Load Specifications
Load data in caliber .375 Ruger with .375 | 270gr | Impala RNFP KO bullet and 97 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 Reloder-17 and Alliant Power Pro 2000-MR.
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: 23"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 84% | 54,317 psi | 88% | 2438 fps | 100% |
| Accurate 2495 | <<locked>> | 88% | 53,548 psi | 86% | 2464 fps | 100% |
| Accurate 2520 | <<locked>> | 84% | 54,230 psi | 87% | 2510 fps | 100% |
| Accurate 2700 | <<locked>> | 90% | 55,143 psi | 89% | 2484 fps | 96.2% |
| Accurate 4064 | <<locked>> | 90% | 53,258 psi | 86% | 2503 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 55,172 psi | 89% | 2605 fps | 99.3% |
| ADI AR 2206H | <<locked>> | 88% | 56,144 psi | 90% | 2562 fps | 99.9% |
| ADI AR 2208 | <<locked>> | 92% | 53,635 psi | 86% | 2513 fps | 99.4% |
| ADI Benchmark 8208 | <<locked>> | 86% | 55,201 psi | 89% | 2520 fps | 100% |
| Alliant AR-Comp | <<locked>> | 86% | 55,854 psi | 90% | 2500 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 90% | 55,172 psi | 89% | 2661 fps | 99.7% |
| Alliant Reloder- TS 15.5 | <<locked>> | 92% | 53,635 psi | 86% | 2536 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 90% | 54,186 psi | 87% | 2552 fps | 99.6% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 52,663 psi | 85% | 2602 fps | 99.3% |
| Alliant Reloder-17 | <<locked>> | 96% | 53,693 psi | 86% | 2638 fps | 100% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 38,406 psi | 62% | 2375 fps | 97.9% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 42,293 psi | 68% | 2500 fps | 96.7% |
| Baschieri & Pellagri 107 | <<locked>> | 88% | 55,695 psi | 90% | 2572 fps | 99.4% |
| Bofors RP3 | <<locked>> | 92% | 54,476 psi | 88% | 2552 fps | 100% |
| Bofors RP7 | <<locked>> | 96% | 54,462 psi | 88% | 2513 fps | 96.4% |
| Hodgdon Benchmark | <<locked>> | 84% | 53,751 psi | 87% | 2461 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 86% | 54,491 psi | 88% | 2546 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 84% | 55,912 psi | 90% | 2631 fps | 99.7% |
| Hodgdon H322 | <<locked>> | 82% | 55,695 psi | 90% | 2513 fps | 100% |
| Hodgdon H380 | <<locked>> | 92% | 55,245 psi | 89% | 2559 fps | 99% |
| Hodgdon H414 | <<locked>> | 98% | 54,012 psi | 87% | 2595 fps | 97.1% |
| Hodgdon H4350 | <<locked>> | 96% | 54,853 psi | 88% | 2556 fps | 95.8% |
| Hodgdon H4895 | <<locked>> | 86% | 53,432 psi | 86% | 2530 fps | 99.9% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 48,979 psi | 79% | 2493 fps | 99.6% |
| Hodgdon LEVERevolution | <<locked>> | 90% | 55,477 psi | 89% | 2595 fps | 100% |
| Hodgdon Superformance | <<locked>> | 98% | 54,897 psi | 88% | 2621 fps | 96.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,752 psi | 58% | 1545 fps | 100% |
| Hodgdon VARGET | <<locked>> | 88% | 54,317 psi | 88% | 2526 fps | 99.9% |
| IMR 3031 | <<locked>> | 86% | 53,026 psi | 85% | 2516 fps | 100% |
| IMR 4064 | <<locked>> | 90% | 53,185 psi | 86% | 2497 fps | 99.5% |
| IMR 4166 Enduron | <<locked>> | 88% | 53,287 psi | 86% | 2474 fps | 96.8% |
| IMR 4350ᴾ | <<locked>> | 100% | 54,143 psi | 87% | 2533 fps | 96.4% |
| IMR 4451 Enduron | <<locked>> | 96% | 56,043 psi | 90% | 2543 fps | 97.2% |
| IMR 4831ᴾ | <<locked>> | 100% | 51,982 psi | 84% | 2546 fps | 99.1% |
| IMR 4895 | <<locked>> | 90% | 55,521 psi | 89% | 2582 fps | 99.9% |
| IMR 8208 XBR | <<locked>> | 86% | 55,201 psi | 89% | 2520 fps | 100% |
| Lovex D073.5 | <<locked>> | 82% | 56,130 psi | 90% | 2513 fps | 100% |
| Lovex D073.6 | <<locked>> | 88% | 56,130 psi | 90% | 2543 fps | 100% |
| Lovex S060 | <<locked>> | 88% | 55,767 psi | 90% | 2497 fps | 99.8% |
| Lovex S062 | <<locked>> | 90% | 53,505 psi | 86% | 2503 fps | 100% |
| Lovex S065 | <<locked>> | 98% | 55,521 psi | 89% | 2536 fps | 98.4% |
| Lovex S070 | <<locked>> | 98% | 53,055 psi | 85% | 2523 fps | 97% |
| Norma 201 | <<locked>> | 88% | 55,317 psi | 89% | 2516 fps | 100% |
| Norma 202 | <<locked>> | 88% | 55,463 psi | 89% | 2516 fps | 100% |
| Norma 203B | <<locked>> | 90% | 53,476 psi | 86% | 2543 fps | 99.7% |
| Norma URPᴾ | <<locked>> | 100% | 53,606 psi | 86% | 2589 fps | 99.1% |
| Ramshot Big Game | <<locked>> | 90% | 53,374 psi | 86% | 2559 fps | 99.7% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 52,576 psi | 85% | 2579 fps | 97.7% |
| Ramshot TAC | <<locked>> | 86% | 55,492 psi | 89% | 2533 fps | 98.5% |
| Ramshot Wild Boar | <<locked>> | 86% | 54,853 psi | 88% | 2549 fps | 99.8% |
| Ramshot X-Terminator | <<locked>> | 82% | 52,750 psi | 85% | 2474 fps | 99.6% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,289 psi | 58% | 1581 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 82% | 54,708 psi | 88% | 2503 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 92% | 55,390 psi | 89% | 2536 fps | 97.8% |
| ReloadSwiss RS 52 | <<locked>> | 88% | 54,215 psi | 87% | 2612 fps | 99.6% |
| ReloadSwiss RS 60 | <<locked>> | 94% | 53,432 psi | 86% | 2638 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 54,143 psi | 87% | 2618 fps | 99.1% |
| ReloadSwiss RS 70ᴾ | <<locked>> | 100% | 54,273 psi | 87% | 2638 fps | 98.8% |
| Rottweil R 901 | <<locked>> | 84% | 53,867 psi | 87% | 2467 fps | 100% |
| Rottweil R 902 | <<locked>> | 90% | 55,956 psi | 90% | 2516 fps | 100% |
| Rottweil R 903 | <<locked>> | 94% | 54,302 psi | 87% | 2546 fps | 100% |
| Rottweil R 907 | <<locked>> | 96% | 54,462 psi | 88% | 2513 fps | 96.4% |
| Shooters World Long Rifle | <<locked>> | 98% | 55,521 psi | 89% | 2536 fps | 98.4% |
| Shooters World Match Rifle | <<locked>> | 88% | 56,130 psi | 90% | 2543 fps | 100% |
| Shooters World Precision | <<locked>> | 90% | 53,505 psi | 86% | 2503 fps | 100% |
| Shooters World SW4350 | <<locked>> | 98% | 53,055 psi | 85% | 2523 fps | 97% |
| SNPE Vectan SP 11 | <<locked>> | 94% | 55,143 psi | 89% | 2589 fps | 99.8% |
| SNPE Vectan SP 7 | <<locked>> | 86% | 54,070 psi | 87% | 2513 fps | 98.7% |
| SNPE Vectan SP 9 | <<locked>> | 88% | 54,520 psi | 88% | 2536 fps | 99.8% |
| SNPE Vectan Tubal 3000 | <<locked>> | 86% | 53,577 psi | 86% | 2421 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 92% | 53,156 psi | 86% | 2418 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 98% | 56,014 psi | 90% | 2493 fps | 97.2% |
| Somchem S321 | <<locked>> | 82% | 53,113 psi | 86% | 2507 fps | 100% |
| Somchem S335 | <<locked>> | 88% | 55,999 psi | 90% | 2457 fps | 100% |
| Somchem S341 | <<locked>> | 86% | 53,243 psi | 86% | 2503 fps | 99.7% |
| Somchem S355 | <<locked>> | 94% | 54,563 psi | 88% | 2543 fps | 99.9% |
| Somchem S365ᴾ | <<locked>> | 100% | 48,457 psi | 78% | 2549 fps | 100% |
| Vihtavuori N130 | <<locked>> | 82% | 53,345 psi | 86% | 2392 fps | 100% |
| Vihtavuori N133 | <<locked>> | 86% | 53,563 psi | 86% | 2411 fps | 100% |
| Vihtavuori N135 | <<locked>> | 90% | 55,071 psi | 89% | 2484 fps | 100% |
| Vihtavuori N140 | <<locked>> | 90% | 55,883 psi | 90% | 2497 fps | 100% |
| Vihtavuori N150 | <<locked>> | 96% | 55,811 psi | 90% | 2523 fps | 100% |
| Vihtavuori N160 | <<locked>> | 98% | 52,968 psi | 85% | 2539 fps | 99% |
| Vihtavuori N530 | <<locked>> | 86% | 55,724 psi | 90% | 2520 fps | 100% |
| Vihtavuori N540 | <<locked>> | 90% | 54,157 psi | 87% | 2497 fps | 100% |
| Vihtavuori N550ᴾ | <<locked>> | 100% | 55,405 psi | 89% | 2592 fps | 99.2% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 41,553 psi | 67% | 2444 fps | 97.9% |
| Winchester 6.5 StaBALL | <<locked>> | 98% | 53,316 psi | 86% | 2520 fps | 99.9% |
| Winchester 748 | <<locked>> | 86% | 55,245 psi | 89% | 2559 fps | 100% |
| Winchester 760 | <<locked>> | 98% | 54,215 psi | 87% | 2595 fps | 97.2% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 34,635 psi | 56% | 2365 fps | 97.3% |
| Winchester StaBALL Match | <<locked>> | 88% | 54,186 psi | 87% | 2543 fps | 99.9% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 23"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 80% | 48,312 psi | 78% | 2359 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 42,119 psi | 68% | 2306 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 47,645 psi | 77% | 2421 fps | 100% |
| Accurate 2700 | <<locked>> | 88% | 51,808 psi | 83% | 2438 fps | 95.5% |
| Accurate 4064 | <<locked>> | 80% | 39,740 psi | 64% | 2300 fps | 100% |
| Accurate 4350 | <<locked>> | 86% | 35,143 psi | 57% | 2277 fps | 95.1% |
| ADI AR 2206H | <<locked>> | 80% | 44,411 psi | 72% | 2385 fps | 98.7% |
| ADI AR 2208 | <<locked>> | 80% | 37,869 psi | 61% | 2251 fps | 96.6% |
| ADI Benchmark 8208 | <<locked>> | 80% | 46,224 psi | 74% | 2388 fps | 99.6% |
| Alliant AR-Comp | <<locked>> | 80% | 46,282 psi | 75% | 2382 fps | 100% |
| Alliant Power Pro 2000-MR | 64.4 gr | 80% | 40,045 psi | 65% | 2402 fps | 97% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 37,666 psi | 61% | 2277 fps | 98.2% |
| Alliant Reloder-15 | <<locked>> | 80% | 40,306 psi | 65% | 2329 fps | 97.5% |
| Alliant Reloder-16 | <<locked>> | 88% | 37,275 psi | 60% | 2323 fps | 95.8% |
| Alliant Reloder-17 | 63.4 gr | 80% | 32,605 psi | 53% | 2241 fps | 95.9% |
| Alliant Reloder-23 | <<locked>> | 94% | 32,489 psi | 52% | 2241 fps | 95.6% |
| Alliant Reloder-26 | <<locked>> | 98% | 39,711 psi | 64% | 2448 fps | 95.8% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 43,062 psi | 69% | 2379 fps | 97.6% |
| Bofors RP3 | <<locked>> | 80% | 37,507 psi | 60% | 2283 fps | 98.2% |
| Bofors RP7 | <<locked>> | 92% | 48,356 psi | 78% | 2425 fps | 95% |
| Hodgdon Benchmark | <<locked>> | 80% | 47,848 psi | 77% | 2375 fps | 99.9% |
| Hodgdon BL-C2 | <<locked>> | 80% | 45,063 psi | 73% | 2411 fps | 99.8% |
| Hodgdon CFE223 | <<locked>> | 80% | 48,878 psi | 79% | 2530 fps | 99.1% |
| Hodgdon H322 | <<locked>> | 80% | 52,359 psi | 84% | 2470 fps | 100% |
| Hodgdon H380 | <<locked>> | 80% | 38,232 psi | 62% | 2280 fps | 95.5% |
| Hodgdon H414 | <<locked>> | 94% | 47,674 psi | 77% | 2497 fps | 95.7% |
| Hodgdon H4350 | <<locked>> | 94% | 51,677 psi | 83% | 2510 fps | 95.1% |
| Hodgdon H4895 | <<locked>> | 80% | 44,744 psi | 72% | 2395 fps | 99.1% |
| Hodgdon Hybrid 100V | <<locked>> | 84% | 30,719 psi | 49% | 2146 fps | 95.2% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 40,379 psi | 65% | 2365 fps | 98.8% |
| Hodgdon Superformance | <<locked>> | 96% | 51,198 psi | 82% | 2566 fps | 95.8% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,774 psi | 43% | 1381 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 42,801 psi | 69% | 2349 fps | 98.8% |
| IMR 3031 | <<locked>> | 80% | 44,106 psi | 71% | 2392 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 39,740 psi | 64% | 2280 fps | 97.4% |
| IMR 4166 Enduron | <<locked>> | 84% | 47,384 psi | 76% | 2385 fps | 95.4% |
| IMR 4350 | <<locked>> | 96% | 47,877 psi | 77% | 2438 fps | 95% |
| IMR 4451 Enduron | <<locked>> | 90% | 47,050 psi | 76% | 2408 fps | 95.3% |
| IMR 4831 | <<locked>> | 88% | 36,056 psi | 58% | 2280 fps | 95.5% |
| IMR 4895 | <<locked>> | 80% | 41,176 psi | 66% | 2356 fps | 98.2% |
| IMR 8208 XBR | <<locked>> | 80% | 46,224 psi | 74% | 2388 fps | 99.6% |
| Lovex D073.5 | <<locked>> | 80% | 52,663 psi | 85% | 2467 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 43,671 psi | 70% | 2372 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 44,266 psi | 71% | 2326 fps | 98.7% |
| Lovex S062 | <<locked>> | 80% | 39,943 psi | 64% | 2290 fps | 98.9% |
| Lovex S065 | <<locked>> | 88% | 41,669 psi | 67% | 2323 fps | 95.5% |
| Lovex S070 | <<locked>> | 92% | 44,657 psi | 72% | 2388 fps | 95.1% |
| Norma 201 | <<locked>> | 80% | 43,845 psi | 71% | 2346 fps | 99.4% |
| Norma 202 | <<locked>> | 80% | 43,816 psi | 71% | 2356 fps | 100% |
| Norma 203B | <<locked>> | 80% | 39,711 psi | 64% | 2320 fps | 97.8% |
| Norma URP | <<locked>> | 88% | 37,362 psi | 60% | 2316 fps | 95.7% |
| Ramshot Big Game | <<locked>> | 80% | 38,827 psi | 63% | 2326 fps | 97.4% |
| Ramshot Hunter | <<locked>> | 94% | 43,743 psi | 70% | 2438 fps | 95.6% |
| Ramshot TAC | <<locked>> | 80% | 46,050 psi | 74% | 2388 fps | 96.9% |
| Ramshot Wild Boar | <<locked>> | 80% | 45,440 psi | 73% | 2408 fps | 98.9% |
| Ramshot X-Terminator | <<locked>> | 80% | 49,588 psi | 80% | 2428 fps | 99.3% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,180 psi | 44% | 1414 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 51,372 psi | 83% | 2457 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 43,337 psi | 70% | 2352 fps | 95.1% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 41,597 psi | 67% | 2411 fps | 97.8% |
| ReloadSwiss RS 60 | 63.4 gr | 80% | 34,505 psi | 56% | 2300 fps | 98.9% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 36,883 psi | 59% | 2329 fps | 95.3% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 39,349 psi | 63% | 2375 fps | 95% |
| Rottweil R 901 | <<locked>> | 80% | 48,153 psi | 78% | 2385 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 41,989 psi | 68% | 2306 fps | 99.2% |
| Rottweil R 903 | <<locked>> | 80% | 35,476 psi | 57% | 2234 fps | 97.4% |
| Rottweil R 907 | <<locked>> | 92% | 48,356 psi | 78% | 2425 fps | 95% |
| Shooters World Long Rifle | <<locked>> | 88% | 41,669 psi | 67% | 2323 fps | 95.5% |
| Shooters World Match Rifle | <<locked>> | 80% | 43,671 psi | 70% | 2372 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 39,943 psi | 64% | 2290 fps | 98.9% |
| Shooters World SW4350 | <<locked>> | 92% | 44,657 psi | 72% | 2388 fps | 95.1% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 35,781 psi | 58% | 2267 fps | 96.6% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 44,672 psi | 72% | 2372 fps | 97.1% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 42,656 psi | 69% | 2352 fps | 98.4% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 44,947 psi | 72% | 2303 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 37,492 psi | 60% | 2188 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 92% | 46,514 psi | 75% | 2362 fps | 95.3% |
| Somchem S321 | <<locked>> | 80% | 49,705 psi | 80% | 2457 fps | 99.9% |
| Somchem S335 | <<locked>> | 80% | 44,585 psi | 72% | 2303 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 43,859 psi | 71% | 2362 fps | 98.5% |
| Somchem S355 | <<locked>> | 80% | 36,143 psi | 58% | 2238 fps | 97.4% |
| Somchem S365 | <<locked>> | 82% | 28,311 psi | 46% | 2139 fps | 95.7% |
| Vihtavuori N130 | <<locked>> | 80% | 50,444 psi | 81% | 2356 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 45,020 psi | 73% | 2297 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 41,060 psi | 66% | 2293 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 41,437 psi | 67% | 2297 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 34,360 psi | 55% | 2182 fps | 98.1% |
| Vihtavuori N160 | <<locked>> | 86% | 36,709 psi | 59% | 2270 fps | 95.4% |
| Vihtavuori N530 | <<locked>> | 80% | 46,209 psi | 74% | 2385 fps | 99.7% |
| Vihtavuori N540 | <<locked>> | 80% | 40,074 psi | 65% | 2287 fps | 99.9% |
| Vihtavuori N550 | <<locked>> | 86% | 36,172 psi | 58% | 2274 fps | 95% |
| Vihtavuori N555 | <<locked>> | 92% | 32,822 psi | 53% | 2264 fps | 95% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 30,530 psi | 49% | 2110 fps | 95.1% |
| Winchester 748 | <<locked>> | 80% | 45,614 psi | 73% | 2425 fps | 99.9% |
| Winchester 760 | <<locked>> | 92% | 44,889 psi | 72% | 2451 fps | 95% |
| Winchester StaBALL HD | <<locked>> | 96% | 30,893 psi | 50% | 2257 fps | 95% |
| Winchester StaBALL Match | <<locked>> | 80% | 42,032 psi | 68% | 2359 fps | 98.8% |
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 97 powders for .375 Ruger loaded with the .375 | 270gr | Impala RNFP KO. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 2,661 fps; across all powders the maximum-charge window runs from 1,545 fps to 2,661 fps. Accurate 4350 gives the best case fill at 100 %, and 97 of the 97 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (428 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 4350, 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. ReloadSwiss RS 60, Alliant Reloder-17, Alliant Power Pro 2000-MR rank at the top here: for .375 Ruger 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.