Load Specifications
Load data in caliber .30-06 Spring. with .308 | 166gr | Hammer Stone Hammer bullet and 93 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ReloadSwiss RS 60, Alliant Power Pro 2000-MR and Alliant Reloder-17.
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: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 86% | 51,343 psi | 87% | 2635 fps | 100% |
| Accurate 2460 | <<locked>> | 84% | 53,156 psi | 90% | 2703 fps | 100% |
| Accurate 2495 | <<locked>> | 92% | 52,040 psi | 89% | 2690 fps | 100% |
| Accurate 2520 | <<locked>> | 86% | 51,401 psi | 88% | 2713 fps | 100% |
| Accurate 4064 | <<locked>> | 94% | 51,996 psi | 89% | 2733 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 47,776 psi | 81% | 2736 fps | 98.1% |
| ADI AR 2206H | <<locked>> | 88% | 50,662 psi | 86% | 2717 fps | 99.3% |
| ADI AR 2208 | <<locked>> | 94% | 51,793 psi | 88% | 2717 fps | 99% |
| ADI Benchmark 8208 | <<locked>> | 86% | 50,038 psi | 85% | 2677 fps | 99.8% |
| Alliant AR-Comp | <<locked>> | 88% | 53,156 psi | 90% | 2707 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 82% | 51,300 psi | 87% | 2776 fps | 99.7% |
| Alliant Power Pro 2000-MR | <<locked>> | 90% | 49,821 psi | 85% | 2812 fps | 98.8% |
| Alliant Reloder- TS 15.5 | <<locked>> | 94% | 51,126 psi | 87% | 2736 fps | 99.8% |
| Alliant Reloder-10x | <<locked>> | 82% | 51,242 psi | 87% | 2641 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 92% | 51,735 psi | 88% | 2753 fps | 99.1% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 47,500 psi | 81% | 2746 fps | 98.2% |
| Alliant Reloder-17 | <<locked>> | 98% | 51,605 psi | 88% | 2844 fps | 99.8% |
| Baschieri & Pellagri 107 | <<locked>> | 88% | 50,285 psi | 86% | 2726 fps | 98.6% |
| Bofors RP3 | <<locked>> | 94% | 51,198 psi | 87% | 2746 fps | 99.8% |
| Hodgdon Benchmark | <<locked>> | 86% | 52,199 psi | 89% | 2667 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 88% | 52,185 psi | 89% | 2753 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 84% | 50,299 psi | 86% | 2785 fps | 99% |
| Hodgdon H322 | <<locked>> | 82% | 50,357 psi | 86% | 2677 fps | 100% |
| Hodgdon H335 | <<locked>> | 82% | 51,430 psi | 88% | 2700 fps | 100% |
| Hodgdon H380 | <<locked>> | 94% | 52,533 psi | 89% | 2756 fps | 98.3% |
| Hodgdon H414ᴾ | <<locked>> | 100% | 51,416 psi | 88% | 2789 fps | 96.2% |
| Hodgdon H4895 | <<locked>> | 88% | 51,097 psi | 87% | 2730 fps | 99.6% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 43,410 psi | 74% | 2628 fps | 98.7% |
| Hodgdon LEVERevolution | <<locked>> | 90% | 49,850 psi | 85% | 2756 fps | 99.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 34,737 psi | 59% | 1670 fps | 100% |
| Hodgdon VARGET | <<locked>> | 90% | 52,446 psi | 89% | 2733 fps | 99.7% |
| IMR 3031 | <<locked>> | 88% | 50,560 psi | 86% | 2720 fps | 100% |
| IMR 4064 | <<locked>> | 92% | 51,126 psi | 87% | 2700 fps | 99.1% |
| IMR 4166 Enduron | <<locked>> | 90% | 51,808 psi | 88% | 2677 fps | 96% |
| IMR 4198 | <<locked>> | 82% | 51,895 psi | 88% | 2605 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 96% | 51,111 psi | 87% | 2697 fps | 95.8% |
| IMR 4831ᴾ | <<locked>> | 100% | 45,803 psi | 78% | 2684 fps | 97.8% |
| IMR 4895 | <<locked>> | 92% | 53,026 psi | 90% | 2785 fps | 99.6% |
| IMR 8208 XBR | <<locked>> | 86% | 50,038 psi | 85% | 2677 fps | 99.8% |
| Lovex D073.5 | <<locked>> | 82% | 49,574 psi | 84% | 2657 fps | 100% |
| Lovex D073.6 | <<locked>> | 90% | 53,040 psi | 90% | 2746 fps | 100% |
| Lovex S060 | <<locked>> | 88% | 51,010 psi | 87% | 2654 fps | 99.3% |
| Lovex S062 | <<locked>> | 92% | 50,502 psi | 86% | 2697 fps | 99.8% |
| Lovex S065ᴾ | <<locked>> | 100% | 52,910 psi | 90% | 2733 fps | 97.7% |
| Lovex S070ᴾ | <<locked>> | 100% | 50,227 psi | 86% | 2710 fps | 96% |
| Norma 201 | <<locked>> | 90% | 52,489 psi | 89% | 2713 fps | 99.9% |
| Norma 202 | <<locked>> | 90% | 53,127 psi | 90% | 2723 fps | 100% |
| Norma 203B | <<locked>> | 92% | 50,894 psi | 87% | 2743 fps | 99.4% |
| Norma URPᴾ | <<locked>> | 100% | 47,732 psi | 81% | 2733 fps | 98% |
| Ramshot Big Game | <<locked>> | 92% | 51,227 psi | 87% | 2762 fps | 99.3% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 47,065 psi | 80% | 2720 fps | 96% |
| Ramshot TAC | <<locked>> | 86% | 50,314 psi | 86% | 2684 fps | 97.4% |
| Ramshot Wild Boar | <<locked>> | 88% | 52,895 psi | 90% | 2756 fps | 99.5% |
| Ramshot X-Terminator | <<locked>> | 84% | 50,995 psi | 87% | 2674 fps | 99.2% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 34,867 psi | 59% | 1706 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 84% | 52,910 psi | 90% | 2710 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 92% | 49,777 psi | 85% | 2684 fps | 96.3% |
| ReloadSwiss RS 52 | <<locked>> | 90% | 51,590 psi | 88% | 2812 fps | 99.1% |
| ReloadSwiss RS 60 | <<locked>> | 96% | 51,401 psi | 88% | 2848 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 47,529 psi | 81% | 2756 fps | 97.8% |
| ReloadSwiss RS 70ᴾ | <<locked>> | 100% | 48,704 psi | 83% | 2779 fps | 97.3% |
| Rottweil R 901 | <<locked>> | 86% | 50,227 psi | 86% | 2657 fps | 100% |
| Rottweil R 902 | <<locked>> | 92% | 53,026 psi | 90% | 2713 fps | 99.9% |
| Rottweil R 903 | <<locked>> | 96% | 50,734 psi | 86% | 2733 fps | 99.7% |
| Shooters World Long Rifleᴾ | <<locked>> | 100% | 52,910 psi | 90% | 2733 fps | 97.7% |
| Shooters World Match Rifle | <<locked>> | 90% | 53,040 psi | 90% | 2746 fps | 100% |
| Shooters World Precision | <<locked>> | 92% | 50,502 psi | 86% | 2697 fps | 99.8% |
| Shooters World SW4350ᴾ | <<locked>> | 100% | 50,227 psi | 86% | 2710 fps | 96% |
| Shooters World Tactical Rifle | <<locked>> | 82% | 52,475 psi | 89% | 2677 fps | 99.8% |
| SNPE Vectan SP 11 | <<locked>> | 96% | 52,866 psi | 90% | 2795 fps | 99.5% |
| SNPE Vectan SP 3 | <<locked>> | 82% | 52,286 psi | 89% | 2664 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 88% | 51,605 psi | 88% | 2710 fps | 98.1% |
| SNPE Vectan SP 9 | <<locked>> | 90% | 52,373 psi | 89% | 2740 fps | 99.5% |
| SNPE Vectan Tubal 3000 | <<locked>> | 88% | 51,576 psi | 88% | 2625 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 94% | 51,285 psi | 87% | 2618 fps | 100% |
| Somchem S321 | <<locked>> | 84% | 50,792 psi | 86% | 2707 fps | 99.9% |
| Somchem S335 | <<locked>> | 88% | 50,444 psi | 86% | 2618 fps | 100% |
| Somchem S341 | <<locked>> | 88% | 51,343 psi | 87% | 2707 fps | 99.3% |
| Somchem S355 | <<locked>> | 96% | 51,706 psi | 88% | 2736 fps | 99.6% |
| Somchem S365ᴾ | <<locked>> | 100% | 42,380 psi | 72% | 2680 fps | 99.5% |
| Vihtavuori N130 | <<locked>> | 84% | 51,430 psi | 88% | 2595 fps | 100% |
| Vihtavuori N133 | <<locked>> | 88% | 51,706 psi | 88% | 2615 fps | 100% |
| Vihtavuori N135 | <<locked>> | 92% | 52,112 psi | 89% | 2684 fps | 100% |
| Vihtavuori N140 | <<locked>> | 90% | 50,444 psi | 86% | 2657 fps | 100% |
| Vihtavuori N150 | <<locked>> | 98% | 53,113 psi | 90% | 2720 fps | 100% |
| Vihtavuori N160ᴾ | <<locked>> | 100% | 50,328 psi | 86% | 2733 fps | 98.3% |
| Vihtavuori N530 | <<locked>> | 86% | 50,270 psi | 86% | 2674 fps | 99.8% |
| Vihtavuori N540 | <<locked>> | 92% | 51,793 psi | 88% | 2697 fps | 100% |
| Vihtavuori N550ᴾ | <<locked>> | 100% | 49,327 psi | 84% | 2736 fps | 98% |
| Winchester 6.5 StaBALLᴾ | <<locked>> | 100% | 51,503 psi | 88% | 2723 fps | 99.7% |
| Winchester 748 | <<locked>> | 86% | 49,617 psi | 84% | 2717 fps | 100% |
| Winchester 760ᴾ | <<locked>> | 100% | 51,735 psi | 88% | 2792 fps | 96.2% |
| Winchester StaBALL Match | <<locked>> | 90% | 52,083 psi | 89% | 2746 fps | 99.7% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 80% | 42,627 psi | 73% | 2503 fps | 100% |
| Accurate 2460 | <<locked>> | 80% | 46,354 psi | 79% | 2602 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 34,548 psi | 59% | 2405 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 41,597 psi | 71% | 2556 fps | 99.8% |
| Accurate 4064 | <<locked>> | 80% | 32,721 psi | 56% | 2392 fps | 99.1% |
| Accurate 4350 | <<locked>> | 94% | 38,537 psi | 66% | 2569 fps | 95.8% |
| ADI AR 2206H | <<locked>> | 80% | 39,189 psi | 67% | 2510 fps | 97.3% |
| ADI AR 2208 | <<locked>> | 82% | 35,607 psi | 61% | 2415 fps | 95.3% |
| ADI Benchmark 8208 | <<locked>> | 80% | 41,249 psi | 70% | 2526 fps | 98.8% |
| Alliant AR-Comp | <<locked>> | 80% | 40,654 psi | 69% | 2530 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 80% | 47,935 psi | 82% | 2720 fps | 99.4% |
| Alliant Power Pro 2000-MR | 48.1 gr | 82% | 37,753 psi | 64% | 2569 fps | 95.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 32,445 psi | 55% | 2382 fps | 96.1% |
| Alliant Reloder-10x | <<locked>> | 80% | 48,240 psi | 82% | 2598 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 34,998 psi | 60% | 2438 fps | 95.4% |
| Alliant Reloder-16 | <<locked>> | 92% | 36,985 psi | 63% | 2533 fps | 95.1% |
| Alliant Reloder-17 | 48.6 gr | 84% | 32,082 psi | 55% | 2438 fps | 95% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 38,072 psi | 65% | 2503 fps | 95.7% |
| Bofors RP3 | <<locked>> | 80% | 31,633 psi | 54% | 2375 fps | 96% |
| Hodgdon Benchmark | <<locked>> | 80% | 43,221 psi | 74% | 2523 fps | 99.4% |
| Hodgdon BL-C2 | <<locked>> | 80% | 39,537 psi | 67% | 2539 fps | 98.9% |
| Hodgdon CFE223 | <<locked>> | 80% | 43,569 psi | 74% | 2671 fps | 97.8% |
| Hodgdon H322 | <<locked>> | 80% | 47,094 psi | 80% | 2628 fps | 100% |
| Hodgdon H335 | <<locked>> | 80% | 47,964 psi | 82% | 2651 fps | 100% |
| Hodgdon H380 | <<locked>> | 86% | 40,132 psi | 68% | 2539 fps | 95.6% |
| Hodgdon H414 | <<locked>> | 98% | 48,182 psi | 82% | 2733 fps | 95.4% |
| Hodgdon H4895 | <<locked>> | 80% | 39,465 psi | 67% | 2520 fps | 97.9% |
| Hodgdon Hybrid 100V | <<locked>> | 90% | 31,546 psi | 54% | 2375 fps | 95% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 35,447 psi | 60% | 2484 fps | 97.3% |
| Hodgdon TrailBoss | <<locked>> | 80% | 25,759 psi | 44% | 1493 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 37,942 psi | 65% | 2474 fps | 97.4% |
| IMR 3031 | <<locked>> | 80% | 38,551 psi | 66% | 2526 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 34,940 psi | 59% | 2395 fps | 95.4% |
| IMR 4166 Enduron | <<locked>> | 88% | 48,631 psi | 83% | 2625 fps | 95.2% |
| IMR 4198 | <<locked>> | 80% | 48,863 psi | 83% | 2566 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 94% | 48,022 psi | 82% | 2644 fps | 95% |
| IMR 4831 | <<locked>> | 94% | 37,405 psi | 64% | 2526 fps | 95.5% |
| IMR 4895 | <<locked>> | 80% | 35,824 psi | 61% | 2470 fps | 96.4% |
| IMR 8208 XBR | <<locked>> | 80% | 41,249 psi | 70% | 2526 fps | 98.8% |
| Lovex D073.5 | <<locked>> | 80% | 46,151 psi | 79% | 2605 fps | 99.8% |
| Lovex D073.6 | <<locked>> | 80% | 37,449 psi | 64% | 2487 fps | 99.3% |
| Lovex S060 | <<locked>> | 80% | 39,842 psi | 68% | 2461 fps | 97.4% |
| Lovex S062 | <<locked>> | 80% | 34,548 psi | 59% | 2402 fps | 97.3% |
| Lovex S065 | <<locked>> | 94% | 43,961 psi | 75% | 2582 fps | 95.7% |
| Lovex S070 | <<locked>> | 98% | 47,094 psi | 80% | 2657 fps | 95.3% |
| Norma 201 | <<locked>> | 80% | 38,145 psi | 65% | 2464 fps | 98.2% |
| Norma 202 | <<locked>> | 80% | 38,537 psi | 66% | 2484 fps | 99.7% |
| Norma 203B | <<locked>> | 80% | 34,403 psi | 59% | 2428 fps | 95.8% |
| Norma URP | <<locked>> | 92% | 36,825 psi | 63% | 2520 fps | 95% |
| Ramshot Big Game | <<locked>> | 80% | 33,953 psi | 58% | 2434 fps | 95.3% |
| Ramshot Hunter | <<locked>> | 98% | 44,150 psi | 75% | 2667 fps | 95.2% |
| Ramshot TAC | <<locked>> | 80% | 41,104 psi | 70% | 2516 fps | 95% |
| Ramshot Wild Boar | <<locked>> | 80% | 40,292 psi | 69% | 2539 fps | 97.5% |
| Ramshot X-Terminator | <<locked>> | 80% | 44,788 psi | 76% | 2572 fps | 98.3% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 25,759 psi | 44% | 1526 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 46,528 psi | 79% | 2615 fps | 99.9% |
| ReloadSwiss RS 50 | <<locked>> | 90% | 46,731 psi | 80% | 2631 fps | 95.6% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 36,158 psi | 62% | 2526 fps | 95.7% |
| ReloadSwiss RS 60 | 46.2 gr | 80% | 29,762 psi | 51% | 2388 fps | 96.7% |
| ReloadSwiss RS 62 | <<locked>> | 94% | 38,696 psi | 66% | 2589 fps | 95.4% |
| ReloadSwiss RS 70 | <<locked>> | 96% | 42,525 psi | 72% | 2661 fps | 95.6% |
| Rottweil R 901 | <<locked>> | 80% | 41,901 psi | 71% | 2516 fps | 99.9% |
| Rottweil R 902 | <<locked>> | 80% | 36,274 psi | 62% | 2418 fps | 97.7% |
| Rottweil R 903 | <<locked>> | 82% | 31,763 psi | 54% | 2372 fps | 95.7% |
| Shooters World Long Rifle | <<locked>> | 94% | 43,961 psi | 75% | 2582 fps | 95.7% |
| Shooters World Match Rifle | <<locked>> | 80% | 37,449 psi | 64% | 2487 fps | 99.3% |
| Shooters World Precision | <<locked>> | 80% | 34,548 psi | 59% | 2402 fps | 97.3% |
| Shooters World SW4350 | <<locked>> | 98% | 47,094 psi | 80% | 2657 fps | 95.3% |
| Shooters World Tactical Rifle | <<locked>> | 80% | 49,197 psi | 84% | 2628 fps | 99.6% |
| SNPE Vectan SP 11 | <<locked>> | 82% | 33,243 psi | 57% | 2425 fps | 95.1% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 49,182 psi | 84% | 2618 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 39,030 psi | 66% | 2487 fps | 95.1% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 37,681 psi | 64% | 2477 fps | 96.8% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 40,016 psi | 68% | 2438 fps | 99.8% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 32,880 psi | 56% | 2306 fps | 99.5% |
| Somchem S321 | <<locked>> | 80% | 44,208 psi | 75% | 2598 fps | 99.4% |
| Somchem S335 | <<locked>> | 80% | 39,349 psi | 67% | 2438 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 38,754 psi | 66% | 2490 fps | 97% |
| Somchem S355 | <<locked>> | 82% | 32,895 psi | 56% | 2382 fps | 95.8% |
| Somchem S365 | <<locked>> | 88% | 28,572 psi | 49% | 2352 fps | 95.2% |
| Vihtavuori N130 | <<locked>> | 80% | 45,426 psi | 77% | 2510 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 40,234 psi | 68% | 2441 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 35,418 psi | 60% | 2415 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 36,318 psi | 62% | 2421 fps | 99.6% |
| Vihtavuori N150 | <<locked>> | 80% | 29,196 psi | 50% | 2274 fps | 95.9% |
| Vihtavuori N160 | <<locked>> | 92% | 38,624 psi | 66% | 2523 fps | 95.5% |
| Vihtavuori N530 | <<locked>> | 80% | 41,249 psi | 70% | 2523 fps | 98.8% |
| Vihtavuori N540 | <<locked>> | 80% | 34,809 psi | 59% | 2405 fps | 99.1% |
| Vihtavuori N550 | <<locked>> | 92% | 37,753 psi | 64% | 2523 fps | 95% |
| Winchester 6.5 StaBALL | <<locked>> | 86% | 32,097 psi | 55% | 2349 fps | 95.3% |
| Winchester 748 | <<locked>> | 80% | 40,161 psi | 68% | 2556 fps | 99.2% |
| Winchester 760 | <<locked>> | 98% | 48,414 psi | 82% | 2740 fps | 95.4% |
| Winchester StaBALL Match | <<locked>> | 80% | 36,956 psi | 63% | 2480 fps | 97.3% |
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 107 powders for .30-06 Spring. loaded with the .308 | 166gr | Hammer Stone Hammer. ReloadSwiss RS 60 delivers the highest muzzle velocity at 2,848 fps; across all powders the maximum-charge window runs from 1,670 fps to 2,848 fps. Accurate 3100 gives the best case fill at 100 %, and 107 of the 107 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (405 MPa), the top charges use 50–90 %, leaving at least 10 % headroom. The 166.0 gr projectile in 0.308" calls for a 1:12.5 twist; slower twists will usually not stabilise this weight. Accurate 3100, Accurate 4350, Alliant Reloder-16 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. ReloadSwiss RS 60, Alliant Power Pro 2000-MR, Alliant Reloder-17 rank at the top here: for .30-06 Spring. with the .308 | 166gr | Hammer Stone Hammer they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Accurate 3100, Alliant Reloder-26, Hodgdon H4350 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.