Load Specifications
Load data in caliber 9.5 x 66 SE v. Hofe with .375 | 270gr | Impala RNFP KO bullet and 99 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Power Pro 2000-MR, Hodgdon Superformance 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.
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You can find more information in our FAQ: How can I use the Personalized Load Calculator?
Max Load - Barrel Length: 25.6"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 84% | 57,072 psi | 89% | 2595 fps | 100% |
| Accurate 2495 | <<locked>> | 88% | 56,637 psi | 89% | 2628 fps | 100% |
| Accurate 2520 | <<locked>> | 84% | 57,363 psi | 90% | 2684 fps | 100% |
| Accurate 2700 | <<locked>> | 90% | 57,667 psi | 90% | 2664 fps | 97.7% |
| Accurate 3100ᴾ | <<locked>> | 100% | 42,786 psi | 67% | 2539 fps | 96.7% |
| Accurate 4064 | <<locked>> | 90% | 56,246 psi | 88% | 2674 fps | 100% |
| Accurate 4350 | <<locked>> | 98% | 55,056 psi | 86% | 2753 fps | 99.8% |
| ADI AR 2206H | <<locked>> | 86% | 55,622 psi | 87% | 2694 fps | 100% |
| ADI AR 2208 | <<locked>> | 92% | 56,275 psi | 88% | 2690 fps | 99.9% |
| ADI Benchmark 8208 | <<locked>> | 84% | 54,418 psi | 85% | 2644 fps | 100% |
| Alliant AR-Comp | <<locked>> | 84% | 55,434 psi | 87% | 2618 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 88% | 54,578 psi | 86% | 2802 fps | 99.9% |
| Alliant Reloder- TS 15.5 | <<locked>> | 92% | 56,391 psi | 88% | 2713 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 90% | 57,014 psi | 89% | 2733 fps | 100% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 55,492 psi | 87% | 2792 fps | 99.9% |
| Alliant Reloder-17 | <<locked>> | 96% | 56,898 psi | 89% | 2831 fps | 100% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 40,625 psi | 64% | 2566 fps | 99.3% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 44,991 psi | 71% | 2713 fps | 98.6% |
| Baschieri & Pellagri 107 | <<locked>> | 86% | 54,897 psi | 86% | 2707 fps | 99.8% |
| Bofors RP3 | <<locked>> | 92% | 57,551 psi | 90% | 2733 fps | 100% |
| Bofors RP7 | <<locked>> | 96% | 57,203 psi | 90% | 2700 fps | 97.9% |
| Hodgdon Benchmark | <<locked>> | 84% | 56,130 psi | 88% | 2625 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 86% | 57,580 psi | 90% | 2726 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 82% | 55,317 psi | 87% | 2766 fps | 100% |
| Hodgdon H380 | <<locked>> | 90% | 54,665 psi | 86% | 2697 fps | 99.5% |
| Hodgdon H414 | <<locked>> | 98% | 57,217 psi | 90% | 2792 fps | 98.5% |
| Hodgdon H4350 | <<locked>> | 94% | 54,331 psi | 85% | 2700 fps | 96.8% |
| Hodgdon H4895 | <<locked>> | 86% | 56,130 psi | 88% | 2703 fps | 100% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 51,895 psi | 81% | 2677 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 88% | 55,100 psi | 86% | 2733 fps | 100% |
| Hodgdon Superformance | <<locked>> | 96% | 54,215 psi | 85% | 2772 fps | 97.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,984 psi | 56% | 1621 fps | 100% |
| Hodgdon VARGET | <<locked>> | 88% | 56,971 psi | 89% | 2700 fps | 100% |
| IMR 3031 | <<locked>> | 86% | 56,086 psi | 88% | 2684 fps | 100% |
| IMR 4064 | <<locked>> | 90% | 55,912 psi | 88% | 2674 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 88% | 55,738 psi | 87% | 2654 fps | 98.1% |
| IMR 4350ᴾ | <<locked>> | 100% | 57,000 psi | 89% | 2723 fps | 97.9% |
| IMR 4451 Enduron | <<locked>> | 94% | 55,361 psi | 87% | 2677 fps | 98% |
| IMR 4831ᴾ | <<locked>> | 100% | 55,216 psi | 87% | 2740 fps | 99.8% |
| IMR 4895 | <<locked>> | 88% | 55,056 psi | 86% | 2717 fps | 100% |
| IMR 8208 XBR | <<locked>> | 84% | 54,418 psi | 85% | 2644 fps | 100% |
| Lovex D073.6 | <<locked>> | 86% | 55,666 psi | 87% | 2674 fps | 100% |
| Lovex S060 | <<locked>> | 86% | 55,013 psi | 86% | 2621 fps | 100% |
| Lovex S062 | <<locked>> | 90% | 56,057 psi | 88% | 2674 fps | 100% |
| Lovex S065 | <<locked>> | 96% | 55,143 psi | 86% | 2677 fps | 99% |
| Lovex S070 | <<locked>> | 98% | 55,999 psi | 88% | 2710 fps | 98.4% |
| Norma 201 | <<locked>> | 86% | 54,766 psi | 86% | 2644 fps | 100% |
| Norma 202 | <<locked>> | 86% | 54,911 psi | 86% | 2641 fps | 100% |
| Norma 203B | <<locked>> | 90% | 56,202 psi | 88% | 2723 fps | 100% |
| Norma 204ᴾ | <<locked>> | 100% | 57,725 psi | 90% | 2772 fps | 96.8% |
| Norma MRPᴾ | <<locked>> | 100% | 44,918 psi | 70% | 2671 fps | 95.9% |
| Norma URPᴾ | <<locked>> | 100% | 56,985 psi | 89% | 2779 fps | 99.8% |
| Ramshot Big Game | <<locked>> | 90% | 56,391 psi | 88% | 2743 fps | 100% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 55,666 psi | 87% | 2779 fps | 99% |
| Ramshot TAC | <<locked>> | 84% | 54,607 psi | 86% | 2664 fps | 99.1% |
| Ramshot Wild Boar | <<locked>> | 84% | 54,143 psi | 85% | 2680 fps | 100% |
| Ramshot X-Terminator | <<locked>> | 82% | 55,245 psi | 87% | 2644 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,521 psi | 57% | 1660 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 82% | 57,246 psi | 90% | 2667 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 90% | 54,781 psi | 86% | 2677 fps | 98.5% |
| ReloadSwiss RS 52 | <<locked>> | 88% | 57,348 psi | 90% | 2799 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 94% | 56,695 psi | 89% | 2828 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 98% | 54,099 psi | 85% | 2769 fps | 99.6% |
| ReloadSwiss RS 70ᴾ | <<locked>> | 100% | 57,188 psi | 90% | 2841 fps | 99.7% |
| Rottweil R 901 | <<locked>> | 84% | 56,391 psi | 88% | 2628 fps | 100% |
| Rottweil R 902 | <<locked>> | 88% | 55,303 psi | 87% | 2641 fps | 100% |
| Rottweil R 903 | <<locked>> | 94% | 57,435 psi | 90% | 2726 fps | 100% |
| Rottweil R 907 | <<locked>> | 96% | 57,203 psi | 90% | 2700 fps | 97.9% |
| Shooters World Long Rifle | <<locked>> | 96% | 55,143 psi | 86% | 2677 fps | 99% |
| Shooters World Match Rifle | <<locked>> | 86% | 55,666 psi | 87% | 2674 fps | 100% |
| Shooters World Precision | <<locked>> | 90% | 56,057 psi | 88% | 2674 fps | 100% |
| Shooters World SW4350 | <<locked>> | 98% | 55,999 psi | 88% | 2710 fps | 98.4% |
| SNPE Vectan SP 11 | <<locked>> | 92% | 54,853 psi | 86% | 2730 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 86% | 56,942 psi | 89% | 2697 fps | 99.6% |
| SNPE Vectan SP 9 | <<locked>> | 88% | 57,058 psi | 89% | 2710 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 86% | 55,956 psi | 88% | 2579 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 92% | 55,811 psi | 87% | 2579 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 96% | 55,347 psi | 87% | 2631 fps | 98% |
| Somchem S321 | <<locked>> | 82% | 55,767 psi | 87% | 2677 fps | 100% |
| Somchem S335 | <<locked>> | 86% | 55,361 psi | 87% | 2579 fps | 100% |
| Somchem S341 | <<locked>> | 86% | 56,086 psi | 88% | 2684 fps | 100% |
| Somchem S355 | <<locked>> | 94% | 57,334 psi | 90% | 2720 fps | 100% |
| Somchem S365ᴾ | <<locked>> | 100% | 51,547 psi | 81% | 2740 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 48,341 psi | 76% | 2628 fps | 96.3% |
| Vihtavuori N130 | <<locked>> | 82% | 55,709 psi | 87% | 2543 fps | 100% |
| Vihtavuori N133 | <<locked>> | 86% | 56,014 psi | 88% | 2562 fps | 100% |
| Vihtavuori N135 | <<locked>> | 88% | 54,839 psi | 86% | 2605 fps | 100% |
| Vihtavuori N140 | <<locked>> | 88% | 55,201 psi | 87% | 2621 fps | 100% |
| Vihtavuori N150 | <<locked>> | 94% | 55,288 psi | 87% | 2651 fps | 100% |
| Vihtavuori N160 | <<locked>> | 98% | 56,043 psi | 88% | 2726 fps | 99.7% |
| Vihtavuori N530 | <<locked>> | 84% | 54,940 psi | 86% | 2644 fps | 100% |
| Vihtavuori N540 | <<locked>> | 90% | 56,811 psi | 89% | 2664 fps | 100% |
| Vihtavuori N550 | <<locked>> | 98% | 55,187 psi | 86% | 2736 fps | 99.6% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 44,454 psi | 70% | 2638 fps | 99.2% |
| Winchester 6.5 StaBALL | <<locked>> | 98% | 56,246 psi | 88% | 2707 fps | 100% |
| Winchester 748 | <<locked>> | 84% | 54,592 psi | 86% | 2687 fps | 100% |
| Winchester 760 | <<locked>> | 98% | 57,217 psi | 90% | 2792 fps | 98.5% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 36,724 psi | 58% | 2582 fps | 99.4% |
| Winchester StaBALL Match | <<locked>> | 88% | 57,087 psi | 89% | 2720 fps | 100% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 25.6"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 80% | 50,618 psi | 79% | 2510 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 44,686 psi | 70% | 2464 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 50,328 psi | 79% | 2592 fps | 100% |
| Accurate 2700 | <<locked>> | 82% | 45,107 psi | 71% | 2467 fps | 95.1% |
| Accurate 3100 | <<locked>> | 96% | 37,695 psi | 59% | 2444 fps | 95.2% |
| Accurate 4064 | <<locked>> | 80% | 42,206 psi | 66% | 2464 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 33,054 psi | 52% | 2356 fps | 95.7% |
| ADI AR 2206H | <<locked>> | 80% | 46,528 psi | 73% | 2552 fps | 99.6% |
| ADI AR 2208 | <<locked>> | 80% | 39,711 psi | 62% | 2415 fps | 98.1% |
| ADI Benchmark 8208 | <<locked>> | 80% | 48,414 psi | 76% | 2552 fps | 100% |
| Alliant AR-Comp | <<locked>> | 80% | 49,023 psi | 77% | 2539 fps | 100% |
| Alliant Power Pro 2000-MR | 69.5 gr | 80% | 42,148 psi | 66% | 2585 fps | 98.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 39,639 psi | 62% | 2441 fps | 99.2% |
| Alliant Reloder-15 | <<locked>> | 80% | 42,453 psi | 67% | 2500 fps | 98.8% |
| Alliant Reloder-16 | <<locked>> | 82% | 33,040 psi | 52% | 2356 fps | 95.5% |
| Alliant Reloder-17 | 68.5 gr | 80% | 34,403 psi | 54% | 2421 fps | 97.9% |
| Alliant Reloder-23 | <<locked>> | 88% | 29,022 psi | 45% | 2280 fps | 95.4% |
| Alliant Reloder-26 | <<locked>> | 92% | 34,896 psi | 55% | 2490 fps | 95.4% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 45,397 psi | 71% | 2556 fps | 98.8% |
| Bofors RP3 | <<locked>> | 80% | 39,769 psi | 62% | 2454 fps | 99.3% |
| Bofors RP7 | <<locked>> | 88% | 45,295 psi | 71% | 2510 fps | 95.5% |
| Hodgdon Benchmark | <<locked>> | 80% | 50,024 psi | 78% | 2539 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 47,485 psi | 74% | 2582 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 80% | 51,866 psi | 81% | 2713 fps | 99.8% |
| Hodgdon H380 | <<locked>> | 80% | 40,263 psi | 63% | 2451 fps | 97.2% |
| Hodgdon H414 | <<locked>> | 88% | 41,916 psi | 66% | 2539 fps | 95.4% |
| Hodgdon H4350 | <<locked>> | 90% | 48,211 psi | 76% | 2602 fps | 95.5% |
| Hodgdon H4895 | <<locked>> | 80% | 47,007 psi | 74% | 2566 fps | 99.8% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 28,950 psi | 45% | 2221 fps | 95.7% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 42,815 psi | 67% | 2543 fps | 99.7% |
| Hodgdon Superformance | 81.4 gr | 90% | 44,266 psi | 69% | 2602 fps | 95.3% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,963 psi | 42% | 1450 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 44,889 psi | 70% | 2516 fps | 99.6% |
| IMR 3031 | <<locked>> | 80% | 46,731 psi | 73% | 2556 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 41,713 psi | 65% | 2444 fps | 98.7% |
| IMR 4166 Enduron | <<locked>> | 80% | 43,976 psi | 69% | 2461 fps | 95.8% |
| IMR 4350 | <<locked>> | 92% | 45,005 psi | 71% | 2533 fps | 95.5% |
| IMR 4451 Enduron | <<locked>> | 86% | 43,845 psi | 69% | 2490 fps | 95.6% |
| IMR 4831 | <<locked>> | 82% | 32,039 psi | 50% | 2316 fps | 95.3% |
| IMR 4895 | <<locked>> | 80% | 43,410 psi | 68% | 2530 fps | 99.3% |
| IMR 8208 XBR | <<locked>> | 80% | 48,414 psi | 76% | 2552 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 46,224 psi | 72% | 2539 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 46,253 psi | 72% | 2487 fps | 99.5% |
| Lovex S062 | <<locked>> | 80% | 42,047 psi | 66% | 2454 fps | 99.7% |
| Lovex S065 | <<locked>> | 82% | 37,101 psi | 58% | 2359 fps | 95.3% |
| Lovex S070 | <<locked>> | 88% | 41,814 psi | 66% | 2477 fps | 95.5% |
| Norma 201 | <<locked>> | 80% | 46,166 psi | 72% | 2513 fps | 99.9% |
| Norma 202 | <<locked>> | 80% | 46,035 psi | 72% | 2513 fps | 100% |
| Norma 203B | <<locked>> | 80% | 41,858 psi | 66% | 2490 fps | 99% |
| Norma 204 | <<locked>> | 96% | 50,734 psi | 80% | 2667 fps | 95.4% |
| Norma MRP | <<locked>> | 98% | 42,264 psi | 66% | 2615 fps | 95.1% |
| Norma URP | <<locked>> | 82% | 33,098 psi | 52% | 2349 fps | 95.4% |
| Ramshot Big Game | <<locked>> | 80% | 41,002 psi | 64% | 2500 fps | 98.8% |
| Ramshot Hunter | <<locked>> | 88% | 38,624 psi | 61% | 2477 fps | 95.3% |
| Ramshot TAC | <<locked>> | 80% | 48,225 psi | 76% | 2562 fps | 98.2% |
| Ramshot Wild Boar | <<locked>> | 80% | 47,674 psi | 75% | 2582 fps | 99.7% |
| Ramshot X-Terminator | <<locked>> | 80% | 51,996 psi | 81% | 2598 fps | 99.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,369 psi | 43% | 1483 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 53,954 psi | 85% | 2625 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 40,408 psi | 63% | 2428 fps | 95.5% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 44,251 psi | 69% | 2595 fps | 99.1% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 36,419 psi | 57% | 2480 fps | 99.9% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 34,606 psi | 54% | 2415 fps | 95.8% |
| ReloadSwiss RS 70 | <<locked>> | 86% | 36,840 psi | 58% | 2467 fps | 95.6% |
| Rottweil R 901 | <<locked>> | 80% | 50,415 psi | 79% | 2543 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 43,961 psi | 69% | 2467 fps | 99.8% |
| Rottweil R 903 | <<locked>> | 80% | 37,637 psi | 59% | 2405 fps | 98.8% |
| Rottweil R 907 | <<locked>> | 88% | 45,295 psi | 71% | 2510 fps | 95.5% |
| Shooters World Long Rifle | <<locked>> | 82% | 37,101 psi | 58% | 2359 fps | 95.3% |
| Shooters World Match Rifle | <<locked>> | 80% | 46,224 psi | 72% | 2539 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 42,047 psi | 66% | 2454 fps | 99.7% |
| Shooters World SW4350 | <<locked>> | 88% | 41,814 psi | 66% | 2477 fps | 95.5% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 37,840 psi | 59% | 2441 fps | 98.2% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 46,891 psi | 73% | 2543 fps | 98.4% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 44,889 psi | 70% | 2526 fps | 99.4% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 46,876 psi | 73% | 2454 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 39,291 psi | 62% | 2336 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 43,424 psi | 68% | 2444 fps | 95.7% |
| Somchem S321 | <<locked>> | 80% | 52,243 psi | 82% | 2628 fps | 100% |
| Somchem S335 | <<locked>> | 80% | 46,804 psi | 73% | 2461 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 46,238 psi | 72% | 2536 fps | 99.5% |
| Somchem S355 | <<locked>> | 80% | 38,232 psi | 60% | 2405 fps | 98.7% |
| Somchem S365 | <<locked>> | 80% | 28,268 psi | 44% | 2264 fps | 97.1% |
| Somchem S385 | <<locked>> | 98% | 45,397 psi | 71% | 2579 fps | 95.6% |
| Vihtavuori N130 | <<locked>> | 80% | 52,533 psi | 82% | 2500 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 47,036 psi | 74% | 2444 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 43,279 psi | 68% | 2444 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 43,613 psi | 68% | 2451 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 36,289 psi | 57% | 2343 fps | 99.3% |
| Vihtavuori N160 | <<locked>> | 80% | 32,416 psi | 51% | 2300 fps | 95% |
| Vihtavuori N530 | <<locked>> | 80% | 48,588 psi | 76% | 2552 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 42,105 psi | 66% | 2448 fps | 100% |
| Vihtavuori N550 | <<locked>> | 82% | 34,026 psi | 53% | 2356 fps | 95.5% |
| Vihtavuori N555 | <<locked>> | 88% | 31,111 psi | 49% | 2356 fps | 95.6% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 32,068 psi | 50% | 2274 fps | 97.2% |
| Winchester 748 | <<locked>> | 80% | 48,138 psi | 75% | 2595 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 42,090 psi | 66% | 2543 fps | 95.5% |
| Winchester StaBALL HD | <<locked>> | 92% | 29,095 psi | 46% | 2356 fps | 95.9% |
| Winchester StaBALL Match | <<locked>> | 80% | 44,382 psi | 70% | 2530 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 99 powders for 9.5 x 66 SE v. Hofe loaded with the .375 | 270gr | Impala RNFP KO. ReloadSwiss RS 70 delivers the highest muzzle velocity at 2,841 fps; across all powders the maximum-charge window runs from 1,621 fps to 2,841 fps. Accurate 3100 gives the best case fill at 100 %, and 99 of the 99 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 56–90 %, leaving at least 10 % headroom. The 270.0 gr projectile in 0.375" calls for a 1:6.0 twist; slower twists will usually not stabilise this weight. Accurate 3100, Alliant Reloder-16, Alliant Reloder-23 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 Power Pro 2000-MR, Hodgdon Superformance, Alliant Reloder-17 rank at the top here: for 9.5 x 66 SE v. Hofe with the .375 | 270gr | Impala RNFP KO 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.