Load Specifications
Bullet Manufacturer:Hammer
Bullet Weight:256 gr
Bullet Diameter:0.375"
Bullet Length:<<locked>>
Caliber:.375 Ruger load data
Case Length (l3):2.572"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:99 Grains of Water
Primer Size:Large Rifle Magnum (LRM)
Barrel Length:23"
Max. allowed Pressure:62,076 psi
Recommended Twist Rate:1:6.0
Load data in caliber .375 Ruger with .375 | 256gr | Hammer Stone Hammer bullet and 100 powders. The key underlying parameters are shown in the table above.
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: 23"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 88% | 55,477 psi | 89% | 2539 fps | 100% |
| Accurate 2460 | <<locked>> | 84% | 54,012 psi | 87% | 2562 fps | 100% |
| Accurate 2495 | <<locked>> | 92% | 53,287 psi | 86% | 2556 fps | 100% |
| Accurate 2520 | <<locked>> | 88% | 55,724 psi | 90% | 2618 fps | 100% |
| Accurate 4064 | <<locked>> | 94% | 53,098 psi | 86% | 2595 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 48,646 psi | 78% | 2598 fps | 98.2% |
| Accurate LT-30 | <<locked>> | 82% | 54,926 psi | 88% | 2490 fps | 100% |
| Accurate LT-32 | <<locked>> | 82% | 55,390 psi | 89% | 2513 fps | 100% |
| ADI AR 2206H | <<locked>> | 90% | 54,621 psi | 88% | 2625 fps | 99.6% |
| ADI AR 2208 | <<locked>> | 96% | 55,448 psi | 89% | 2618 fps | 99.4% |
| ADI AR 2219 | <<locked>> | 82% | 55,782 psi | 90% | 2602 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 88% | 53,911 psi | 87% | 2585 fps | 99.9% |
| Alliant AR-Comp | <<locked>> | 88% | 53,867 psi | 87% | 2569 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 84% | 55,332 psi | 89% | 2680 fps | 99.9% |
| Alliant Power Pro 2000-MR | <<locked>> | 92% | 53,983 psi | 87% | 2720 fps | 99.3% |
| Alliant Reloder- TS 15.5 | <<locked>> | 96% | 55,027 psi | 89% | 2638 fps | 99.9% |
| Alliant Reloder-10x | <<locked>> | 84% | 55,361 psi | 89% | 2546 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 94% | 55,695 psi | 90% | 2657 fps | 99.5% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 47,906 psi | 77% | 2602 fps | 98.2% |
| Alliant Reloder-17ᴾ | <<locked>> | 100% | 55,593 psi | 90% | 2743 fps | 100% |
| Baschieri & Pellagri 106 | <<locked>> | 82% | 53,998 psi | 87% | 2484 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 90% | 54,331 psi | 88% | 2635 fps | 99% |
| Bofors RP3 | <<locked>> | 96% | 55,564 psi | 90% | 2654 fps | 100% |
| Bofors RP7ᴾ | <<locked>> | 100% | 56,159 psi | 90% | 2615 fps | 96.2% |
| Hodgdon Benchmark | <<locked>> | 88% | 55,811 psi | 90% | 2569 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 88% | 52,663 psi | 85% | 2608 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 86% | 54,331 psi | 88% | 2690 fps | 99.4% |
| Hodgdon H322 | <<locked>> | 84% | 54,346 psi | 88% | 2582 fps | 100% |
| Hodgdon H335 | <<locked>> | 84% | 55,579 psi | 90% | 2605 fps | 100% |
| Hodgdon H380 | <<locked>> | 94% | 53,301 psi | 86% | 2612 fps | 98.4% |
| Hodgdon H414ᴾ | <<locked>> | 100% | 52,141 psi | 84% | 2644 fps | 96.2% |
| Hodgdon H4895 | <<locked>> | 90% | 55,100 psi | 89% | 2635 fps | 99.8% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 43,990 psi | 71% | 2493 fps | 98.7% |
| Hodgdon LEVERevolution | <<locked>> | 92% | 53,780 psi | 87% | 2657 fps | 99.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 34,809 psi | 56% | 1585 fps | 100% |
| Hodgdon VARGET | <<locked>> | 90% | 53,127 psi | 86% | 2592 fps | 99.7% |
| IMR 3031 | <<locked>> | 90% | 54,534 psi | 88% | 2621 fps | 100% |
| IMR 4064 | <<locked>> | 94% | 54,940 psi | 89% | 2602 fps | 99.4% |
| IMR 4166 Enduron | <<locked>> | 92% | 55,637 psi | 90% | 2582 fps | 96.7% |
| IMR 4198 | <<locked>> | 84% | 55,564 psi | 90% | 2510 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 98% | 54,810 psi | 88% | 2598 fps | 96.5% |
| IMR 4831ᴾ | <<locked>> | 100% | 46,311 psi | 75% | 2543 fps | 97.8% |
| IMR 4895 | <<locked>> | 92% | 53,650 psi | 86% | 2641 fps | 99.6% |
| IMR 8208 XBR | <<locked>> | 88% | 53,911 psi | 87% | 2585 fps | 99.9% |
| Lovex D073.5 | <<locked>> | 84% | 53,983 psi | 87% | 2572 fps | 100% |
| Lovex D073.6 | <<locked>> | 90% | 53,838 psi | 87% | 2605 fps | 100% |
| Lovex S060 | <<locked>> | 90% | 54,621 psi | 88% | 2559 fps | 99.6% |
| Lovex S062 | <<locked>> | 94% | 54,563 psi | 88% | 2602 fps | 100% |
| Lovex S065ᴾ | <<locked>> | 100% | 53,490 psi | 86% | 2589 fps | 97.7% |
| Lovex S070ᴾ | <<locked>> | 100% | 50,981 psi | 82% | 2569 fps | 96.1% |
| Norma 201 | <<locked>> | 90% | 53,330 psi | 86% | 2575 fps | 99.9% |
| Norma 202 | <<locked>> | 90% | 53,780 psi | 87% | 2582 fps | 100% |
| Norma 203B | <<locked>> | 94% | 54,795 psi | 88% | 2644 fps | 99.7% |
| Norma URPᴾ | <<locked>> | 100% | 48,385 psi | 78% | 2592 fps | 98% |
| Ramshot Big Game | <<locked>> | 94% | 55,405 psi | 89% | 2667 fps | 99.6% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 47,645 psi | 77% | 2579 fps | 96.1% |
| Ramshot TAC | <<locked>> | 88% | 54,302 psi | 87% | 2592 fps | 98% |
| Ramshot Wild Boar | <<locked>> | 88% | 53,388 psi | 86% | 2612 fps | 99.5% |
| Ramshot X-Terminator | <<locked>> | 86% | 54,897 psi | 88% | 2582 fps | 99.5% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 35,157 psi | 57% | 1621 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 84% | 53,534 psi | 86% | 2572 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 94% | 53,882 psi | 87% | 2592 fps | 97.1% |
| ReloadSwiss RS 52 | <<locked>> | 92% | 55,898 psi | 90% | 2720 fps | 99.5% |
| ReloadSwiss RS 60 | <<locked>> | 98% | 55,419 psi | 89% | 2746 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 48,414 psi | 78% | 2615 fps | 97.9% |
| ReloadSwiss RS 70ᴾ | <<locked>> | 100% | 49,255 psi | 79% | 2631 fps | 97.4% |
| Rottweil R 901 | <<locked>> | 88% | 54,389 psi | 88% | 2566 fps | 100% |
| Rottweil R 902 | <<locked>> | 92% | 53,737 psi | 87% | 2572 fps | 99.9% |
| Rottweil R 903 | <<locked>> | 98% | 55,201 psi | 89% | 2641 fps | 99.9% |
| Rottweil R 907ᴾ | <<locked>> | 100% | 56,159 psi | 90% | 2615 fps | 96.2% |
| Shooters World Long Rifleᴾ | <<locked>> | 100% | 53,490 psi | 86% | 2589 fps | 97.7% |
| Shooters World Match Rifle | <<locked>> | 90% | 53,838 psi | 87% | 2605 fps | 100% |
| Shooters World Precision | <<locked>> | 94% | 54,563 psi | 88% | 2602 fps | 100% |
| Shooters World SW4350ᴾ | <<locked>> | 100% | 50,981 psi | 82% | 2569 fps | 96.1% |
| Shooters World Tactical Rifle | <<locked>> | 82% | 53,243 psi | 86% | 2539 fps | 99.8% |
| SNPE Vectan SP 11 | <<locked>> | 96% | 53,374 psi | 86% | 2648 fps | 99.5% |
| SNPE Vectan SP 3 | <<locked>> | 84% | 56,159 psi | 90% | 2566 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 90% | 56,173 psi | 90% | 2621 fps | 98.6% |
| SNPE Vectan SP 9 | <<locked>> | 90% | 52,939 psi | 85% | 2595 fps | 99.5% |
| SNPE Vectan Tubal 3000 | <<locked>> | 90% | 55,230 psi | 89% | 2526 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 96% | 55,100 psi | 89% | 2523 fps | 100% |
| SNPE Vectan Tubal 7000ᴾ | <<locked>> | 100% | 54,302 psi | 87% | 2549 fps | 96.4% |
| Somchem S321 | <<locked>> | 86% | 54,984 psi | 89% | 2615 fps | 100% |
| Somchem S335 | <<locked>> | 90% | 54,447 psi | 88% | 2526 fps | 100% |
| Somchem S341 | <<locked>> | 90% | 55,477 psi | 89% | 2612 fps | 99.6% |
| Somchem S355 | <<locked>> | 98% | 55,738 psi | 90% | 2641 fps | 99.9% |
| Somchem S365ᴾ | <<locked>> | 100% | 43,091 psi | 69% | 2543 fps | 99.6% |
| Vihtavuori N130 | <<locked>> | 86% | 55,201 psi | 89% | 2500 fps | 100% |
| Vihtavuori N133 | <<locked>> | 90% | 55,201 psi | 89% | 2513 fps | 100% |
| Vihtavuori N135 | <<locked>> | 92% | 52,968 psi | 85% | 2546 fps | 100% |
| Vihtavuori N140 | <<locked>> | 92% | 54,099 psi | 87% | 2559 fps | 100% |
| Vihtavuori N150 | <<locked>> | 98% | 53,838 psi | 87% | 2579 fps | 100% |
| Vihtavuori N160ᴾ | <<locked>> | 100% | 50,923 psi | 82% | 2589 fps | 98.3% |
| Vihtavuori N530 | <<locked>> | 88% | 54,375 psi | 88% | 2585 fps | 100% |
| Vihtavuori N540 | <<locked>> | 94% | 55,912 psi | 90% | 2602 fps | 100% |
| Vihtavuori N550ᴾ | <<locked>> | 100% | 50,082 psi | 81% | 2595 fps | 98.1% |
| Winchester 6.5 StaBALLᴾ | <<locked>> | 100% | 52,011 psi | 84% | 2575 fps | 99.7% |
| Winchester 748 | <<locked>> | 88% | 53,737 psi | 87% | 2625 fps | 100% |
| Winchester 760ᴾ | <<locked>> | 100% | 52,344 psi | 84% | 2648 fps | 96.3% |
| Winchester StaBALL Match | <<locked>> | 90% | 52,605 psi | 85% | 2602 fps | 99.7% |
Start Load - Barrel Length: 23"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 80% | 43,323 psi | 70% | 2375 fps | 100% |
| Accurate 2460 | <<locked>> | 80% | 47,239 psi | 76% | 2470 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 35,868 psi | 58% | 2297 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 42,424 psi | 68% | 2428 fps | 99.8% |
| Accurate 4064 | <<locked>> | 80% | 33,881 psi | 55% | 2280 fps | 99.3% |
| Accurate 4350 | <<locked>> | 92% | 36,753 psi | 59% | 2392 fps | 95.1% |
| Accurate LT-30 | <<locked>> | 80% | 51,634 psi | 83% | 2448 fps | 100% |
| Accurate LT-32 | <<locked>> | 80% | 52,025 psi | 84% | 2470 fps | 100% |
| ADI AR 2206H | <<locked>> | 80% | 39,740 psi | 64% | 2382 fps | 97.3% |
| ADI AR 2208 | <<locked>> | 82% | 36,027 psi | 58% | 2290 fps | 95.4% |
| ADI AR 2219 | <<locked>> | 80% | 52,069 psi | 84% | 2552 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 80% | 41,756 psi | 67% | 2395 fps | 98.8% |
| Alliant AR-Comp | <<locked>> | 80% | 41,220 psi | 66% | 2398 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 80% | 48,443 psi | 78% | 2579 fps | 99.4% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 38,508 psi | 62% | 2444 fps | 95.8% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 33,170 psi | 53% | 2264 fps | 96.3% |
| Alliant Reloder-10x | <<locked>> | 80% | 48,921 psi | 79% | 2464 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 35,607 psi | 57% | 2316 fps | 95.5% |
| Alliant Reloder-16 | <<locked>> | 92% | 37,579 psi | 61% | 2402 fps | 95.2% |
| Alliant Reloder-17 | <<locked>> | 84% | 32,590 psi | 53% | 2316 fps | 95.2% |
| Baschieri & Pellagri 106 | <<locked>> | 80% | 50,792 psi | 82% | 2444 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 38,754 psi | 62% | 2379 fps | 95.9% |
| Bofors RP3 | <<locked>> | 80% | 32,387 psi | 52% | 2260 fps | 96.2% |
| Bofors RP7 | <<locked>> | 98% | 52,721 psi | 85% | 2566 fps | 95.5% |
| Hodgdon Benchmark | <<locked>> | 80% | 43,787 psi | 71% | 2392 fps | 99.4% |
| Hodgdon BL-C2 | <<locked>> | 80% | 40,103 psi | 65% | 2411 fps | 99% |
| Hodgdon CFE223 | <<locked>> | 80% | 44,106 psi | 71% | 2533 fps | 97.9% |
| Hodgdon H322 | <<locked>> | 80% | 47,776 psi | 77% | 2493 fps | 100% |
| Hodgdon H335 | <<locked>> | 80% | 48,501 psi | 78% | 2513 fps | 100% |
| Hodgdon H380 | <<locked>> | 86% | 41,017 psi | 66% | 2415 fps | 95.8% |
| Hodgdon H414 | <<locked>> | 98% | 48,675 psi | 78% | 2592 fps | 95.4% |
| Hodgdon H4895 | <<locked>> | 80% | 40,045 psi | 65% | 2395 fps | 97.9% |
| Hodgdon Hybrid 100V | <<locked>> | 90% | 32,126 psi | 52% | 2257 fps | 95.1% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 36,042 psi | 58% | 2362 fps | 97.4% |
| Hodgdon TrailBoss | <<locked>> | 80% | 25,933 psi | 42% | 1417 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 38,508 psi | 62% | 2349 fps | 97.5% |
| IMR 3031 | <<locked>> | 80% | 39,204 psi | 63% | 2398 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 35,592 psi | 57% | 2277 fps | 95.6% |
| IMR 4166 Enduron | <<locked>> | 88% | 49,095 psi | 79% | 2487 fps | 95.3% |
| IMR 4198 | <<locked>> | 80% | 49,255 psi | 79% | 2431 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 94% | 48,544 psi | 78% | 2507 fps | 95% |
| IMR 4831 | <<locked>> | 94% | 38,087 psi | 61% | 2398 fps | 95.7% |
| IMR 4895 | <<locked>> | 80% | 36,434 psi | 59% | 2346 fps | 96.5% |
| IMR 8208 XBR | <<locked>> | 80% | 41,756 psi | 67% | 2395 fps | 98.8% |
| Lovex D073.5 | <<locked>> | 80% | 47,065 psi | 76% | 2474 fps | 99.8% |
| Lovex D073.6 | <<locked>> | 80% | 38,363 psi | 62% | 2365 fps | 99.4% |
| Lovex S060 | <<locked>> | 80% | 40,393 psi | 65% | 2333 fps | 97.5% |
| Lovex S062 | <<locked>> | 80% | 35,288 psi | 57% | 2283 fps | 97.5% |
| Lovex S065 | <<locked>> | 92% | 42,003 psi | 68% | 2405 fps | 95% |
| Lovex S070 | <<locked>> | 98% | 47,935 psi | 77% | 2523 fps | 95.4% |
| Norma 201 | <<locked>> | 80% | 39,030 psi | 63% | 2346 fps | 98.3% |
| Norma 202 | <<locked>> | 80% | 39,218 psi | 63% | 2359 fps | 99.7% |
| Norma 203B | <<locked>> | 80% | 34,998 psi | 56% | 2306 fps | 96% |
| Norma URP | <<locked>> | 92% | 37,289 psi | 60% | 2392 fps | 95.1% |
| Ramshot Big Game | <<locked>> | 80% | 34,461 psi | 56% | 2313 fps | 95.4% |
| Ramshot Hunter | <<locked>> | 98% | 44,585 psi | 72% | 2526 fps | 95.2% |
| Ramshot TAC | <<locked>> | 80% | 41,713 psi | 67% | 2388 fps | 95.1% |
| Ramshot Wild Boar | <<locked>> | 80% | 40,901 psi | 66% | 2411 fps | 97.6% |
| Ramshot X-Terminator | <<locked>> | 80% | 45,368 psi | 73% | 2441 fps | 98.4% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,165 psi | 42% | 1450 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 46,862 psi | 75% | 2477 fps | 99.9% |
| ReloadSwiss RS 50 | <<locked>> | 90% | 47,268 psi | 76% | 2493 fps | 95.6% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 36,767 psi | 59% | 2402 fps | 95.9% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 30,458 psi | 49% | 2274 fps | 96.9% |
| ReloadSwiss RS 62 | <<locked>> | 94% | 39,436 psi | 64% | 2457 fps | 95.6% |
| ReloadSwiss RS 70 | <<locked>> | 96% | 42,960 psi | 69% | 2520 fps | 95.6% |
| Rottweil R 901 | <<locked>> | 80% | 42,873 psi | 69% | 2392 fps | 99.9% |
| Rottweil R 902 | <<locked>> | 80% | 37,202 psi | 60% | 2303 fps | 97.9% |
| Rottweil R 903 | <<locked>> | 80% | 30,530 psi | 49% | 2211 fps | 95.1% |
| Rottweil R 907 | <<locked>> | 98% | 52,721 psi | 85% | 2566 fps | 95.5% |
| Shooters World Long Rifle | <<locked>> | 92% | 42,003 psi | 68% | 2405 fps | 95% |
| Shooters World Match Rifle | <<locked>> | 80% | 38,363 psi | 62% | 2365 fps | 99.4% |
| Shooters World Precision | <<locked>> | 80% | 35,288 psi | 57% | 2283 fps | 97.5% |
| Shooters World SW4350 | <<locked>> | 98% | 47,935 psi | 77% | 2523 fps | 95.4% |
| Shooters World Tactical Rifle | <<locked>> | 80% | 49,588 psi | 80% | 2490 fps | 99.6% |
| SNPE Vectan SP 11 | <<locked>> | 82% | 33,779 psi | 54% | 2303 fps | 95.2% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 49,588 psi | 80% | 2480 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 39,798 psi | 64% | 2365 fps | 95.2% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 38,276 psi | 62% | 2352 fps | 96.9% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 40,567 psi | 65% | 2313 fps | 99.8% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 33,417 psi | 54% | 2192 fps | 99.5% |
| SNPE Vectan Tubal 7000 | <<locked>> | 98% | 50,604 psi | 82% | 2497 fps | 95.7% |
| Somchem S321 | <<locked>> | 80% | 45,005 psi | 73% | 2467 fps | 99.5% |
| Somchem S335 | <<locked>> | 80% | 40,118 psi | 65% | 2316 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 39,494 psi | 64% | 2365 fps | 97.2% |
| Somchem S355 | <<locked>> | 80% | 31,589 psi | 51% | 2221 fps | 95.2% |
| Somchem S365 | <<locked>> | 88% | 29,385 psi | 47% | 2244 fps | 95.5% |
| Vihtavuori N130 | <<locked>> | 80% | 45,948 psi | 74% | 2379 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 40,727 psi | 66% | 2313 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 36,085 psi | 58% | 2297 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 37,028 psi | 60% | 2300 fps | 99.7% |
| Vihtavuori N150 | <<locked>> | 80% | 29,965 psi | 48% | 2165 fps | 96.2% |
| Vihtavuori N160 | <<locked>> | 92% | 39,204 psi | 63% | 2395 fps | 95.6% |
| Vihtavuori N530 | <<locked>> | 80% | 41,756 psi | 67% | 2392 fps | 98.9% |
| Vihtavuori N540 | <<locked>> | 80% | 35,636 psi | 57% | 2287 fps | 99.2% |
| Vihtavuori N550 | <<locked>> | 92% | 38,406 psi | 62% | 2395 fps | 95.2% |
| Winchester 6.5 StaBALL | <<locked>> | 86% | 32,706 psi | 53% | 2231 fps | 95.5% |
| Winchester 748 | <<locked>> | 80% | 40,886 psi | 66% | 2428 fps | 99.3% |
| Winchester 760 | <<locked>> | 98% | 48,936 psi | 79% | 2595 fps | 95.5% |
| Winchester StaBALL Match | <<locked>> | 80% | 37,608 psi | 61% | 2356 fps | 97.4% |
ᴾ possible press load - work up slowly to this load while watching for signs of excessive pressure.
This overview compares 111 powders for .375 Ruger loaded with the .375 | 256gr | Hammer Stone Hammer. ReloadSwiss RS 60 delivers the highest muzzle velocity at 2,746 fps; across all powders the maximum-charge window runs from 1,585 fps to 2,746 fps. Accurate 3100 gives the best case fill at 100 %, and 111 of the 111 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (428 MPa), the top charges use 49–90 %, leaving at least 10 % headroom. The 256.0 gr projectile in 0.375" calls for a 1:6.0 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. 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.