Load Specifications
Load data in caliber 7.5 x 55 Swiss with .308 | 180gr | Peregrine VRG-3 bullet and 94 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-17, ReloadSwiss RS 60 and Hodgdon H414.
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: 31"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 82% | 47,718 psi | 87% | 2582 fps | 100% |
| Accurate 2495 | <<locked>> | 88% | 48,414 psi | 88% | 2644 fps | 100% |
| Accurate 2520 | <<locked>> | 82% | 47,340 psi | 86% | 2664 fps | 100% |
| Accurate 2700 | <<locked>> | 88% | 48,762 psi | 88% | 2648 fps | 97.1% |
| Accurate 3100ᴾ | <<locked>> | 100% | 35,955 psi | 65% | 2546 fps | 96.2% |
| Accurate 4064 | <<locked>> | 90% | 48,472 psi | 88% | 2694 fps | 100% |
| Accurate 4350 | <<locked>> | 98% | 47,688 psi | 87% | 2772 fps | 99.7% |
| ADI AR 2206H | <<locked>> | 84% | 47,036 psi | 85% | 2684 fps | 99.9% |
| ADI AR 2208 | <<locked>> | 90% | 48,182 psi | 87% | 2687 fps | 99.8% |
| ADI Benchmark 8208 | <<locked>> | 84% | 49,385 psi | 90% | 2684 fps | 100% |
| Alliant AR-Comp | <<locked>> | 84% | 49,342 psi | 90% | 2651 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 88% | 49,385 psi | 90% | 2844 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 90% | 47,543 psi | 86% | 2703 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 88% | 48,080 psi | 87% | 2723 fps | 99.9% |
| Alliant Reloder-16 | <<locked>> | 98% | 47,195 psi | 86% | 2785 fps | 99.8% |
| Alliant Reloder-17 | <<locked>> | 94% | 47,485 psi | 86% | 2818 fps | 100% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 35,186 psi | 64% | 2582 fps | 99.1% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 38,841 psi | 70% | 2730 fps | 98.4% |
| Baschieri & Pellagri 107 | <<locked>> | 86% | 49,530 psi | 90% | 2746 fps | 99.8% |
| Bofors RP3 | <<locked>> | 90% | 47,456 psi | 86% | 2717 fps | 100% |
| Bofors RP7 | <<locked>> | 94% | 48,443 psi | 88% | 2687 fps | 97.4% |
| Hodgdon Benchmark | <<locked>> | 82% | 48,356 psi | 88% | 2621 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 84% | 48,022 psi | 87% | 2710 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 82% | 49,864 psi | 90% | 2808 fps | 100% |
| Hodgdon H380 | <<locked>> | 90% | 48,660 psi | 88% | 2726 fps | 99.5% |
| Hodgdon H414 | <<locked>> | 96% | 47,935 psi | 87% | 2776 fps | 98.1% |
| Hodgdon H4350 | <<locked>> | 94% | 49,095 psi | 89% | 2736 fps | 96.9% |
| Hodgdon H4895 | <<locked>> | 84% | 47,442 psi | 86% | 2694 fps | 100% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 46,035 psi | 84% | 2707 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 88% | 49,472 psi | 90% | 2772 fps | 100% |
| Hodgdon Superformance | <<locked>> | 96% | 48,515 psi | 88% | 2805 fps | 97.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 34,882 psi | 63% | 1650 fps | 100% |
| Hodgdon VARGET | <<locked>> | 86% | 48,689 psi | 88% | 2694 fps | 100% |
| IMR 3031 | <<locked>> | 84% | 46,992 psi | 85% | 2674 fps | 100% |
| IMR 4064 | <<locked>> | 88% | 47,427 psi | 86% | 2664 fps | 99.8% |
| IMR 4166 Enduron | <<locked>> | 86% | 47,805 psi | 87% | 2644 fps | 97.7% |
| IMR 4350 | <<locked>> | 98% | 48,283 psi | 88% | 2710 fps | 97.4% |
| IMR 4451 Enduron | <<locked>> | 92% | 47,529 psi | 86% | 2674 fps | 97.6% |
| IMR 4831ᴾ | <<locked>> | 100% | 48,631 psi | 88% | 2766 fps | 99.8% |
| IMR 4895 | <<locked>> | 88% | 49,284 psi | 89% | 2753 fps | 100% |
| IMR 8208 XBR | <<locked>> | 84% | 49,385 psi | 90% | 2684 fps | 100% |
| Lovex D073.6 | <<locked>> | 86% | 49,008 psi | 89% | 2700 fps | 100% |
| Lovex S060 | <<locked>> | 84% | 47,297 psi | 86% | 2615 fps | 99.9% |
| Lovex S062 | <<locked>> | 88% | 46,992 psi | 85% | 2661 fps | 100% |
| Lovex S065 | <<locked>> | 96% | 49,168 psi | 89% | 2710 fps | 99% |
| Lovex S070 | <<locked>> | 98% | 49,705 psi | 90% | 2740 fps | 98.4% |
| Norma 201 | <<locked>> | 86% | 48,936 psi | 89% | 2677 fps | 100% |
| Norma 202 | <<locked>> | 86% | 49,284 psi | 89% | 2677 fps | 100% |
| Norma 203B | <<locked>> | 88% | 47,311 psi | 86% | 2710 fps | 100% |
| Norma 204 | <<locked>> | 98% | 48,588 psi | 88% | 2753 fps | 96.2% |
| Norma URP | <<locked>> | 98% | 47,427 psi | 86% | 2766 fps | 99.6% |
| Ramshot Big Game | <<locked>> | 88% | 47,500 psi | 86% | 2736 fps | 99.9% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 49,821 psi | 90% | 2815 fps | 99% |
| Ramshot TAC | <<locked>> | 84% | 49,574 psi | 90% | 2703 fps | 99.1% |
| Ramshot Wild Boar | <<locked>> | 84% | 48,704 psi | 88% | 2717 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 35,404 psi | 64% | 1693 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 90% | 49,313 psi | 89% | 2710 fps | 98.5% |
| ReloadSwiss RS 52 | <<locked>> | 86% | 47,747 psi | 87% | 2779 fps | 99.9% |
| ReloadSwiss RS 60 | <<locked>> | 92% | 47,413 psi | 86% | 2815 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 98% | 47,471 psi | 86% | 2795 fps | 99.6% |
| ReloadSwiss RS 70 | <<locked>> | 98% | 48,022 psi | 87% | 2825 fps | 99.4% |
| Rottweil R 901 | <<locked>> | 82% | 46,978 psi | 85% | 2612 fps | 100% |
| Rottweil R 902 | <<locked>> | 88% | 49,182 psi | 89% | 2671 fps | 100% |
| Rottweil R 903 | <<locked>> | 92% | 47,297 psi | 86% | 2707 fps | 100% |
| Rottweil R 907 | <<locked>> | 94% | 48,443 psi | 88% | 2687 fps | 97.4% |
| Shooters World Long Rifle | <<locked>> | 96% | 49,168 psi | 89% | 2710 fps | 99% |
| Shooters World Match Rifle | <<locked>> | 86% | 49,008 psi | 89% | 2700 fps | 100% |
| Shooters World Precision | <<locked>> | 88% | 46,992 psi | 85% | 2661 fps | 100% |
| Shooters World SW4350 | <<locked>> | 98% | 49,705 psi | 90% | 2740 fps | 98.4% |
| SNPE Vectan SP 11 | <<locked>> | 92% | 49,081 psi | 89% | 2769 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 84% | 47,384 psi | 86% | 2674 fps | 99.2% |
| SNPE Vectan SP 9 | <<locked>> | 86% | 48,443 psi | 88% | 2703 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 84% | 47,761 psi | 87% | 2572 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 90% | 47,674 psi | 87% | 2575 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 96% | 49,647 psi | 90% | 2664 fps | 98% |
| Somchem S335 | <<locked>> | 84% | 46,920 psi | 85% | 2572 fps | 100% |
| Somchem S341 | <<locked>> | 84% | 47,326 psi | 86% | 2671 fps | 99.9% |
| Somchem S355 | <<locked>> | 92% | 48,182 psi | 87% | 2707 fps | 100% |
| Somchem S365ᴾ | <<locked>> | 100% | 45,295 psi | 82% | 2766 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 42,047 psi | 76% | 2648 fps | 96.1% |
| Vihtavuori N133 | <<locked>> | 84% | 48,037 psi | 87% | 2562 fps | 100% |
| Vihtavuori N135 | <<locked>> | 88% | 48,834 psi | 89% | 2638 fps | 100% |
| Vihtavuori N140 | <<locked>> | 88% | 49,806 psi | 90% | 2657 fps | 100% |
| Vihtavuori N150 | <<locked>> | 94% | 49,516 psi | 90% | 2687 fps | 100% |
| Vihtavuori N160 | <<locked>> | 96% | 47,021 psi | 85% | 2713 fps | 99.5% |
| Vihtavuori N530 | <<locked>> | 84% | 49,661 psi | 90% | 2680 fps | 100% |
| Vihtavuori N540 | <<locked>> | 88% | 47,950 psi | 87% | 2657 fps | 100% |
| Vihtavuori N550 | <<locked>> | 98% | 48,921 psi | 89% | 2769 fps | 99.6% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 37,768 psi | 69% | 2651 fps | 99% |
| Winchester 6.5 StaBALL | <<locked>> | 96% | 47,297 psi | 86% | 2694 fps | 100% |
| Winchester 748 | <<locked>> | 84% | 49,226 psi | 89% | 2730 fps | 100% |
| Winchester 760 | <<locked>> | 96% | 47,935 psi | 87% | 2776 fps | 98.1% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 31,328 psi | 57% | 2582 fps | 99% |
| Winchester StaBALL Match | <<locked>> | 86% | 48,008 psi | 87% | 2710 fps | 100% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 31"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 80% | 44,817 psi | 81% | 2539 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 37,173 psi | 67% | 2470 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 44,208 psi | 80% | 2618 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 42,743 psi | 78% | 2543 fps | 95.7% |
| Accurate 3100 | <<locked>> | 98% | 33,402 psi | 61% | 2490 fps | 95.4% |
| Accurate 4064 | <<locked>> | 80% | 35,157 psi | 64% | 2470 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 29,037 psi | 53% | 2402 fps | 95.7% |
| ADI AR 2206H | <<locked>> | 80% | 41,394 psi | 75% | 2585 fps | 99.5% |
| ADI AR 2208 | <<locked>> | 80% | 35,114 psi | 64% | 2441 fps | 98% |
| ADI Benchmark 8208 | <<locked>> | 80% | 43,526 psi | 79% | 2589 fps | 100% |
| Alliant AR-Comp | <<locked>> | 80% | 43,221 psi | 78% | 2566 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 37,260 psi | 68% | 2615 fps | 98.5% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 34,476 psi | 63% | 2464 fps | 99.1% |
| Alliant Reloder-15 | <<locked>> | 80% | 37,173 psi | 67% | 2523 fps | 98.6% |
| Alliant Reloder-16 | <<locked>> | 82% | 28,601 psi | 52% | 2369 fps | 95% |
| Alliant Reloder-17 | 44.5 gr | 80% | 29,718 psi | 54% | 2438 fps | 97.6% |
| Alliant Reloder-23 | <<locked>> | 90% | 25,860 psi | 47% | 2326 fps | 95.5% |
| Alliant Reloder-26 | <<locked>> | 94% | 31,531 psi | 57% | 2549 fps | 95.7% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 40,422 psi | 73% | 2589 fps | 98.8% |
| Bofors RP3 | <<locked>> | 80% | 33,663 psi | 61% | 2464 fps | 99.1% |
| Bofors RP7 | <<locked>> | 88% | 40,132 psi | 73% | 2539 fps | 95.4% |
| Hodgdon Benchmark | <<locked>> | 80% | 45,310 psi | 82% | 2575 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 41,742 psi | 76% | 2608 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 80% | 46,238 psi | 84% | 2749 fps | 99.8% |
| Hodgdon H380 | <<locked>> | 80% | 34,780 psi | 63% | 2467 fps | 96.9% |
| Hodgdon H414 | 47.8 gr | 88% | 36,622 psi | 66% | 2559 fps | 95.2% |
| Hodgdon H4350 | <<locked>> | 90% | 43,221 psi | 78% | 2638 fps | 95.5% |
| Hodgdon H4895 | <<locked>> | 80% | 41,771 psi | 76% | 2595 fps | 99.8% |
| Hodgdon Hybrid 100V | <<locked>> | 82% | 25,904 psi | 47% | 2270 fps | 95.8% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 37,681 psi | 68% | 2569 fps | 99.7% |
| Hodgdon Superformance | <<locked>> | 90% | 39,218 psi | 71% | 2631 fps | 95.2% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,034 psi | 47% | 1480 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 40,045 psi | 73% | 2546 fps | 99.6% |
| IMR 3031 | <<locked>> | 80% | 41,234 psi | 75% | 2585 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 36,840 psi | 67% | 2470 fps | 98.6% |
| IMR 4166 Enduron | <<locked>> | 80% | 39,523 psi | 72% | 2493 fps | 95.7% |
| IMR 4350 | <<locked>> | 92% | 40,118 psi | 73% | 2566 fps | 95.4% |
| IMR 4451 Enduron | <<locked>> | 86% | 39,363 psi | 71% | 2523 fps | 95.6% |
| IMR 4831 | <<locked>> | 84% | 28,572 psi | 52% | 2365 fps | 95.5% |
| IMR 4895 | <<locked>> | 80% | 38,072 psi | 69% | 2552 fps | 99.2% |
| IMR 8208 XBR | <<locked>> | 80% | 43,526 psi | 79% | 2589 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 40,059 psi | 73% | 2559 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 41,713 psi | 76% | 2520 fps | 99.5% |
| Lovex S062 | <<locked>> | 80% | 36,535 psi | 66% | 2474 fps | 99.6% |
| Lovex S065 | <<locked>> | 84% | 33,881 psi | 61% | 2418 fps | 95.6% |
| Lovex S070 | <<locked>> | 88% | 36,318 psi | 66% | 2493 fps | 95.2% |
| Norma 201 | <<locked>> | 80% | 40,451 psi | 73% | 2536 fps | 99.9% |
| Norma 202 | <<locked>> | 80% | 40,727 psi | 74% | 2543 fps | 100% |
| Norma 203B | <<locked>> | 80% | 36,521 psi | 66% | 2513 fps | 98.9% |
| Norma 204 | <<locked>> | 96% | 45,411 psi | 82% | 2700 fps | 95.4% |
| Norma URP | <<locked>> | 84% | 30,052 psi | 55% | 2408 fps | 95.8% |
| Ramshot Big Game | <<locked>> | 80% | 35,853 psi | 65% | 2523 fps | 98.7% |
| Ramshot Hunter | <<locked>> | 88% | 33,634 psi | 61% | 2497 fps | 95% |
| Ramshot TAC | <<locked>> | 80% | 43,337 psi | 79% | 2598 fps | 98.2% |
| Ramshot Wild Boar | <<locked>> | 80% | 42,714 psi | 78% | 2618 fps | 99.7% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,339 psi | 48% | 1516 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 35,476 psi | 64% | 2454 fps | 95.3% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 38,754 psi | 70% | 2621 fps | 99% |
| ReloadSwiss RS 60 | 44.5 gr | 80% | 31,705 psi | 58% | 2503 fps | 99.8% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 29,211 psi | 53% | 2418 fps | 95.1% |
| ReloadSwiss RS 70 | <<locked>> | 86% | 31,937 psi | 58% | 2480 fps | 95.2% |
| Rottweil R 901 | <<locked>> | 80% | 44,251 psi | 80% | 2569 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 38,464 psi | 70% | 2490 fps | 99.8% |
| Rottweil R 903 | <<locked>> | 80% | 31,647 psi | 57% | 2408 fps | 98.4% |
| Rottweil R 907 | <<locked>> | 88% | 40,132 psi | 73% | 2539 fps | 95.4% |
| Shooters World Long Rifle | <<locked>> | 84% | 33,881 psi | 61% | 2418 fps | 95.6% |
| Shooters World Match Rifle | <<locked>> | 80% | 40,059 psi | 73% | 2559 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 36,535 psi | 66% | 2474 fps | 99.6% |
| Shooters World SW4350 | <<locked>> | 88% | 36,318 psi | 66% | 2493 fps | 95.2% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 32,982 psi | 60% | 2464 fps | 98.1% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 41,408 psi | 75% | 2572 fps | 98.4% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 39,987 psi | 73% | 2556 fps | 99.4% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 42,134 psi | 76% | 2487 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 34,766 psi | 63% | 2365 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 37,724 psi | 68% | 2464 fps | 95.4% |
| Somchem S335 | <<locked>> | 80% | 41,626 psi | 76% | 2490 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 41,162 psi | 75% | 2569 fps | 99.5% |
| Somchem S355 | <<locked>> | 80% | 32,851 psi | 60% | 2421 fps | 98.5% |
| Somchem S365 | <<locked>> | 80% | 23,438 psi | 43% | 2254 fps | 96.2% |
| Somchem S385 | <<locked>> | 98% | 39,450 psi | 72% | 2598 fps | 95.3% |
| Vihtavuori N133 | <<locked>> | 80% | 42,438 psi | 77% | 2477 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 37,782 psi | 69% | 2470 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 38,464 psi | 70% | 2480 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 31,053 psi | 56% | 2356 fps | 99.1% |
| Vihtavuori N160 | <<locked>> | 82% | 29,443 psi | 53% | 2359 fps | 95.3% |
| Vihtavuori N530 | <<locked>> | 80% | 43,337 psi | 79% | 2582 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 36,985 psi | 67% | 2474 fps | 100% |
| Vihtavuori N550 | <<locked>> | 82% | 28,863 psi | 52% | 2362 fps | 95% |
| Vihtavuori N555 | <<locked>> | 90% | 27,195 psi | 49% | 2395 fps | 95.6% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 27,746 psi | 50% | 2290 fps | 96.8% |
| Winchester 748 | <<locked>> | 80% | 42,931 psi | 78% | 2631 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 36,854 psi | 67% | 2566 fps | 95.3% |
| Winchester StaBALL HD | <<locked>> | 94% | 25,788 psi | 47% | 2395 fps | 95.9% |
| Winchester StaBALL Match | <<locked>> | 80% | 39,233 psi | 71% | 2559 fps | 99.6% |
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 112 powders for 7.5 x 55 Swiss loaded with the .308 | 180gr | Peregrine VRG-3. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 2,844 fps; across all powders the maximum-charge window runs from 1,650 fps to 2,844 fps. Accurate 3100 gives the best case fill at 100 %, and 112 of the 112 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (380 MPa), the top charges use 54–90 %, leaving at least 10 % headroom. The 180.0 gr projectile in 0.308" calls for a 1:13.0 twist; slower twists will usually not stabilise this weight. Accurate 3100, ADI AR 2209, Alliant Reloder-19 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-17, ReloadSwiss RS 60, Hodgdon H414 rank at the top here: for 7.5 x 55 Swiss with the .308 | 180gr | Peregrine VRG-3 they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Alliant Reloder-22, Alliant Reloder-25, Bofors RP15 burn incompletely and react more sensitively to barrel length and temperature. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.