 fps. Alliant Reloder-25 gives the best case fill at 100 %, and 53 of the 53 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 1:10.5 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. Norma MRP, Alliant Reloder-26, Winchester StaBALL HD rank at the top here: for 6.5 x 58 mm Mauser Port. with the .263 | 139gr | Prvi Partizan SP 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.