Load Specifications
Load data in caliber .375 Ruger with .375 | 300gr | SUS-TAC Solid Flat Nose bullet and 98 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: 23"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 84% | 55,579 psi | 90% | 2349 fps | 100% |
| Accurate 2495 | <<locked>> | 88% | 54,259 psi | 87% | 2372 fps | 100% |
| Accurate 2520 | <<locked>> | 84% | 55,956 psi | 90% | 2428 fps | 100% |
| Accurate 2700 | <<locked>> | 88% | 53,301 psi | 86% | 2372 fps | 97.3% |
| Accurate 3100ᴾ | <<locked>> | 100% | 41,191 psi | 66% | 2287 fps | 96.7% |
| Accurate 4064 | <<locked>> | 90% | 54,259 psi | 87% | 2411 fps | 100% |
| Accurate 4350 | <<locked>> | 98% | 53,722 psi | 87% | 2487 fps | 99.8% |
| ADI AR 2206H | <<locked>> | 86% | 54,563 psi | 88% | 2438 fps | 100% |
| ADI AR 2208 | <<locked>> | 92% | 55,463 psi | 89% | 2438 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 84% | 53,635 psi | 86% | 2395 fps | 100% |
| Alliant AR-Comp | <<locked>> | 84% | 54,505 psi | 88% | 2372 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 88% | 54,172 psi | 87% | 2543 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 92% | 55,651 psi | 90% | 2457 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 88% | 52,678 psi | 85% | 2434 fps | 99.9% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 55,085 psi | 89% | 2536 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 94% | 52,678 psi | 85% | 2520 fps | 100% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 39,392 psi | 63% | 2316 fps | 99.3% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 43,888 psi | 71% | 2454 fps | 98.7% |
| Baschieri & Pellagri 107 | <<locked>> | 86% | 54,215 psi | 87% | 2454 fps | 99.8% |
| Bofors RP3 | <<locked>> | 90% | 52,576 psi | 85% | 2428 fps | 100% |
| Bofors RP7 | <<locked>> | 94% | 52,808 psi | 85% | 2405 fps | 97.5% |
| Hodgdon Benchmark | <<locked>> | 84% | 55,317 psi | 89% | 2379 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 84% | 52,895 psi | 85% | 2421 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 82% | 54,708 psi | 88% | 2507 fps | 100% |
| Hodgdon H380 | <<locked>> | 90% | 53,650 psi | 86% | 2441 fps | 99.6% |
| Hodgdon H414 | <<locked>> | 96% | 53,055 psi | 85% | 2484 fps | 98.3% |
| Hodgdon H4350 | <<locked>> | 94% | 53,780 psi | 87% | 2451 fps | 97.1% |
| Hodgdon H4895 | <<locked>> | 86% | 55,100 psi | 89% | 2448 fps | 100% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 51,372 psi | 83% | 2428 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 88% | 54,549 psi | 88% | 2477 fps | 100% |
| Hodgdon Superformance | <<locked>> | 96% | 53,548 psi | 86% | 2513 fps | 98% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,563 psi | 57% | 1476 fps | 100% |
| Hodgdon VARGET | <<locked>> | 86% | 52,910 psi | 85% | 2408 fps | 100% |
| IMR 3031 | <<locked>> | 86% | 55,201 psi | 89% | 2431 fps | 100% |
| IMR 4064 | <<locked>> | 90% | 55,201 psi | 89% | 2425 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 88% | 55,042 psi | 89% | 2408 fps | 98.3% |
| IMR 4350 | <<locked>> | 98% | 52,997 psi | 85% | 2425 fps | 97.6% |
| IMR 4451 Enduron | <<locked>> | 94% | 54,752 psi | 88% | 2431 fps | 98.2% |
| IMR 4831ᴾ | <<locked>> | 100% | 54,389 psi | 88% | 2480 fps | 99.9% |
| IMR 4895 | <<locked>> | 88% | 53,983 psi | 87% | 2461 fps | 100% |
| IMR 8208 XBR | <<locked>> | 84% | 53,635 psi | 86% | 2395 fps | 100% |
| Lovex D073.6 | <<locked>> | 86% | 54,259 psi | 87% | 2418 fps | 100% |
| Lovex S060 | <<locked>> | 86% | 54,143 psi | 87% | 2375 fps | 100% |
| Lovex S062 | <<locked>> | 90% | 54,897 psi | 88% | 2421 fps | 100% |
| Lovex S065 | <<locked>> | 96% | 54,114 psi | 87% | 2425 fps | 99.2% |
| Lovex S070 | <<locked>> | 98% | 54,940 psi | 89% | 2454 fps | 98.6% |
| Norma 201 | <<locked>> | 86% | 53,417 psi | 86% | 2392 fps | 100% |
| Norma 202 | <<locked>> | 86% | 53,809 psi | 87% | 2392 fps | 100% |
| Norma 203B | <<locked>> | 90% | 55,390 psi | 89% | 2467 fps | 100% |
| Norma 204 | <<locked>> | 98% | 53,519 psi | 86% | 2467 fps | 96.5% |
| Norma MRPᴾ | <<locked>> | 100% | 43,976 psi | 71% | 2415 fps | 96.1% |
| Norma URP | <<locked>> | 98% | 52,808 psi | 85% | 2477 fps | 99.7% |
| Ramshot Big Game | <<locked>> | 90% | 55,970 psi | 90% | 2490 fps | 100% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 55,201 psi | 89% | 2520 fps | 99.1% |
| Ramshot TAC | <<locked>> | 84% | 53,722 psi | 87% | 2415 fps | 99.2% |
| Ramshot Wild Boar | <<locked>> | 84% | 53,359 psi | 86% | 2428 fps | 100% |
| Ramshot X-Terminator | <<locked>> | 82% | 54,404 psi | 88% | 2398 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,056 psi | 58% | 1512 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 90% | 53,969 psi | 87% | 2425 fps | 98.7% |
| ReloadSwiss RS 52 | <<locked>> | 86% | 53,127 psi | 86% | 2490 fps | 99.9% |
| ReloadSwiss RS 60 | <<locked>> | 94% | 56,173 psi | 90% | 2566 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 98% | 53,330 psi | 86% | 2507 fps | 99.7% |
| ReloadSwiss RS 70 | <<locked>> | 98% | 52,939 psi | 85% | 2530 fps | 99.6% |
| Rottweil R 901 | <<locked>> | 84% | 54,317 psi | 88% | 2372 fps | 100% |
| Rottweil R 902 | <<locked>> | 88% | 53,824 psi | 87% | 2388 fps | 100% |
| Rottweil R 903 | <<locked>> | 94% | 56,115 psi | 90% | 2464 fps | 100% |
| Rottweil R 907 | <<locked>> | 94% | 52,808 psi | 85% | 2405 fps | 97.5% |
| Shooters World Long Rifle | <<locked>> | 96% | 54,114 psi | 87% | 2425 fps | 99.2% |
| Shooters World Match Rifle | <<locked>> | 86% | 54,259 psi | 87% | 2418 fps | 100% |
| Shooters World Precision | <<locked>> | 90% | 54,897 psi | 88% | 2421 fps | 100% |
| Shooters World SW4350 | <<locked>> | 98% | 54,940 psi | 89% | 2454 fps | 98.6% |
| SNPE Vectan SP 11 | <<locked>> | 92% | 54,186 psi | 87% | 2474 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 86% | 55,782 psi | 90% | 2441 fps | 99.7% |
| SNPE Vectan SP 9 | <<locked>> | 86% | 53,055 psi | 85% | 2415 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 86% | 54,853 psi | 88% | 2336 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 92% | 55,085 psi | 89% | 2336 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 96% | 54,476 psi | 88% | 2385 fps | 98.2% |
| Somchem S321 | <<locked>> | 82% | 54,636 psi | 88% | 2425 fps | 100% |
| Somchem S335 | <<locked>> | 86% | 54,288 psi | 87% | 2336 fps | 100% |
| Somchem S341 | <<locked>> | 86% | 55,288 psi | 89% | 2431 fps | 100% |
| Somchem S355 | <<locked>> | 92% | 52,997 psi | 85% | 2421 fps | 100% |
| Somchem S365ᴾ | <<locked>> | 100% | 50,850 psi | 82% | 2480 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 47,253 psi | 76% | 2379 fps | 96.5% |
| Vihtavuori N130 | <<locked>> | 82% | 54,578 psi | 88% | 2303 fps | 100% |
| Vihtavuori N133 | <<locked>> | 86% | 55,114 psi | 89% | 2323 fps | 100% |
| Vihtavuori N135 | <<locked>> | 88% | 53,708 psi | 87% | 2359 fps | 100% |
| Vihtavuori N140 | <<locked>> | 88% | 54,360 psi | 88% | 2372 fps | 100% |
| Vihtavuori N150 | <<locked>> | 94% | 54,375 psi | 88% | 2402 fps | 100% |
| Vihtavuori N160 | <<locked>> | 98% | 55,347 psi | 89% | 2470 fps | 99.8% |
| Vihtavuori N530 | <<locked>> | 84% | 54,056 psi | 87% | 2395 fps | 100% |
| Vihtavuori N540 | <<locked>> | 90% | 55,956 psi | 90% | 2415 fps | 100% |
| Vihtavuori N550 | <<locked>> | 98% | 54,462 psi | 88% | 2480 fps | 99.7% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 43,221 psi | 70% | 2379 fps | 99.2% |
| Winchester 6.5 StaBALL | <<locked>> | 98% | 55,811 psi | 90% | 2454 fps | 100% |
| Winchester 748 | <<locked>> | 84% | 53,954 psi | 87% | 2438 fps | 100% |
| Winchester 760 | <<locked>> | 96% | 53,272 psi | 86% | 2487 fps | 98.3% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 35,273 psi | 57% | 2323 fps | 99.3% |
| Winchester StaBALL Match | <<locked>> | 86% | 52,794 psi | 85% | 2421 fps | 100% |
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% | 49,052 psi | 79% | 2270 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 41,916 psi | 68% | 2215 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 48,776 psi | 79% | 2339 fps | 100% |
| Accurate 2700 | <<locked>> | 82% | 43,874 psi | 71% | 2234 fps | 95.2% |
| Accurate 3100 | <<locked>> | 96% | 35,839 psi | 58% | 2195 fps | 95% |
| Accurate 4064 | <<locked>> | 80% | 39,624 psi | 64% | 2211 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 30,937 psi | 50% | 2106 fps | 95.2% |
| ADI AR 2206H | <<locked>> | 80% | 45,223 psi | 73% | 2306 fps | 99.6% |
| ADI AR 2208 | <<locked>> | 80% | 38,508 psi | 62% | 2182 fps | 98.1% |
| ADI Benchmark 8208 | <<locked>> | 80% | 47,311 psi | 76% | 2313 fps | 100% |
| Alliant AR-Comp | <<locked>> | 80% | 47,761 psi | 77% | 2293 fps | 100% |
| Alliant Power Pro 2000-MR | 65.5 gr | 80% | 41,104 psi | 66% | 2339 fps | 98.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 38,145 psi | 61% | 2201 fps | 99.2% |
| Alliant Reloder-15 | <<locked>> | 80% | 40,944 psi | 66% | 2254 fps | 98.7% |
| Alliant Reloder-16 | <<locked>> | 82% | 31,589 psi | 51% | 2119 fps | 95.3% |
| Alliant Reloder-17 | 64.5 gr | 80% | 32,909 psi | 53% | 2178 fps | 97.7% |
| Alliant Reloder-23 | <<locked>> | 88% | 27,369 psi | 44% | 2041 fps | 95% |
| Alliant Reloder-26 | <<locked>> | 92% | 33,286 psi | 54% | 2234 fps | 95.2% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 44,469 psi | 72% | 2313 fps | 98.9% |
| Bofors RP3 | <<locked>> | 80% | 37,869 psi | 61% | 2208 fps | 99.2% |
| Bofors RP7 | <<locked>> | 88% | 43,903 psi | 71% | 2270 fps | 95.6% |
| Hodgdon Benchmark | <<locked>> | 80% | 49,081 psi | 79% | 2300 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 46,151 psi | 74% | 2333 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 80% | 50,952 psi | 82% | 2457 fps | 99.9% |
| Hodgdon H380 | <<locked>> | 80% | 38,551 psi | 62% | 2205 fps | 97.1% |
| Hodgdon H414 | <<locked>> | 88% | 40,756 psi | 66% | 2293 fps | 95.5% |
| Hodgdon H4350 | <<locked>> | 90% | 47,398 psi | 76% | 2359 fps | 95.7% |
| Hodgdon H4895 | <<locked>> | 80% | 45,658 psi | 74% | 2316 fps | 99.8% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 27,166 psi | 44% | 1991 fps | 95.3% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 41,597 psi | 67% | 2293 fps | 99.7% |
| Hodgdon Superformance | 76.7 gr | 90% | 43,323 psi | 70% | 2356 fps | 95.5% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,455 psi | 43% | 1316 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 43,772 psi | 71% | 2274 fps | 99.7% |
| IMR 3031 | <<locked>> | 80% | 45,353 psi | 73% | 2306 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 40,393 psi | 65% | 2208 fps | 98.7% |
| IMR 4166 Enduron | <<locked>> | 80% | 42,859 psi | 69% | 2228 fps | 95.9% |
| IMR 4350 | <<locked>> | 92% | 43,932 psi | 71% | 2293 fps | 95.6% |
| IMR 4451 Enduron | <<locked>> | 84% | 40,350 psi | 65% | 2208 fps | 95% |
| IMR 4831 | <<locked>> | 84% | 32,314 psi | 52% | 2119 fps | 95.8% |
| IMR 4895 | <<locked>> | 80% | 41,930 psi | 68% | 2280 fps | 99.3% |
| IMR 8208 XBR | <<locked>> | 80% | 47,311 psi | 76% | 2313 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 44,512 psi | 72% | 2290 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 45,136 psi | 73% | 2251 fps | 99.6% |
| Lovex S062 | <<locked>> | 80% | 40,306 psi | 65% | 2211 fps | 99.7% |
| Lovex S065 | <<locked>> | 82% | 35,346 psi | 57% | 2123 fps | 95.1% |
| Lovex S070 | <<locked>> | 88% | 40,277 psi | 65% | 2231 fps | 95.5% |
| Norma 201 | <<locked>> | 80% | 44,396 psi | 72% | 2267 fps | 99.9% |
| Norma 202 | <<locked>> | 80% | 44,672 psi | 72% | 2270 fps | 100% |
| Norma 203B | <<locked>> | 80% | 40,306 psi | 65% | 2244 fps | 99% |
| Norma 204 | <<locked>> | 96% | 50,038 psi | 81% | 2418 fps | 95.7% |
| Norma MRP | <<locked>> | 98% | 41,147 psi | 66% | 2365 fps | 95.2% |
| Norma URP | <<locked>> | 82% | 31,575 psi | 51% | 2113 fps | 95.2% |
| Ramshot Big Game | <<locked>> | 80% | 39,827 psi | 64% | 2257 fps | 98.8% |
| Ramshot Hunter | <<locked>> | 88% | 37,434 psi | 60% | 2238 fps | 95.3% |
| Ramshot TAC | <<locked>> | 80% | 47,152 psi | 76% | 2320 fps | 98.3% |
| Ramshot Wild Boar | <<locked>> | 80% | 46,688 psi | 75% | 2336 fps | 99.7% |
| Ramshot X-Terminator | <<locked>> | 80% | 50,894 psi | 82% | 2352 fps | 99.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,818 psi | 43% | 1348 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 39,030 psi | 63% | 2192 fps | 95.5% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 43,120 psi | 69% | 2343 fps | 99.1% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 34,998 psi | 56% | 2234 fps | 99.8% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 33,040 psi | 53% | 2169 fps | 95.5% |
| ReloadSwiss RS 70 | <<locked>> | 86% | 35,389 psi | 57% | 2221 fps | 95.5% |
| Rottweil R 901 | <<locked>> | 80% | 48,298 psi | 78% | 2293 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 42,235 psi | 68% | 2224 fps | 99.8% |
| Rottweil R 903 | <<locked>> | 80% | 35,563 psi | 57% | 2159 fps | 98.6% |
| Rottweil R 907 | <<locked>> | 88% | 43,903 psi | 71% | 2270 fps | 95.6% |
| Shooters World Long Rifle | <<locked>> | 82% | 35,346 psi | 57% | 2123 fps | 95.1% |
| Shooters World Match Rifle | <<locked>> | 80% | 44,512 psi | 72% | 2290 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 40,306 psi | 65% | 2211 fps | 99.7% |
| Shooters World SW4350 | <<locked>> | 88% | 40,277 psi | 65% | 2231 fps | 95.5% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 36,492 psi | 59% | 2198 fps | 98.2% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 45,571 psi | 73% | 2300 fps | 98.5% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 43,714 psi | 70% | 2280 fps | 99.4% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 45,716 psi | 74% | 2221 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 38,087 psi | 61% | 2110 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 41,959 psi | 68% | 2205 fps | 95.7% |
| Somchem S321 | <<locked>> | 80% | 51,227 psi | 83% | 2382 fps | 100% |
| Somchem S335 | <<locked>> | 80% | 45,324 psi | 73% | 2221 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 45,281 psi | 73% | 2297 fps | 99.6% |
| Somchem S355 | <<locked>> | 80% | 36,477 psi | 59% | 2165 fps | 98.6% |
| Somchem S365 | <<locked>> | 80% | 26,484 psi | 43% | 2024 fps | 96.6% |
| Somchem S385 | <<locked>> | 98% | 44,353 psi | 71% | 2333 fps | 95.7% |
| Vihtavuori N130 | <<locked>> | 80% | 51,532 psi | 83% | 2267 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 46,064 psi | 74% | 2211 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 41,785 psi | 67% | 2205 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 42,235 psi | 68% | 2215 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 34,577 psi | 56% | 2106 fps | 99.2% |
| Vihtavuori N160 | <<locked>> | 82% | 32,822 psi | 53% | 2110 fps | 95.6% |
| Vihtavuori N530 | <<locked>> | 80% | 47,471 psi | 76% | 2310 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 40,654 psi | 65% | 2208 fps | 100% |
| Vihtavuori N550 | <<locked>> | 82% | 32,329 psi | 52% | 2113 fps | 95.2% |
| Vihtavuori N555 | <<locked>> | 88% | 29,182 psi | 47% | 2103 fps | 95.1% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 30,690 psi | 49% | 2047 fps | 97% |
| Winchester 748 | <<locked>> | 80% | 47,210 psi | 76% | 2349 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 40,930 psi | 66% | 2297 fps | 95.5% |
| Winchester StaBALL HD | <<locked>> | 92% | 27,296 psi | 44% | 2100 fps | 95.3% |
| Winchester StaBALL Match | <<locked>> | 80% | 43,134 psi | 69% | 2283 fps | 99.7% |
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 98 powders for .375 Ruger loaded with the .375 | 300gr | SUS-TAC Solid Flat Nose. ReloadSwiss RS 60 delivers the highest muzzle velocity at 2,566 fps; across all powders the maximum-charge window runs from 1,476 fps to 2,566 fps. Accurate 3100 gives the best case fill at 100 %, and 98 of the 98 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (428 MPa), the top charges use 57–90 %, leaving at least 10 % headroom. The 300.0 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 .375 Ruger with the .375 | 300gr | SUS-TAC Solid Flat Nose 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.